| Home |
| Search |
| Today's Posts |
|
#1
Posted to rec.audio.tubes
|
|||
|
|||
Brook 10c servo bias
Flipper's posts disappear so the 10c thread looks like David and
Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? A problem with self-regulating bias is that asymmetric current in the ouput valves, particularly at high signal levels, contains a DC component that the regulator interprets as an increase in bias current. The regulator will tend to respond by reducing the bias current, thus making the asymmetry worse. Triode operation in particular produces predominantly 2H distortion, so a symmetrical input signal will always result in a DC component in the output, increasing with signal amplitude. In addition, in PP AB, asymmetry increases rapidly when the output stage is driven into class B. The result, as with ordinary cathode bias, is a bias current that always wanders and sometimes strays considerably. A crude and probably intrusive solution is to impose a fixed limit on the output voltage of the regulator. With cathode bias this could be done by connecting a zener accross the cathode capacitor. A potentially better solution is to condition the input to the regulator to remove the assymmetry. Ideally, a none- inverting amp with congruent distortion and clipping characteristics can be used for this purpose. Gain in the regulator circuit also allows for tighter control, resulting in fixed bias. It then makes more sense to apply the bias control voltage to the grid than to the low-impedance cathode. The posted circuit for the 10c doesn't show voltages, unfortunately, but it looks like an attempt at the perfect solution. If the triode in the current detector part of the circuit is set up right, then it should have equal distortion, and clip at the same point, but in the opposite direction, as the output valves. The output from the current detector then integrates to a constant DC value, which is used to determine the bias voltage. I wonder, as the control circuit valves age along with the output valves, whether they maintain the bias point in the same place relative to the characteristics of the output valves? That would solve a problem of fixed bias, which generally maintains a given current regardless of ageing, and so drifts in relation to valve characteristics. Morgan Jones in one of his books shows a comparatively crude SS version of the same circuit, using IIRC an opamp and a zener in place of the first triode in the Brook's control circuit, followed by the integrating LPF, and perhaps the other half of the opamp for the bias voltage output. Maybe discrete transistors instead of opamps...can't remember. The Butcher's combination of loose regulation and tight fixed limiting, with incompletely-bypassed SS in the signal path, looks like a bodge. Considering his amps are well specified for purpose (ie big enough), however, there is possibly enough headroom so the circuit is largely redundant, because it's set to allow some drift before doing its thing. To paraphrase Jim, from time long gone, if it's big enough, nothing else matters. On a related matter, while I'm passing, can anyone guide me to a clear definition of standard line level? I'm looking for an accepted standard for headroom. I have it in my head that a system should allow for 18dB above rms listening level. Tried looking but there's so much gobbledegook... To know how intrusive a limiter might be, either with the Butcher's bodge or my nascent headphone amp, it should strictly be necessary to know this. Also what kind of distribution, and what standard deviation, a piece of recorded music may have within that limit. The widespread use of compression in recording and broadcasting rather muddies the issue. I'd like to know the standard, rather than the common reality. Ian |
|
#2
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 19, 8:20*pm, flipper wrote:
On Sat, 19 Nov 2011 11:06:11 -0800 (PST), Ian Iveson wrote: Flipper's posts disappear Sorry. I suppose one of these days I should figure out where that setting hides in my news reader. so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? Be easier if you read the Brook White paper and the patent from which most of the White paper is taken (the patent contains more about the detector bias) Not easier when Brook's not here. White paper http://www.tubecad.com/2007/12/15/Hi...20Amplifier%20... Put patent number * * 2361889 * * *into http://www.pat2pdf.org/ And download the PDF. Walsh discovered that if you sum the output tube currents (or voltage across a sense [pilot] resistor) *then the minimum seen is twice the idle current. That is trivially obvious when there's no audio but it's true even during Class AB or AB2. OK, thanks...the current summing of the two output valves is the bit I failed to take into account. Great disappointment, and too clever by half in my book. With a bit of tweeking, the summing isn't necessary, and a separate servo can be used for each valve, as I have described. Perhaps an extra 6SN7 would be too much to pay...a quad opamp and a couple of zeners is cheap but doesn't age. Forcing both output valves to the same bias voltage seems like a bad idea to me. These days, it's not too hard to program a microcontroller to set optimum bias, taking prevailing valve condition into account, and deal with fault conditions. Unfortunately, just as it gets cheap and easy in principle, it gets harder to manufacture because bits are so small and producing a pcb is an expensive pain in the neck. I still hope someone will answer my questions, but perhaps this wasn't the best place to come...it's just they fitted into a context here. Ian ( * Long before this discussion I had run simulations showing the waveforms and cobbled together a crude quickie SS version of the Brook Bias added to a 'balance servo' to see how they might interact http://flipperhome.dyndns.org/Full%2...ed%20Bias.htm* * * *) In the Brook the first 6SN7 is a 'peak' detector (which I substituted a transistor for), in this case negative peak, which captures those minimums and uses it to hold bias "like it's fixed' (through the feedback loop). Or you can view the tube as an AM "plate detector," which is the common usage, looking at the bottom modulation envelope of the 'audio carrier' (we're not demodulation audio, it's the 'carrier'. We're 'demodulating' idle current). It's a rather boring AM envelope because it's a 'flat line' representing idle current, hence I prefer to call it simply a (minimums) peak detector. http://en.wikipedia.org/wiki/Plate_detector_(radio) You'll probably have to copy and paste that link because (radio) is part of it but my reader insists it's not. Then, since he now has a means to "measure" idle current no matter what the tubes are doing he can use that to 'regulate' bias and hold it "essentially fixed" to the desired value regardless of static, Class A, or Class AB(2) operation. Patrick chooses to ignore the text, including the patent's explanation of how to bias the 6SN7, and insists it's nothing more than a triode 'amplifier' so bias will shift with the average DC on it's cathode, which would cause output bias shift during Class AB(2) just like would happen if you used plain old bypassed Rk bias on the output tubes. And for some unknown reason he has decided the inventor thought it nifty to waste a tube doing nothing more than a cap and resistor under the output cathodes would, plus calling him a 'liar'. "Trough detector" was Patrick substitution for the "minimums" and "peak detector" terminology. A problem with self-regulating bias is that asymmetric current in the ouput valves, particularly at high signal levels, contains a DC component that the regulator interprets as an increase in bias current. The regulator will tend to respond by reducing the bias current, thus making the asymmetry worse. Triode operation in particular produces predominantly 2H distortion, so a symmetrical input signal will always result in a DC component in the output, increasing with signal amplitude. In addition, in PP AB, asymmetry increases rapidly when the output stage is driven into class B. The result, as with ordinary cathode bias, is a bias current that always wanders and sometimes strays considerably. A crude and probably intrusive solution is to impose a fixed limit on the output voltage of the regulator. With cathode bias this could be done by connecting a zener accross the cathode capacitor. A potentially better solution is to condition the input to the regulator to remove the assymmetry. Ideally, a none- inverting amp with congruent distortion and clipping characteristics can be used for this purpose. Gain in the regulator circuit also allows for tighter control, resulting in fixed bias. It then makes more sense to apply the bias control voltage to the grid than to the low-impedance cathode. The posted circuit for the 10c doesn't show voltages, unfortunately, but it looks like an attempt at the perfect solution. If the triode in the current detector part of the circuit is set up right, then it should have equal distortion, and clip at the same point, but in the opposite direction, as the output valves. The output from the current detector then integrates to a constant DC value, which is used to determine the bias voltage. I wonder, as the control circuit valves age along with the output valves, whether they maintain the bias point in the same place relative to the characteristics of the output valves? That would solve a problem of fixed bias, which generally maintains a given current regardless of ageing, and so drifts in relation to valve characteristics. Morgan Jones in one of his books shows a comparatively crude SS version of the same circuit, using IIRC an opamp and a zener in place of the first triode in the Brook's control circuit, followed by the integrating LPF, and perhaps the other half of the opamp for the bias voltage output. Maybe discrete transistors instead of opamps...can't remember. The Butcher's combination of loose regulation and tight fixed limiting, with incompletely-bypassed SS in the signal path, looks like a bodge. Considering his amps are well specified for purpose (ie big enough), however, there is possibly enough headroom so the circuit is largely redundant, because it's set to allow some drift before doing its thing. To paraphrase Jim, from time long gone, if it's big enough, nothing else matters. On a related matter, while I'm passing, can anyone guide me to a clear definition of standard line level? I'm looking for an accepted standard for headroom. I have it in my head that a system should allow for 18dB above rms listening level. Tried looking but there's so much gobbledegook... To know how intrusive a limiter might be, either with the Butcher's bodge or my nascent headphone amp, it should strictly be necessary to know this. Also what kind of distribution, and what standard deviation, a piece of recorded music may have within that limit. The widespread use of compression in recording and broadcasting rather muddies the issue. I'd like to know the standard, rather than the common reality. Ian- Hide quoted text - - Show quoted text - |
|
#3
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
"Ian Iveson" wrote in message ... Flipper's posts disappear so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? A problem with self-regulating bias is that asymmetric current in the ouput valves, particularly at high signal levels, contains a DC component that the regulator interprets as an increase in bias current. The regulator will tend to respond by reducing the bias current, thus making the asymmetry worse. Triode operation in particular produces predominantly 2H distortion, so a symmetrical input signal will always result in a DC component in the output, increasing with signal amplitude. In addition, in PP AB, asymmetry increases rapidly when the output stage is driven into class B. The result, as with ordinary cathode bias, is a bias current that always wanders and sometimes strays considerably. Interestingly, the concept of Brook was (and is) so smart that even today certain people (including enlightened Patrick) can not grasp it. While the total average current from both cathodes changes and wanders greatly, the whole trick is that the minimae (troughs) of this current remain the same. The minimum remains the same at idle (at idle there are no troughs -- the current is stable) and at the loudest passages. Thus the whole idea is to control the bias voltage measuring the troughs, not the average. To measure the troughs you need the trough detector, not just an averaging DC amplifier. Trough detector servo system can always maintain a required target bias current regardless of the music content, load and +B voltage. In the days of Brook the implementation of the trough detector on a triode was not perfect as the cutt-off knee point in a triode 6SN7 is not perfectly sharp, but today, using Si diodes or transistors the trough detector system can be brought to perfection (if anyone cares, I do not). Regards, Alex |
|
#4
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Sat, 19 Nov 2011 13:46:52 -0800 (PST), Ian Iveson
wrote: On Nov 19, 8:20*pm, flipper wrote: On Sat, 19 Nov 2011 11:06:11 -0800 (PST), Ian Iveson wrote: Flipper's posts disappear Sorry. I suppose one of these days I should figure out where that setting hides in my news reader. so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? Be easier if you read the Brook White paper and the patent from which most of the White paper is taken (the patent contains more about the detector bias) Not easier when Brook's not here. I don't get it. What does "Brook's not here" have to do with reading documents? White paper http://www.tubecad.com/2007/12/15/Hi...20Amplifier%20... Put patent number * * 2361889 * * *into http://www.pat2pdf.org/ And download the PDF. Walsh discovered that if you sum the output tube currents (or voltage across a sense [pilot] resistor) *then the minimum seen is twice the idle current. That is trivially obvious when there's no audio but it's true even during Class AB or AB2. OK, thanks...the current summing of the two output valves is the bit I failed to take into account. Great disappointment, and too clever by half in my book. With a bit of tweeking, the summing isn't necessary, and a separate servo can be used for each valve, as I have described. Perhaps an extra 6SN7 would be too much to pay...a quad opamp and a couple of zeners is cheap but doesn't age. I don't see how your description below would work but, since I thought the question was how the Brook bias worked, I didn't put a lot of thought into it because, well, that's not how the Brook bias works. Forcing both output valves to the same bias voltage seems like a bad idea to me. Certainly not as good as balanced but, then, a single fixed bias wasn't unusual. The McIntosh, for example, is the same bias voltage for both tubes too. These days, it's not too hard to program a microcontroller to set optimum bias, taking prevailing valve condition into account, and deal with fault conditions. Unfortunately, just as it gets cheap and easy in principle, it gets harder to manufacture because bits are so small and producing a pcb is an expensive pain in the neck. I still hope someone will answer my questions, but perhaps this wasn't the best place to come...it's just they fitted into a context here. Sorry, I thought that was part of the other thing. Consumer line level is a bit fluid these days but the "analog" designation is 316mV (-10dBV) average program level with 16dB peak for 2Vrms. It's not so 'fixed' in the analog world since things like tape can take a few dB over before gross distortion sets in. The digital world confuses the matter because if, for example, you're using a 16 bit D/A then when it hits 65,535 there ain't no more. Brick wall, thump, ouch. As a result digital takes that as the 'reference point' (0dBfs) and specs it as "2Vfs" (fs=full scale). Usually they just say 2V. Average program level would then be -16dB(fs) except, since digital has a brick wall, they might go lower to ensure they're clear of it (say -18dBfs) or use tighter peak limiting/compression. It's essentially the same thing, though, with some digital 'gotchas' added. Or would be if it weren't for devices that can't handle 2Vrms out so you also have 1V(fs) and .5V(fs) devices, like cell phones and small MP3 players. Average program level is correspondingly lower, so they're not really 'consumer line level', but if you want to cater to them, like I did in the Gort transmitter, you need enough gain to handle it. Ian ( * Long before this discussion I had run simulations showing the waveforms and cobbled together a crude quickie SS version of the Brook Bias added to a 'balance servo' to see how they might interact http://flipperhome.dyndns.org/Full%2...ed%20Bias.htm* * * *) In the Brook the first 6SN7 is a 'peak' detector (which I substituted a transistor for), in this case negative peak, which captures those minimums and uses it to hold bias "like it's fixed' (through the feedback loop). Or you can view the tube as an AM "plate detector," which is the common usage, looking at the bottom modulation envelope of the 'audio carrier' (we're not demodulation audio, it's the 'carrier'. We're 'demodulating' idle current). It's a rather boring AM envelope because it's a 'flat line' representing idle current, hence I prefer to call it simply a (minimums) peak detector. http://en.wikipedia.org/wiki/Plate_detector_(radio) You'll probably have to copy and paste that link because (radio) is part of it but my reader insists it's not. Then, since he now has a means to "measure" idle current no matter what the tubes are doing he can use that to 'regulate' bias and hold it "essentially fixed" to the desired value regardless of static, Class A, or Class AB(2) operation. Patrick chooses to ignore the text, including the patent's explanation of how to bias the 6SN7, and insists it's nothing more than a triode 'amplifier' so bias will shift with the average DC on it's cathode, which would cause output bias shift during Class AB(2) just like would happen if you used plain old bypassed Rk bias on the output tubes. And for some unknown reason he has decided the inventor thought it nifty to waste a tube doing nothing more than a cap and resistor under the output cathodes would, plus calling him a 'liar'. "Trough detector" was Patrick substitution for the "minimums" and "peak detector" terminology. A problem with self-regulating bias is that asymmetric current in the ouput valves, particularly at high signal levels, contains a DC component that the regulator interprets as an increase in bias current. The regulator will tend to respond by reducing the bias current, thus making the asymmetry worse. Triode operation in particular produces predominantly 2H distortion, so a symmetrical input signal will always result in a DC component in the output, increasing with signal amplitude. In addition, in PP AB, asymmetry increases rapidly when the output stage is driven into class B. The result, as with ordinary cathode bias, is a bias current that always wanders and sometimes strays considerably. A crude and probably intrusive solution is to impose a fixed limit on the output voltage of the regulator. With cathode bias this could be done by connecting a zener accross the cathode capacitor. A potentially better solution is to condition the input to the regulator to remove the assymmetry. Ideally, a none- inverting amp with congruent distortion and clipping characteristics can be used for this purpose. Gain in the regulator circuit also allows for tighter control, resulting in fixed bias. It then makes more sense to apply the bias control voltage to the grid than to the low-impedance cathode. The posted circuit for the 10c doesn't show voltages, unfortunately, but it looks like an attempt at the perfect solution. If the triode in the current detector part of the circuit is set up right, then it should have equal distortion, and clip at the same point, but in the opposite direction, as the output valves. The output from the current detector then integrates to a constant DC value, which is used to determine the bias voltage. I wonder, as the control circuit valves age along with the output valves, whether they maintain the bias point in the same place relative to the characteristics of the output valves? That would solve a problem of fixed bias, which generally maintains a given current regardless of ageing, and so drifts in relation to valve characteristics. Morgan Jones in one of his books shows a comparatively crude SS version of the same circuit, using IIRC an opamp and a zener in place of the first triode in the Brook's control circuit, followed by the integrating LPF, and perhaps the other half of the opamp for the bias voltage output. Maybe discrete transistors instead of opamps...can't remember. The Butcher's combination of loose regulation and tight fixed limiting, with incompletely-bypassed SS in the signal path, looks like a bodge. Considering his amps are well specified for purpose (ie big enough), however, there is possibly enough headroom so the circuit is largely redundant, because it's set to allow some drift before doing its thing. To paraphrase Jim, from time long gone, if it's big enough, nothing else matters. On a related matter, while I'm passing, can anyone guide me to a clear definition of standard line level? I'm looking for an accepted standard for headroom. I have it in my head that a system should allow for 18dB above rms listening level. Tried looking but there's so much gobbledegook... To know how intrusive a limiter might be, either with the Butcher's bodge or my nascent headphone amp, it should strictly be necessary to know this. Also what kind of distribution, and what standard deviation, a piece of recorded music may have within that limit. The widespread use of compression in recording and broadcasting rather muddies the issue. I'd like to know the standard, rather than the common reality. Ian- Hide quoted text - - Show quoted text - |
|
#5
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
Note: The author of this message requested that it not be archived.
This message will be removed from Groups in 6 days (Nov 26, 2:20 pm). On Sat, 19 Nov 2011 11:06:11 -0800 (PST), Ian Iveson wrote: Flipper's posts disappear Sorry. I suppose one of these days I should figure out where that setting hides in my news reader. so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? Be easier if you read the Brook White paper and the patent from which most of the White paper is taken (the patent contains more about the detector bias) White paper http://www.tubecad.com/2007/12/15/Hi...20Amplifier%20... Put patent number 2361889 into http://www.pat2pdf.org/ And download the PDF. Walsh discovered that if you sum the output tube currents (or voltage across a sense [pilot] resistor) then the minimum seen is twice the idle current. That is trivially obvious when there's no audio but it's true even during Class AB or AB2. ( Long before this discussion I had run simulations showing the waveforms and cobbled together a crude quickie SS version of the Brook Bias added to a 'balance servo' to see how they might interact http://flipperhome.dyndns.org/Full%2...xed%20Bias.htm ) In the Brook the first 6SN7 is a 'peak' detector (which I substituted a transistor for), in this case negative peak, which captures those minimums and uses it to hold bias "like it's fixed' (through the feedback loop). Or you can view the tube as an AM "plate detector," which is the common usage, looking at the bottom modulation envelope of the 'audio carrier' (we're not demodulation audio, it's the 'carrier'. We're 'demodulating' idle current). It's a rather boring AM envelope because it's a 'flat line' representing idle current, hence I prefer to call it simply a (minimums) peak detector. http://en.wikipedia.org/wiki/Plate_detector_(radio) You'll probably have to copy and paste that link because (radio) is part of it but my reader insists it's not. Then, since he now has a means to "measure" idle current no matter what the tubes are doing he can use that to 'regulate' bias and hold it "essentially fixed" to the desired value regardless of static, Class A, or Class AB(2) operation. Patrick chooses to ignore the text, including the patent's explanation of how to bias the 6SN7, and insists it's nothing more than a triode 'amplifier' so bias will shift with the average DC on it's cathode, which would cause output bias shift during Class AB(2) just like would happen if you used plain old bypassed Rk bias on the output tubes. And for some unknown reason he has decided the inventor thought it nifty to waste a tube doing nothing more than a cap and resistor under the output cathodes would, plus calling him a 'liar'. "Trough detector" was Patrick substitution for the "minimums" and "peak detector" terminology. |
|
#6
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 20, 6:06*am, Ian Iveson wrote:
Flipper's posts disappear so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? A problem with self-regulating bias is that asymmetric current in the ouput valves, particularly at high signal levels, contains a DC component that the regulator interprets as an increase in bias current. The regulator will tend to respond by reducing the bias current, thus making the asymmetry worse. In other words, if Ek rises during class AB action, then Eg1 voltage is adjusted to be more negative thus reducing Ek, and usually you end up with a severely over biased pair of OP tubes, so you get a pile of crossover distortion, 3H and 5H etc. Such a scheme is bull****, and the answer is fixed bias, and no Rk, so Ek can't rise. But for control of the idle Ia, sure, some sort of Eg1 control is OK, except that if Ek rises, you get unwanted Eg1 corrections. Triode operation in particular produces predominantly 2H distortion, so a symmetrical input signal will always result in a DC component in the output, increasing with signal amplitude. In addition, in PP AB, asymmetry increases rapidly when the output stage is driven into class B. The result, as with ordinary cathode bias, is a bias current that always wanders and sometimes strays considerably. A crude and probably intrusive solution is to impose a fixed limit on the output voltage of the regulator. With cathode bias this could be done by connecting a zener accross the cathode capacitor. But to alow enough bias regulation with Rk, the zener voltage must be considerably higher value than the Idle Ek. But yes, at least it can be better than nothing in amps where its likely that Ek might rise a lot in AB use - some guitar amps perhaps. The use of zeners of the same value for say 2 OP tubes may mean that begin conducting at differing levels of Idc, so you get Idc imbalance. But for hi-fi, such schemes are not really worth chasing because average PO is so much lower than clipping levels. The bias wanderings one actually measures in most PP amps using AB cathode biased amps is fairly negligible if you have a high enough power ceiling. With 2 x KT88 UL, 50 Watts is possible, and not much bias wandering occurs, but with only 2 x 6BQ5, with the same speakers, not so. A potentially better solution is to condition the input to the regulator to remove the assymmetry. Ideally, a none- inverting amp with congruent distortion and clipping characteristics can be used for this purpose. ?????? Speaking in Riddles Again Ian? Gain in the regulator circuit also allows for tighter control, resulting in fixed bias. It then makes more sense to apply the bias control voltage to the grid than to the low-impedance cathode. The posted circuit for the 10c doesn't show voltages, unfortunately, but it looks like an attempt at the perfect solution. If the triode in the current detector part of the circuit is set up right, then it should have equal distortion, and clip at the same point, but in the opposite direction, as the output valves. The output from the current detector then integrates to a constant DC value, which is used to determine the bias voltage. I wonder, as the control circuit valves age along with the output valves, whether they maintain the bias point in the same place relative to the characteristics of the output valves? That would solve a problem of fixed bias, which generally maintains a given current regardless of ageing, and so drifts in relation to valve characteristics. The Brook appears to me to have a dc amp and a FB loop, so tube ageing probably won't affect much until ageing severely affects the tubes, ie, tubes run out of emission oand thus gain. But to know just how the Brook 10c really works ya have to build and measure a sample. Flipper is desperately trying to avoid doing the work which would make the brook 10C so clear to him. Years ago, You tried to avoid buying a copy of the Radiotron Designer's Handbook. People love to run about talking to every issue, posing as a know all, jarging the jargon, but unless ppl, read the books, build the circuits, they remain in the dark. Morgan Jones in one of his books shows a comparatively crude SS version of the same circuit, using IIRC an opamp and a zener in place of the first triode in the Brook's control circuit, followed by the integrating LPF, and perhaps the other half of the opamp for the bias voltage output. Maybe discrete transistors instead of opamps...can't remember. There have been a pile of circuits for active bias control. Some have worked to just keep Ek and hence Ik of each tube balanced eith a diff pair amp to adjust Eg1 bias, but not to react to overall Eg1 rise in AB action. None have survived the test of time. The Butcher's combination of loose regulation and tight fixed limiting, with incompletely-bypassed SS in the signal path, looks like a bodge. Can I assume you are referring to me as the Butcher? I guess so, typical, form a nincompoop like yourself, with such a tiny amount of experience building amps. Considering his amps are well specified for purpose (ie big enough), however, there is possibly enough headroom so the circuit is largely redundant, because it's set to allow some drift before doing its thing. To paraphrase Jim, from time long gone, if it's big enough, nothing else matters. Sometimes its handy to make a cathode biased amp behave as a fixed bias amp where the power wanted is fairly high compared to clipping power. My Dynamic Bias Stabilizer circuit would of course, to you, look like a Dynamic Butcher's Stabilizer, and you like nothing more to pour a bucket of **** on it if possible, because you hate me for pulling you down with a tackle everytime you makea silly run with a ball. Well, I really don't care, I've demonstarted to myself that my BDS bias scheme vastly reduces the amount of THD that would other wise occur with sine wave operation taken up to clipping in a class AB amp. People see those bjts I have in there and the gasp in horror; what a rotten horrid nasty man I am to do such a beastly thing! But youse ain't built and tested my circuit now have youse? So what the **** would you know about it? On a related matter, while I'm passing, can anyone guide me to a clear definition of standard line level? I'm looking for an accepted standard for headroom. I have it in my head that a system should allow for 18dB above rms listening level. Tried looking but there's so much gobbledegook... To know how intrusive a limiter might be, either with the Butcher's bodge or my nascent headphone amp, it should strictly be necessary to know this. Also what kind of distribution, and what standard deviation, a piece of recorded music may have within that limit. Ian, you get First Prize for speaking in un-decypherable riddles. What the heck has line levels go to do with DBS? The widespread use of compression in recording and broadcasting rather muddies the issue. I'd like to know the standard, rather than the common reality. Only a certain amount of adherence to standards exists. Line level used to mean, IHMO, and AFAIK, and I could be wrong, 200mV, and many power amps would clip with this level. Leak made their amps clip at 100mV, and Williamson needed 2Vrms, so 20dB above line level. Then came CD players and 200mV seems wrong now. I often make amps clip at between 0.5V and 2.0V input. So 0.5V can give 25Watts to the load, for a lowish power amp, say 25Watts at clip. For 250Watts, and to have the same sensitivity, ie, SPL for the same Vin, one would want 3.16 x 0.5Vrms input, or about 1.6Vrms. Line level is what's coming from the line, at whatever voltage, but unable to power speakers, as line impedance is 600 ohms. I don't worry about such matters much. But I am sure there's a pile of info Ian could read on line levels if he looked. Patrick Turner. Ian |
|
#7
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 20, 7:20*am, flipper wrote:
On Sat, 19 Nov 2011 11:06:11 -0800 (PST), Ian Iveson wrote: Flipper's posts disappear Sorry. I suppose one of these days I should figure out where that setting hides in my news reader. so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? Be easier if you read the Brook White paper and the patent from which most of the White paper is taken (the patent contains more about the detector bias) White paper http://www.tubecad.com/2007/12/15/Hi...20Amplifier%20... Put patent number * * 2361889 * * *into http://www.pat2pdf.org/ And download the PDF. Walsh discovered that if you sum the output tube currents (or voltage across a sense [pilot] resistor) *then the minimum seen is twice the idle current. That is trivially obvious when there's no audio but it's true even during Class AB or AB2. ( * Long before this discussion I had run simulations showing the waveforms and cobbled together a crude quickie SS version of the Brook Bias added to a 'balance servo' to see how they might interact http://flipperhome.dyndns.org/Full%2...ed%20Bias.htm* * * *) In the Brook the first 6SN7 is a 'peak' detector (which I substituted a transistor for), in this case negative peak, which captures those minimums and uses it to hold bias "like it's fixed' (through the feedback loop). Or you can view the tube as an AM "plate detector," which is the common usage, looking at the bottom modulation envelope of the 'audio carrier' (we're not demodulation audio, it's the 'carrier'. We're 'demodulating' idle current). It's a rather boring AM envelope because it's a 'flat line' representing idle current, hence I prefer to call it simply a (minimums) peak detector. http://en.wikipedia.org/wiki/Plate_detector_(radio) You'll probably have to copy and paste that link because (radio) is part of it but my reader insists it's not. Then, since he now has a means to "measure" idle current no matter what the tubes are doing he can use that to 'regulate' bias and hold it "essentially fixed" to the desired value regardless of static, Class A, or Class AB(2) operation. Patrick chooses to ignore the text, including the patent's explanation of how to bias the 6SN7, and insists it's nothing more than a triode 'amplifier' so bias will shift with the average DC on it's cathode, which would cause output bias shift during Class AB(2) just like would happen if you used plain old bypassed Rk bias on the output tubes. And for some unknown reason he has decided the inventor thought it nifty to waste a tube doing nothing more than a cap and resistor under the output cathodes would, plus calling him a 'liar'. "Trough detector" was Patrick substitution for the "minimums" and "peak detector" terminology. There is now a monumental pile of bull**** in all of what Flipper has said. He reckons he's right, but I can't see he is, and he's jarging the jargon, and taking the word of the lawyers who wrote the Brook patent and he's left no room at all in his mind for any doubt, and he won't solder a Brook together to discover exactly how it really works. No amount of typing crap at us to tell us all he's right just because he says he is will stop me saying he's a dumb idiot. I don't bother with all the details argued so far, Only Flipper has the time for such idiocy, rather than building the damn circuit to see how it really works. And it seems that because I suggest he build it, he's as stubborn as a mule, and just won't, lest he lose face, or discover something that might discredit what he's said so far. So, regardless of whether I'm right or wrong, it makes no difference, Flipper COULD be wrong, and he won't admit that this is possible, so his position is that of a dunce who thinks all the world is wrong, and that he never is, and that patent content is 100% correct. But just how many ppl really understand that patent? And I mean apart from those who say they understand, but don't. There's just complexity in the Brook 10C bias circuit to completely bamboozle most ppl. Its the kind of thing one can have endless arguments over terminology and interpretations, and so it all goes on so uselessly, with much ****ing in the wind, and braying into the wilderness. I reckon Fipper is bamboozled until he prooves otherwise - by building and measuring, not simulating and arguing. Of course I've never ever seen any other tube amp with a Brook 10C bias control circuit. Now I really have to wonder why this absense of Brook Ideas has existed for such a long time now. Maybe the idea ain't what its cracked up to be, and idea not worth copying, stealing, or buying. Maybe it does things that ya don't want to see happening in an amp. But hey, Flipper could find out easy enough, just STFU and knuckle down to an afternoon's soldering and all would be revealed. I spent all today soldering amps, and getting somewhere, some thoughts, calculations, some circuitry. What is stopping Flipper? Patrick Turner. |
|
#8
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 20, 11:49*am, "Alex Pogossov" wrote:
"Ian Iveson" wrote in message ... Flipper's posts disappear so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? A problem with self-regulating bias is that asymmetric current in the ouput valves, particularly at high signal levels, contains a DC component that the regulator interprets as an increase in bias current. The regulator will tend to respond by reducing the bias current, thus making the asymmetry worse. Triode operation in particular produces predominantly 2H distortion, so a symmetrical input signal will always result in a DC component in the output, increasing with signal amplitude. In addition, in PP AB, asymmetry increases rapidly when the output stage is driven into class B. The result, as with ordinary cathode bias, is a bias current that always wanders and sometimes strays considerably. Interestingly, the concept of Brook was (and is) so smart that even today certain people (including enlightened Patrick) can not grasp it. While the total average current from both cathodes changes and wanders greatly, the whole trick is that the minimae (troughs) of this current remain the same. The minimum remains the same at idle (at idle there are no troughs -- the current is stable) and at the loudest passages. Thus the whole idea is to control the bias voltage measuring the troughs, not the average. To measure the troughs you need the trough detector, not just an averaging DC amplifier. Trough detector servo system can always maintain a required target bias current regardless of the music content, load and +B voltage. In the days of Brook the implementation of the trough detector on a triode was not perfect as the cutt-off knee point in a triode 6SN7 is not perfectly sharp, but today, using Si diodes or transistors the trough detector system can be brought to perfection (if anyone cares, I do not). Regards, Alex- Hide quoted text - - Show quoted text - He's another one who has not built or measured a Brook 10C and who says I don't get it. Bravo, you get to be seen as an idiot like Flipper. No amount of talking about such things as a Brook 10C bias circuit will enlighten anyone. Patrick Turner. |
|
#9
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Sun, 20 Nov 2011 05:29:22 -0800 (PST), Patrick Turner
wrote: On Nov 20, 7:20*am, flipper wrote: On Sat, 19 Nov 2011 11:06:11 -0800 (PST), Ian Iveson wrote: Flipper's posts disappear Sorry. I suppose one of these days I should figure out where that setting hides in my news reader. so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? Be easier if you read the Brook White paper and the patent from which most of the White paper is taken (the patent contains more about the detector bias) White paper http://www.tubecad.com/2007/12/15/Hi...20Amplifier%20... Put patent number * * 2361889 * * *into http://www.pat2pdf.org/ And download the PDF. Walsh discovered that if you sum the output tube currents (or voltage across a sense [pilot] resistor) *then the minimum seen is twice the idle current. That is trivially obvious when there's no audio but it's true even during Class AB or AB2. ( * Long before this discussion I had run simulations showing the waveforms and cobbled together a crude quickie SS version of the Brook Bias added to a 'balance servo' to see how they might interact http://flipperhome.dyndns.org/Full%2...ed%20Bias.htm* * * *) In the Brook the first 6SN7 is a 'peak' detector (which I substituted a transistor for), in this case negative peak, which captures those minimums and uses it to hold bias "like it's fixed' (through the feedback loop). Or you can view the tube as an AM "plate detector," which is the common usage, looking at the bottom modulation envelope of the 'audio carrier' (we're not demodulation audio, it's the 'carrier'. We're 'demodulating' idle current). It's a rather boring AM envelope because it's a 'flat line' representing idle current, hence I prefer to call it simply a (minimums) peak detector. http://en.wikipedia.org/wiki/Plate_detector_(radio) You'll probably have to copy and paste that link because (radio) is part of it but my reader insists it's not. Then, since he now has a means to "measure" idle current no matter what the tubes are doing he can use that to 'regulate' bias and hold it "essentially fixed" to the desired value regardless of static, Class A, or Class AB(2) operation. Patrick chooses to ignore the text, including the patent's explanation of how to bias the 6SN7, and insists it's nothing more than a triode 'amplifier' so bias will shift with the average DC on it's cathode, which would cause output bias shift during Class AB(2) just like would happen if you used plain old bypassed Rk bias on the output tubes. And for some unknown reason he has decided the inventor thought it nifty to waste a tube doing nothing more than a cap and resistor under the output cathodes would, plus calling him a 'liar'. "Trough detector" was Patrick substitution for the "minimums" and "peak detector" terminology. There is now a monumental pile of bull**** in all of what Flipper has said. He reckons he's right, but I can't see he is, and he's jarging the jargon, and taking the word of the lawyers who wrote the Brook patent and he's left no room at all in his mind for any doubt, and he won't solder a Brook together to discover exactly how it really works. No amount of typing crap at us to tell us all he's right just because he says he is will stop me saying he's a dumb idiot. And there it is. 'Lord Turner', self appointed 'knower of all things' hath spoken and no evidence, reason, fact or truth shall contradict his 'holy word'. I don't bother with all the details argued so far, Of course not, because "all the details" contradict 'Lord Turner' and that is not allowed by 'Lord Turner', so it is summarily ignored. Only Flipper has the time for such idiocy, rather than building the damn circuit to see how it really works. And it seems that because I suggest he build it, he's as stubborn as a mule, and just won't, lest he lose face, or discover something that might discredit what he's said so far. So, regardless of whether I'm right or wrong, it makes no difference, Flipper COULD be wrong, and he won't admit that this is possible, so his position is that of a dunce who thinks all the world is wrong, and that he never is, and that patent content is 100% correct. But just how many ppl really understand that patent? And I mean apart from those who say they understand, but don't. Because 'Lord Turner', self proclaimed 'knower of all things', halth said it is false so anyone who understand it does not. There's just complexity in the Brook 10C bias circuit to completely bamboozle most ppl. Its the kind of thing one can have endless arguments over terminology and interpretations, and so it all goes on so uselessly, with much ****ing in the wind, and braying into the wilderness. I reckon Fipper is bamboozled until he prooves otherwise - by building and measuring, not simulating and arguing. 'Lord Turner' hath 'reckoned' and spoken the path to 'redemption'. Of course I've never ever seen any other tube amp with a Brook 10C bias control circuit. Now I really have to wonder why this absense of Brook Ideas has existed for such a long time now. Maybe the idea ain't what its cracked up to be, and idea not worth copying, stealing, or buying. Maybe it does things that ya don't want to see happening in an amp. But hey, Flipper could find out easy enough, just STFU and knuckle down to an afternoon's soldering and all would be revealed. I spent all today soldering amps, and getting somewhere, some thoughts, calculations, some circuitry. What is stopping Flipper? Flipper has no need because he understands what's written. What's stopping 'Lord Turner'? Patrick Turner. |
|
#10
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Sun, 20 Nov 2011 05:33:50 -0800 (PST), Patrick Turner
wrote: On Nov 20, 11:49*am, "Alex Pogossov" wrote: "Ian Iveson" wrote in message ... Flipper's posts disappear so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? A problem with self-regulating bias is that asymmetric current in the ouput valves, particularly at high signal levels, contains a DC component that the regulator interprets as an increase in bias current. The regulator will tend to respond by reducing the bias current, thus making the asymmetry worse. Triode operation in particular produces predominantly 2H distortion, so a symmetrical input signal will always result in a DC component in the output, increasing with signal amplitude. In addition, in PP AB, asymmetry increases rapidly when the output stage is driven into class B. The result, as with ordinary cathode bias, is a bias current that always wanders and sometimes strays considerably. Interestingly, the concept of Brook was (and is) so smart that even today certain people (including enlightened Patrick) can not grasp it. While the total average current from both cathodes changes and wanders greatly, the whole trick is that the minimae (troughs) of this current remain the same. The minimum remains the same at idle (at idle there are no troughs -- the current is stable) and at the loudest passages. Thus the whole idea is to control the bias voltage measuring the troughs, not the average. To measure the troughs you need the trough detector, not just an averaging DC amplifier. Trough detector servo system can always maintain a required target bias current regardless of the music content, load and +B voltage. In the days of Brook the implementation of the trough detector on a triode was not perfect as the cutt-off knee point in a triode 6SN7 is not perfectly sharp, but today, using Si diodes or transistors the trough detector system can be brought to perfection (if anyone cares, I do not). Regards, Alex- Hide quoted text - - Show quoted text - He's another one who has not built or measured a Brook 10C and who says I don't get it. Bravo, you get to be seen as an idiot like Flipper. The fate of all who speaketh what 'Lord Turner' hath deemed heresy. No amount of talking about such things as a Brook 10C bias circuit will enlighten anyone. Certainly not 'Lord Turner'. Patrick Turner. |
|
#11
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Sun, 20 Nov 2011 05:03:47 -0800 (PST), Patrick Turner
wrote: snip Line level is what's coming from the line, at whatever voltage, but unable to power speakers, as line impedance is 600 ohms. That is the historical *telephone* 'line' impedance, and the origins of 0 dBm defined as 1mW (what the "m" means) into 600 ohms, since that was the telephone line impedance, which then converts, by E=SQR(PR), to .775V for 0 dBu (note "u", not "m"). Telephone lines were concerned with power transfer, that is optimal with balanced impedances, but it has nothing to do with consumer audio amplifiers where one is concerned with voltage transfer and there is no fixed, 'matched', impedance, so power is undefined. For example, a tube amplifier might have 100k input impedance while a transistor device might have 10k inputs. It doesn't (much) matter, as long as the preceding (low impedance) device can drive the load (which might be problematic for a tube amp driving a solid sate one), because we're only concerned with voltage transfer. Since impedance is undefined power is undefined so there is no meaningful conversion from dBu (.775 V) or dBV (1 V) to dBm (1 mW). Nominal voltage level for "Professional Line Level" is +4 dBu for 1.228 V. For "Consumer Line Level" it's -10dBV for 316 mV. "Input impedance" is specified separately, per amplifier, and is unrelated to the voltage spec. Line outputs usually specify the "minimum" load impedance they can drive and still maintain the voltage and distortion specs. Note that "0 dBm" is power (1mW) and converts to a different voltage for different applications because the impedance is different. For example, RF is often dealing with 50 Ohm impedances so the same 1mW, but into 50 ohms, converts to 224 mV which, if you wanted it in dBu or dBV would take another conversion since that 224 mV is not the '0' reference for either of them. That, a different reference, is also what confuses people about +4 dBu and -10 dBV. I.E. -10 dBV is not "14 dB below" +4 dBu because the two are not referenced to the same '0' point. You have to first convert to a common reference and then calculate the dB. I.E. +4 dBu is 1.228 V, -10dBV is .316 V, and the ratio is 0.257. Converting that ratio to dB, -10 dBV is, then, 11.8 dB down from +4dBu. Or, by subtraction, we can say that -10dBV is -7.8 dBu, which we could also arrive at by straight calculating .316 V relative to .775 V, the '0' reference for dBu. The thing to remember is dB is the logarithm of a ratio and has no meaning unless you know what the reference point is, which is what those things tacked onto the end of dB are meant to illuminate. I.E. dBV dBu dBm dBfs. There is usually a 'reason' for the referenced picked (even if it's simply 'mathematically convenient'). In the digital audio world it's "full scale" because that's a brick wall. There are 'no more bits' and, so, that is a 'very important thing' to keep track of. All 'dB' will be 'minuses' below the brick wall. In the analog world, while there might be a nebulous point where distortion begins to set in, there is generally no 'brick wall' to pick. Instead, the 'reference' is that level which the ear perceives as 'average' program level, the point which comprises the bulk of what's 'heard'. There are then transient peaks above (plus dB) and 'quiet' passages below (minus dB) but '0 dB' is the 'normal level', a nebulous term to be sure but that is the 'art' of the audio engineer. I.E. picking levels that best accommodate transient peaks while keeping 'quiet' passages above the noise floor. All this means that 0 dBV is not 0 dBfs is not 0 VU (which, if I remember correctly, is, on tape machines, something like -8dB from the point where distortion hits 3%). Patrick Turner. Ian |
|
#12
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 20, 1:03*pm, Patrick Turner wrote:
On Nov 20, 6:06*am, Ian Iveson wrote: Flipper's posts disappear so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? A problem with self-regulating bias is that asymmetric current in the ouput valves, particularly at high signal levels, contains a DC component that the regulator interprets as an increase in bias current. The regulator will tend to respond by reducing the bias current, thus making the asymmetry worse. In other words, if Ek rises during class AB action, then Eg1 voltage is adjusted to be more negative thus reducing Ek, and usually you end up with a severely over biased pair of OP tubes, so you get a pile of crossover distortion, 3H and 5H etc. Such a scheme is bull****, and the answer is fixed bias, and no Rk, so Ek can't rise. But for control of the idle Ia, sure, some sort of Eg1 control is OK, except that if Ek rises, you get unwanted Eg1 corrections. Triode operation in particular produces predominantly 2H distortion, so a symmetrical input signal will always result in a DC component in the output, increasing with signal amplitude. In addition, in PP AB, asymmetry increases rapidly when the output stage is driven into class B. The result, as with ordinary cathode bias, is a bias current that always wanders and sometimes strays considerably. A crude and probably intrusive solution is to impose a fixed limit on the output voltage of the regulator. With cathode bias this could be done by connecting a zener accross the cathode capacitor. But to alow enough bias regulation with Rk, the zener voltage must be considerably higher value than the Idle Ek. But yes, at least it can be better than nothing in amps where its likely that Ek might rise a lot in AB use - some guitar amps perhaps. The use of zeners of the same value for say 2 OP tubes may mean that begin conducting at differing levels of Idc, so you get Idc imbalance. But for hi-fi, such schemes are not really worth chasing because average PO is so much lower than clipping levels. The bias wanderings one actually measures in most PP amps using AB cathode biased amps is fairly negligible if you have a high enough power ceiling. With 2 x KT88 UL, 50 Watts is possible, and not much bias wandering occurs, but with only 2 x 6BQ5, with the same speakers, not so. A potentially better solution is to condition the input to the regulator to remove the assymmetry. Ideally, a none- inverting amp with congruent distortion and clipping characteristics can be used for this purpose. ?????? Speaking in Riddles Again Ian? Not intentionally. Congruent in this case means the same shape. If you derive a voltage from a current sensing resistor at the cathode of an output valve, then it looks roughly like the second diagram down on the illustrations in the Brook ad posted by flipper. The signal comprises the DC bias level with asymmetric AC imposed upon it. If the output valve is cutting off, then this AC component will be cut off at zero and will rise beyond twice the bias level. Now, if you use a grounded grid triode to amplify this signal, set up so that it clips when its input is twice bias level, then it will clip the peaks but not the troughs. If the triode's characteristics are the same shape as the output valves, the peaks and troughs will be the same shape. Then, if you integrate the signal with a cap, you get a steady representation of the bias level which then serves as feedback to the grid control circuit. You could use a transistor and a zener for the circuit I have described, so it cuts off at the right point. But it won't have the same distortion, so it won't perfectly cancel so it doesn't have the same attractive elegance. Gain in the regulator circuit also allows for tighter control, resulting in fixed bias. It then makes more sense to apply the bias control voltage to the grid than to the low-impedance cathode. The posted circuit for the 10c doesn't show voltages, unfortunately, but it looks like an attempt at the perfect solution. If the triode in the current detector part of the circuit is set up right, then it should have equal distortion, and clip at the same point, but in the opposite direction, as the output valves. The output from the current detector then integrates to a constant DC value, which is used to determine the bias voltage. I wonder, as the control circuit valves age along with the output valves, whether they maintain the bias point in the same place relative to the characteristics of the output valves? That would solve a problem of fixed bias, which generally maintains a given current regardless of ageing, and so drifts in relation to valve characteristics. The Brook appears to me to have a dc amp and a FB loop, so tube ageing probably won't affect much until ageing severely affects the tubes, ie, tubes run out of emission oand thus gain. But to know just how the Brook 10c really works ya have to build and measure a sample. Flipper is desperately trying to avoid doing the work which would make the brook 10C so clear to him. Years ago, You tried to avoid buying a copy of the Radiotron Designer's Handbook. People love to run about talking to every issue, posing as a know all, jarging the jargon, but unless ppl, read the books, build the circuits, they remain in the dark. Morgan Jones in one of his books shows a comparatively crude SS version of the same circuit, using IIRC an opamp and a zener in place of the first triode in the Brook's control circuit, followed by the integrating LPF, and perhaps the other half of the opamp for the bias voltage output. Maybe discrete transistors instead of opamps...can't remember. There have been a pile of circuits for active bias control. Some have worked to just keep Ek and hence Ik of each tube balanced eith a diff pair amp to adjust Eg1 bias, but not to react to overall Eg1 rise in AB action. None have survived the test of time. You just make stuff up on the fly and don't read. The Brook that started all this fetched a fortune. The Butcher's combination of loose regulation and tight fixed limiting, with incompletely-bypassed SS in the signal path, looks like a bodge. Can I assume you are referring to me as the Butcher? I guess so, typical, form a nincompoop like yourself, with such a tiny amount of experience building amps. I know nearly everything in the universe, but made only a small part of it. You know bugger all. So far you have failed the Turing test. Considering his amps are well specified for purpose (ie big enough), however, there is possibly enough headroom so the circuit is largely redundant, because it's set to allow some drift before doing its thing. To paraphrase Jim, from time long gone, if it's big enough, nothing else matters. Sometimes its handy to make a cathode biased amp behave as a fixed bias amp where the power wanted is fairly high compared to clipping power. My Dynamic Bias Stabilizer circuit would of course, to you, look like a Dynamic Butcher's Stabilizer, and you like nothing more to pour a bucket of **** on it if possible, because you hate me for pulling you down with a tackle everytime you makea silly run with a ball. Well, I really don't care, I've demonstarted to myself that my BDS bias scheme vastly reduces the amount of THD that would other wise occur with sine wave operation taken up to clipping in a class AB amp. People see those bjts I have in there and the gasp in horror; what a rotten horrid nasty man I am to do such a beastly thing! But youse ain't built and tested my circuit now have youse? So what the **** would you know about it? On a related matter, while I'm passing, can anyone guide me to a clear definition of standard line level? I'm looking for an accepted standard for headroom. I have it in my head that a system should allow for 18dB above rms listening level. Tried looking but there's so much gobbledegook... To know how intrusive a limiter might be, either with the Butcher's bodge or my nascent headphone amp, it should strictly be necessary to know this. Also what kind of distribution, and what standard deviation, a piece of recorded music may have within that limit. Ian, you get First Prize for speaking in un-decypherable riddles. What the heck has line levels go to do with DBS. Relative amplitude, of course. Competent design of a device requires that its operating parameters are known and taken into account as far as possible. Your device intervenes at a "high" signal level, which happens "occasionally". Unless you know how high "high" is, how often high occurs, and whether highs come one at a time or in flurries, you don't know much about what your device is doing. You should do proper tests and publish them before you attempt to profit from your snake-oil. Ian The widespread use of compression in recording and broadcasting rather muddies the issue. I'd like to know the standard, rather than the common reality. Only a certain amount of adherence to standards exists. Line level used to mean, IHMO, and AFAIK, and I could be wrong, 200mV, and many power amps would clip with this level. Leak made their amps clip at 100mV, and Williamson needed 2Vrms, so 20dB above line level. Then came CD players and 200mV seems wrong now. I often make amps clip at between 0.5V and 2.0V input. So 0.5V can give 25Watts to the load, for a lowish power amp, say 25Watts at clip. For 250Watts, and to have the same sensitivity, ie, SPL for the same Vin, one would want 3.16 x 0.5Vrms input, or about 1.6Vrms. Line level is what's coming from the line, at whatever voltage, but unable to power speakers, as line impedance is 600 ohms. I don't worry about such matters much. But I am sure there's a pile of info Ian could read on line levels if he looked. Patrick Turner. Ian- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - |
|
#13
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 20, 10:44*pm, flipper wrote:
On Sun, 20 Nov 2011 05:03:47 -0800 (PST), Patrick Turner wrote: snip Line level is what's coming from the line, at whatever voltage, but unable to power speakers, as line impedance is 600 ohms. That is the historical *telephone* 'line' impedance, and the origins of 0 dBm defined as 1mW (what the "m" means) into 600 ohms, since that was the telephone line impedance, which then converts, by E=SQR(PR), to .775V for 0 dBu (note "u", not "m"). Telephone lines were concerned with power transfer, that is optimal with balanced impedances, but it has nothing to do with consumer audio amplifiers where one is concerned with voltage transfer and there is no fixed, 'matched', impedance, so power is undefined. For example, a tube amplifier might have 100k input impedance while a transistor device might have 10k inputs. It doesn't (much) matter, as long as the preceding (low impedance) device can drive the load (which might be problematic for a tube amp driving a solid sate one), because we're only concerned with voltage transfer. Since impedance is undefined power is undefined so there is no meaningful conversion from dBu (.775 V) or dBV (1 V) to dBm (1 mW). Nominal voltage level for "Professional Line Level" is +4 dBu for 1.228 V. For "Consumer Line Level" it's -10dBV for 316 mV. "Input impedance" is specified separately, per amplifier, and is unrelated to the voltage spec. Line outputs usually specify the "minimum" load impedance they can drive and still maintain the voltage and distortion specs. Note that "0 dBm" is power (1mW) and converts to a different voltage for different applications because the impedance is different. For example, RF is often dealing with 50 Ohm impedances so the same 1mW, but into 50 ohms, converts to 224 mV which, if you wanted it in dBu or dBV would take another conversion since that 224 mV is not the '0' reference for either of them. That, a different reference, is also what confuses people about +4 dBu and -10 dBV. I.E. -10 dBV is not "14 dB below" +4 dBu because the two are not referenced to the same '0' point. You have to first convert to a common reference and then calculate the dB. I.E. +4 dBu is 1.228 V, -10dBV is .316 V, and the ratio is 0.257. Converting that ratio to dB, -10 dBV is, then, 11.8 dB down from +4dBu. Or, by subtraction, we can say that -10dBV is -7.8 dBu, which we could also arrive at by straight calculating .316 V relative to .775 V, the '0' reference for dBu. The thing to remember is dB is the logarithm of a ratio and has no meaning unless you know what the reference point is, which is what those things tacked onto the end of dB are meant to illuminate. I.E. dBV dBu dBm dBfs. No! The crucial thing to remember is that a dB is about power and has no lack of meaning all alone. It is the log of a ratio of powers. What would you write if the reference were 1 Watt? When I see "-3dB @ 20kHz", should I be bamboozled because no reference point is given? If you think of dB as log of a ratio of Watts, then you can work all the others out and everything makes sense. For dBu you need also to know the reference terminating resistance, which I believe is 600 ohms. This is a common argument so I'm just running up the flag for the other side. You may say the Watts cancel out in the ratio, but I argue like a true dialectical materialist: their history remains. There is usually a 'reason' for the referenced picked (even if it's simply 'mathematically convenient'). In the digital audio world it's "full scale" because that's a brick wall. There are 'no more bits' and, so, that is a 'very important thing' to keep track of. All 'dB' will be 'minuses' below the brick wall. In the analog world, while there might be a nebulous point where distortion begins to set in, there is generally no 'brick wall' to pick. Instead, the 'reference' is that level which the ear perceives as 'average' program level, the point which comprises the bulk of what's 'heard'. There are then transient peaks above (plus dB) and 'quiet' passages below (minus dB) but '0 dB' is the 'normal level', a nebulous term to be sure but that is the 'art' of the audio engineer. I.E. picking levels that best accommodate transient peaks while keeping 'quiet' passages above the noise floor. All this means that 0 dBV is not 0 dBfs is not 0 VU (which, if I remember correctly, is, on tape machines, something like -8dB from the point where distortion hits 3%). Patrick Turner. Ian- Hide quoted text - - Show quoted text - |
|
#14
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Sun, 20 Nov 2011 17:07:51 -0800 (PST), Ian Iveson
wrote: On Nov 20, 10:44*pm, flipper wrote: On Sun, 20 Nov 2011 05:03:47 -0800 (PST), Patrick Turner wrote: snip Line level is what's coming from the line, at whatever voltage, but unable to power speakers, as line impedance is 600 ohms. That is the historical *telephone* 'line' impedance, and the origins of 0 dBm defined as 1mW (what the "m" means) into 600 ohms, since that was the telephone line impedance, which then converts, by E=SQR(PR), to .775V for 0 dBu (note "u", not "m"). Telephone lines were concerned with power transfer, that is optimal with balanced impedances, but it has nothing to do with consumer audio amplifiers where one is concerned with voltage transfer and there is no fixed, 'matched', impedance, so power is undefined. For example, a tube amplifier might have 100k input impedance while a transistor device might have 10k inputs. It doesn't (much) matter, as long as the preceding (low impedance) device can drive the load (which might be problematic for a tube amp driving a solid sate one), because we're only concerned with voltage transfer. Since impedance is undefined power is undefined so there is no meaningful conversion from dBu (.775 V) or dBV (1 V) to dBm (1 mW). Nominal voltage level for "Professional Line Level" is +4 dBu for 1.228 V. For "Consumer Line Level" it's -10dBV for 316 mV. "Input impedance" is specified separately, per amplifier, and is unrelated to the voltage spec. Line outputs usually specify the "minimum" load impedance they can drive and still maintain the voltage and distortion specs. Note that "0 dBm" is power (1mW) and converts to a different voltage for different applications because the impedance is different. For example, RF is often dealing with 50 Ohm impedances so the same 1mW, but into 50 ohms, converts to 224 mV which, if you wanted it in dBu or dBV would take another conversion since that 224 mV is not the '0' reference for either of them. That, a different reference, is also what confuses people about +4 dBu and -10 dBV. I.E. -10 dBV is not "14 dB below" +4 dBu because the two are not referenced to the same '0' point. You have to first convert to a common reference and then calculate the dB. I.E. +4 dBu is 1.228 V, -10dBV is .316 V, and the ratio is 0.257. Converting that ratio to dB, -10 dBV is, then, 11.8 dB down from +4dBu. Or, by subtraction, we can say that -10dBV is -7.8 dBu, which we could also arrive at by straight calculating .316 V relative to .775 V, the '0' reference for dBu. The thing to remember is dB is the logarithm of a ratio and has no meaning unless you know what the reference point is, which is what those things tacked onto the end of dB are meant to illuminate. I.E. dBV dBu dBm dBfs. No! The crucial thing to remember is that a dB is about power and has no lack of meaning all alone. It is the log of a ratio of powers. You're going to have a heck of a time with dBu and dBV. When someone tells you a tone stack has 16dB boost at 15kHz just what impedance is the driving stage reference and the output impedance of the tone stack? And how does them being different affect the dB 'power ratio'? The conventional answer is you don't care and it doesn't because you're speaking of a voltage ratio, namely Vout/Vin. What would you write if the reference were 1 Watt? Conveniently that's dBW. When I see "-3dB @ 20kHz", should I be bamboozled because no reference point is given? Well, then explain to me -3dB of WHAT? Or are you presuming a reference point of the power at 1kHz, which is a common specification for audio power amplifier frequency response? You're not ' bamboozled' because you know what the 'common usage' is, the 'understood' reference, but a Martian who just landed would be. Or maybe you *are* 'bamboozled' because, is that the output voltage spec of a preamp, or the output watts of a power amp, or something else? If you think of dB as log of a ratio of Watts, then you can work all the others out and everything makes sense. You can't 'work out' dBV from power because impedance is undefined. For dBu you need also to know the reference terminating resistance, which I believe is 600 ohms. That's dBm. dBu is the 'unspecified' impedance 'equivalent', which is the very reason it came into being. You don't need 'another one' for the same thing. Professional Line Level isn't operating at 600 Ohms so what would +4dBu mean with your presumption of 'power'? Let's say we have a preamp putting out -10dBV (consumer line level) and we have both a tube amplifier with 100k inputs and a solid state amplifier with 10k inputs. Okay, which one is 'not seeing' -10dBV? Or is it both and what would I need for -10dBV? This is a common argument so I'm just running up the flag for the other side. You may say the Watts cancel out in the ratio, but I argue like a true dialectical materialist: their history remains. I'll stick with mathematics since there's a few thousand years of experience saying 'it works'. When dealing with power the equation is 10Log(A1/A2) When dealing with voltage the equation is 20Log(A1/A2) The 2x, or .5x, depending on which side you prefer, captures the ^2 in the P=E^2/R relationship. There is usually a 'reason' for the referenced picked (even if it's simply 'mathematically convenient'). In the digital audio world it's "full scale" because that's a brick wall. There are 'no more bits' and, so, that is a 'very important thing' to keep track of. All 'dB' will be 'minuses' below the brick wall. In the analog world, while there might be a nebulous point where distortion begins to set in, there is generally no 'brick wall' to pick. Instead, the 'reference' is that level which the ear perceives as 'average' program level, the point which comprises the bulk of what's 'heard'. There are then transient peaks above (plus dB) and 'quiet' passages below (minus dB) but '0 dB' is the 'normal level', a nebulous term to be sure but that is the 'art' of the audio engineer. I.E. picking levels that best accommodate transient peaks while keeping 'quiet' passages above the noise floor. All this means that 0 dBV is not 0 dBfs is not 0 VU (which, if I remember correctly, is, on tape machines, something like -8dB from the point where distortion hits 3%). Patrick Turner. Ian- Hide quoted text - - Show quoted text - |
|
#15
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 21, 3:43*am, flipper wrote:
On Sun, 20 Nov 2011 17:07:51 -0800 (PST), Ian Iveson wrote: On Nov 20, 10:44*pm, flipper wrote: On Sun, 20 Nov 2011 05:03:47 -0800 (PST), Patrick Turner wrote: snip Line level is what's coming from the line, at whatever voltage, but unable to power speakers, as line impedance is 600 ohms. That is the historical *telephone* 'line' impedance, and the origins of 0 dBm defined as 1mW (what the "m" means) into 600 ohms, since that was the telephone line impedance, which then converts, by E=SQR(PR), to .775V for 0 dBu (note "u", not "m"). Telephone lines were concerned with power transfer, that is optimal with balanced impedances, but it has nothing to do with consumer audio amplifiers where one is concerned with voltage transfer and there is no fixed, 'matched', impedance, so power is undefined. For example, a tube amplifier might have 100k input impedance while a transistor device might have 10k inputs. It doesn't (much) matter, as long as the preceding (low impedance) device can drive the load (which might be problematic for a tube amp driving a solid sate one), because we're only concerned with voltage transfer. Since impedance is undefined power is undefined so there is no meaningful conversion from dBu (.775 V) or dBV (1 V) to dBm (1 mW). Nominal voltage level for "Professional Line Level" is +4 dBu for 1.228 V. For "Consumer Line Level" it's -10dBV for 316 mV. "Input impedance" is specified separately, per amplifier, and is unrelated to the voltage spec. Line outputs usually specify the "minimum" load impedance they can drive and still maintain the voltage and distortion specs. Note that "0 dBm" is power (1mW) and converts to a different voltage for different applications because the impedance is different. For example, RF is often dealing with 50 Ohm impedances so the same 1mW, but into 50 ohms, converts to 224 mV which, if you wanted it in dBu or dBV would take another conversion since that 224 mV is not the '0' reference for either of them. That, a different reference, is also what confuses people about +4 dBu and -10 dBV. I.E. -10 dBV is not "14 dB below" +4 dBu because the two are not referenced to the same '0' point. You have to first convert to a common reference and then calculate the dB. I.E. +4 dBu is 1.228 V, -10dBV is .316 V, and the ratio is 0.257. Converting that ratio to dB, -10 dBV is, then, 11.8 dB down from +4dBu. Or, by subtraction, we can say that -10dBV is -7.8 dBu, which we could also arrive at by straight calculating .316 V relative to .775 V, the '0' reference for dBu. The thing to remember is dB is the logarithm of a ratio and has no meaning unless you know what the reference point is, which is what those things tacked onto the end of dB are meant to illuminate. I.E. dBV dBu dBm dBfs. No! The crucial thing to remember is that a dB is about power and has no lack of meaning all alone. It is the log of a ratio of powers. You're going to have a heck of a time with dBu and dBV. Easy if you know dB is about power. When someone tells you a tone stack has 16dB boost at 15kHz just what impedance is the driving stage reference and the output impedance of the tone stack? And how does them being different affect the dB 'power ratio'? Doesn't matter. Your confusing yourself. The conventional answer is you don't care and it doesn't because you're speaking of a voltage ratio, namely Vout/Vin. Because I know that dB is about power, I can work all that out for myself. If I didn't know it was about power, I couldn't, because it wouldn't make sense. Double the voltage will be +6dBV, for example, because it would result in four times the power, whatever the value of the constant resistance. Having said that, I sometimes have to think, and sometimes need to check I haven't got the relationship backwards. What would you write if the reference were 1 Watt? Conveniently that's dBW. I agree, which leads folk to wonder what happened to the "W" in dBm. When I see "-3dB @ 20kHz", should I be bamboozled because no reference point is given? Well, then explain to me -3dB of WHAT? Half the power at midband. As long as I know it's a ratio of power, it makes sense. Or are you presuming a reference point of the power at 1kHz, which is a common specification for audio power amplifier frequency response? I assume midband, and wonder where midband might be defined to be. For audio I would assume 1kHz, small signal, unless otherwise stated. The crucial point is that we know it is a ratio of power. The reference level may or may not matter, depending on the situation. You're not ' bamboozled' because you know what the 'common usage' is, the 'understood' reference, but a Martian who just landed would be. Don't be daft. Don't they have Wikipedia on Mars? An uninformed Martian would be bamboozled however the dB were defined. Or maybe you *are* 'bamboozled' because, is that the output voltage spec of a preamp, or the output watts of a power amp, or something else? It doesn't matter. -3dB is always half power. If you think of dB as log of a ratio of Watts, then you can work all the others out and everything makes sense. You can't 'work out' dBV from power because impedance is undefined. Yes you can, as you point out below. If you know that half power is -3dB, it follows that half voltage is -6dB, being quarter power, because power is proportional to the square of voltage, and log square is double. For dBu you need also to know the reference terminating resistance, which I believe is 600 ohms. That's dBm. dBu is the 'unspecified' impedance 'equivalent', which is the very reason it came into being. You don't need 'another one' for the same thing. dBu "came into being" because it is referenced to the voltage required to produce 1mW into 600ohms. If I know the 600, I can work out the 0.775 Professional Line Level isn't operating at 600 Ohms so what would +4dBu mean with your presumption of 'power'? Its the voltage that would result in +4dB relative to the power produced by 1mV into 600ohms. Let's say we have a preamp putting out -10dBV (consumer line level) and we have both a tube amplifier with 100k inputs and a solid state amplifier with 10k inputs. Okay, which one is 'not seeing' -10dBV? Or is it both and what would I need for -10dBV? -10dBV is a voltage. It is the voltage reduction that would result in a 10dB fall in power. Your question doesn't make sense. This is a common argument so I'm just running up the flag for the other side. You may say the Watts cancel out in the ratio, but I argue like a true dialectical materialist: their history remains. I'll stick with mathematics since there's a few thousand years of experience saying 'it works'. We can both do maths at this level, I trust. I wouldn't advise sticking to maths exclusively though...there's more to language, and the world, than logic. When dealing with power the equation is 10Log(A1/A2) When dealing with voltage the equation is 20Log(A1/A2) The 2x, or .5x, depending on which side you prefer, captures the ^2 in the P=E^2/R relationship. 2x, please. .5x would be a silly contrivance. Maths alone won't tell you that. 2x, because log of a square is double. By convention, not by maths, dB is the log of a ratio of power. If you know that, and 600ohms... oh and 75ohms for the dBmV and a few other odds and sods, I see, now I've looked it up, you can work the others out. Ian There is usually a 'reason' for the referenced picked (even if it's simply 'mathematically convenient'). In the digital audio world it's "full scale" because that's a brick wall. There are 'no more bits' and, so, that is a 'very important thing' to keep track of. All 'dB' will be 'minuses' below the brick wall. In the analog world, while there might be a nebulous point where distortion begins to set in, there is generally no 'brick wall' to pick. Instead, the 'reference' is that level which the ear perceives as 'average' program level, the point which comprises the bulk of what's 'heard'. There are then transient peaks above (plus dB) and 'quiet' passages below (minus dB) but '0 dB' is the 'normal level', a nebulous term to be sure but that is the 'art' of the audio engineer. I.E. picking levels that best accommodate transient peaks while keeping 'quiet' passages above the noise floor. All this means that 0 dBV is not 0 dBfs is not 0 VU (which, if I remember correctly, is, on tape machines, something like -8dB from the point where distortion hits 3%). Patrick Turner. Ian- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - |
|
#16
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 21, 3:11*pm, Ian Iveson wrote:
"Double the voltage will be +6dBV, for example, because it would result in four times the power..." Unhappy with this. To my mind, dBu, dbV, et al are absolute, rather than relative levels. So, an increase in voltage from 1dBV to 6dBV would be a rise of 6dB, not 6dBV. Tricky though...seems a close call to me. I would be interested to know how you...anyone...would label the vertical axis of a graph showing amplitude v frequency. dBV? Or V (dB)? Or something else? The basic truth here is very simple but conventions often, perhaps invariably, lead to quirks and anomolies. Bits get added on the fly, and odd shorthands can enter mainstream usage. My background is not in electronics, so the dB was never drummed into my head. I speak from experience when I say that the newcomer's best guide is this: ***The dB is about power*** Very rarely have I needed to know the whole definition. If you remember that each +3dB is double the power, and each -3dB is half the power, guessterpolation works close enough. If I get lost I look it up. I know where to look, and how to make sense of what I find, because I know that: ***The dB is about power*** You are right, btw, to point out that power is not necessarily measured in Watts. Also, if I found a box with "-3dB" written on it, I might have very little clue as to what's inside. That, however, doesn't mean that "-3dB" is meaningless. If I'd already opened a similar box with no label at all, I could infer the meaning from its contents, as long as I remember that: ***The dB is about power*** I suspect that I, and everyone else, ought to acquaint ourselves with Wittgenstein. Don't get lost in semantics. Ian |
|
#17
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 20, 12:49*am, "Alex Pogossov" wrote:
"Ian Iveson" wrote in message ... Flipper's posts disappear so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? A problem with self-regulating bias is that asymmetric current in the ouput valves, particularly at high signal levels, contains a DC component that the regulator interprets as an increase in bias current. The regulator will tend to respond by reducing the bias current, thus making the asymmetry worse. Triode operation in particular produces predominantly 2H distortion, so a symmetrical input signal will always result in a DC component in the output, increasing with signal amplitude. In addition, in PP AB, asymmetry increases rapidly when the output stage is driven into class B. The result, as with ordinary cathode bias, is a bias current that always wanders and sometimes strays considerably. Interestingly, the concept of Brook was (and is) so smart that even today certain people (including enlightened Patrick) can not grasp it. While the total average current from both cathodes changes and wanders greatly, the whole trick is that the minimae (troughs) of this current remain the same. The minimum remains the same at idle (at idle there are no troughs -- the current is stable) and at the loudest passages. Thus the whole idea is to control the bias voltage measuring the troughs, not the average. To measure the troughs you need the trough detector, not just an averaging DC amplifier. Trough detector servo system can always maintain a required target bias current regardless of the music content, load and +B voltage. In the days of Brook the implementation of the trough detector on a triode was not perfect as the cutt-off knee point in a triode 6SN7 is not perfectly sharp, but today, using Si diodes or transistors the trough detector system can be brought to perfection (if anyone cares, I do not). Regards, Alex- Hide quoted text - - Show quoted text - Thanks, Alex. I wrote a reply but I'm not used to the google groups presentation and lost it without realising. I have since discovered in my head that my idea isn't perfect, because the signal conditioning triode won't chop the upswings to match the downswings. Its input is already distorted. May as well use SS. Do I care? Only in so far as I quite like thinking. Right thoughts are of no value, so I strive to propagate as many wrong thoughts as possible before breakfast, and spend the rest of the day sorting out the mess. If I were to automate my bias, I would replicate the occasional process of thorough manual optimisation that my amps currently enjoy. Ian |
|
#18
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Mon, 21 Nov 2011 13:50:10 -0800 (PST), Ian Iveson
wrote: On Nov 20, 12:49*am, "Alex Pogossov" wrote: "Ian Iveson" wrote in message ... Flipper's posts disappear so the 10c thread looks like David and Goliath, with Alex facing up to the ranting Butcher all alone. Comical but hard to follow. I guess a clue lies in the term "trough detector", but I can't imagine what that means. So, Alex and Flipper. Can you tell me if I've got this right? A problem with self-regulating bias is that asymmetric current in the ouput valves, particularly at high signal levels, contains a DC component that the regulator interprets as an increase in bias current. The regulator will tend to respond by reducing the bias current, thus making the asymmetry worse. Triode operation in particular produces predominantly 2H distortion, so a symmetrical input signal will always result in a DC component in the output, increasing with signal amplitude. In addition, in PP AB, asymmetry increases rapidly when the output stage is driven into class B. The result, as with ordinary cathode bias, is a bias current that always wanders and sometimes strays considerably. Interestingly, the concept of Brook was (and is) so smart that even today certain people (including enlightened Patrick) can not grasp it. While the total average current from both cathodes changes and wanders greatly, the whole trick is that the minimae (troughs) of this current remain the same. The minimum remains the same at idle (at idle there are no troughs -- the current is stable) and at the loudest passages. Thus the whole idea is to control the bias voltage measuring the troughs, not the average. To measure the troughs you need the trough detector, not just an averaging DC amplifier. Trough detector servo system can always maintain a required target bias current regardless of the music content, load and +B voltage. In the days of Brook the implementation of the trough detector on a triode was not perfect as the cutt-off knee point in a triode 6SN7 is not perfectly sharp, but today, using Si diodes or transistors the trough detector system can be brought to perfection (if anyone cares, I do not). Regards, Alex- Hide quoted text - - Show quoted text - Thanks, Alex. I wrote a reply but I'm not used to the google groups presentation and lost it without realising. I have since discovered in my head that my idea isn't perfect, because the signal conditioning triode won't chop the upswings to match the downswings. Its input is already distorted. May as well use SS. Do I care? Only in so far as I quite like thinking. Right thoughts are of no value, so I strive to propagate as many wrong thoughts as possible before breakfast, and spend the rest of the day sorting out the mess. Well, thank you for explaining your purpose is to come up with 'wrong thoughts' but, personally, I don't have the time to waste rehashing all the 'wrong thoughts' of history. If I were to automate my bias, I would replicate the occasional process of thorough manual optimisation that my amps currently enjoy. Ian |
|
#19
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Mon, 21 Nov 2011 07:11:42 -0800 (PST), Ian Iveson
wrote: On Nov 21, 3:43*am, flipper wrote: On Sun, 20 Nov 2011 17:07:51 -0800 (PST), Ian Iveson wrote: On Nov 20, 10:44*pm, flipper wrote: On Sun, 20 Nov 2011 05:03:47 -0800 (PST), Patrick Turner wrote: snip Line level is what's coming from the line, at whatever voltage, but unable to power speakers, as line impedance is 600 ohms. That is the historical *telephone* 'line' impedance, and the origins of 0 dBm defined as 1mW (what the "m" means) into 600 ohms, since that was the telephone line impedance, which then converts, by E=SQR(PR), to .775V for 0 dBu (note "u", not "m"). Telephone lines were concerned with power transfer, that is optimal with balanced impedances, but it has nothing to do with consumer audio amplifiers where one is concerned with voltage transfer and there is no fixed, 'matched', impedance, so power is undefined. For example, a tube amplifier might have 100k input impedance while a transistor device might have 10k inputs. It doesn't (much) matter, as long as the preceding (low impedance) device can drive the load (which might be problematic for a tube amp driving a solid sate one), because we're only concerned with voltage transfer. Since impedance is undefined power is undefined so there is no meaningful conversion from dBu (.775 V) or dBV (1 V) to dBm (1 mW). Nominal voltage level for "Professional Line Level" is +4 dBu for 1.228 V. For "Consumer Line Level" it's -10dBV for 316 mV. "Input impedance" is specified separately, per amplifier, and is unrelated to the voltage spec. Line outputs usually specify the "minimum" load impedance they can drive and still maintain the voltage and distortion specs. Note that "0 dBm" is power (1mW) and converts to a different voltage for different applications because the impedance is different. For example, RF is often dealing with 50 Ohm impedances so the same 1mW, but into 50 ohms, converts to 224 mV which, if you wanted it in dBu or dBV would take another conversion since that 224 mV is not the '0' reference for either of them. That, a different reference, is also what confuses people about +4 dBu and -10 dBV. I.E. -10 dBV is not "14 dB below" +4 dBu because the two are not referenced to the same '0' point. You have to first convert to a common reference and then calculate the dB. I.E. +4 dBu is 1.228 V, -10dBV is .316 V, and the ratio is 0.257. Converting that ratio to dB, -10 dBV is, then, 11.8 dB down from +4dBu. Or, by subtraction, we can say that -10dBV is -7.8 dBu, which we could also arrive at by straight calculating .316 V relative to .775 V, the '0' reference for dBu. The thing to remember is dB is the logarithm of a ratio and has no meaning unless you know what the reference point is, which is what those things tacked onto the end of dB are meant to illuminate. I.E. dBV dBu dBm dBfs. No! The crucial thing to remember is that a dB is about power and has no lack of meaning all alone. It is the log of a ratio of powers. You're going to have a heck of a time with dBu and dBV. Easy if you know dB is about power. Both dbu and dBV are defined as voltage ratios. Voltage is not power. When someone tells you a tone stack has 16dB boost at 15kHz just what impedance is the driving stage reference and the output impedance of the tone stack? And how does them being different affect the dB 'power ratio'? Doesn't matter. Your confusing yourself. No, I'm not confused. I'm showing one would be confused if they tried your 'power' presumption. The conventional answer is you don't care and it doesn't because you're speaking of a voltage ratio, namely Vout/Vin. Because I know that dB is about power, Voltage is not power. I can work all that out for myself. So show me. What 'power' is 1V? If I didn't know it was about power, I couldn't, because it wouldn't make sense. Then I'll show you. dBV is defined as 20Log(A1/A2) with A2=1V, the reference voltage, so a 1V signal is 0dBV and a 10V signal is 20dB. Double the voltage will be +6dBV, The equation says so, yes. for example, because it would result in four times the power, Voltage is not power and there is no way to get power from dBV because there is no current, or load to derive it from, defined. whatever the value of the constant resistance. And I showed in the tone stack example there is no 'constant resistance'. Having said that, I sometimes have to think, and sometimes need to check I haven't got the relationship backwards. What would you write if the reference were 1 Watt? Conveniently that's dBW. I agree, which leads folk to wonder what happened to the "W" in dBm. Same thing that happened to the "eci' and the "el" in "dB." dBmW *is* sometimes used but what 'waste' the keystroke? When I see "-3dB @ 20kHz", should I be bamboozled because no reference point is given? Well, then explain to me -3dB of WHAT? Half the power at midband. As long as I know it's a ratio of power, it makes sense. You simply repeated my point in showing you know, or think you know, what the defined reference is. Without that it has, as I said, no meaning. Or are you presuming a reference point of the power at 1kHz, which is a common specification for audio power amplifier frequency response? I assume midband, and wonder where midband might be defined to be. For audio I would assume 1kHz, small signal, unless otherwise stated. Why? An earlier convention was 400Hz. The crucial point is that we know it is a ratio of power. No, the crucial point is you know the reference. The reference level may or may not matter, depending on the situation. It's precisely what matters and, for example, you have no idea what power '-3dB' is unless you presume the 'response' being talked about is power, as opposed to a preamp voltage output (or something else), and is the commonly used 1 Watt reference in power amplifier specs. You're not ' bamboozled' because you know what the 'common usage' is, the 'understood' reference, but a Martian who just landed would be. Don't be daft. Don't they have Wikipedia on Mars? Funny but it doesn't change the allegory. An uninformed Martian would be bamboozled however the dB were defined. Not if he can read. But you can't read "presumptions'. Or maybe you *are* 'bamboozled' because, is that the output voltage spec of a preamp, or the output watts of a power amp, or something else? It doesn't matter. -3dB is always half power. Voltage is not power. What is the 'power' of a preamp's 316mV output? You have no idea but I do know it's 0 dBV. If you think of dB as log of a ratio of Watts, then you can work all the others out and everything makes sense. You can't 'work out' dBV from power because impedance is undefined. Yes you can, as you point out below. No you can't and the equations I gave below do not translate voltage across an unspecified load to power either. P=E/? is not defined. If you know that half power is -3dB, it follows that half voltage is -6dB, being quarter power, It 'follows' only if you have a known load from which to derive power. because power is proportional to the square of voltage, and log square is double. Correct. Now tell me how you derive power from V with no R. For dBu you need also to know the reference terminating resistance, which I believe is 600 ohms. That's dBm. dBu is the 'unspecified' impedance 'equivalent', which is the very reason it came into being. You don't need 'another one' for the same thing. dBu "came into being" because it is referenced to the voltage required to produce 1mW into 600ohms. If I know the 600, I can work out the 0.775 The voltage reference for dBu is specified as the same voltage 0 dBm produces into 600 Ohms but dBu has no defined resistance. 0 dBu into 100k Ohms is the same as 0 dBu into 1k ohms, is the same for 10 ohm, is the same for 1 ohm despite it being blindingly obvious those are not the same powers. And the reason is that 0 dBu is .775 V regardless of the unspecified R. Professional Line Level isn't operating at 600 Ohms so what would +4dBu mean with your presumption of 'power'? Its the voltage that would result in +4dB relative to the power produced by 1mV into 600ohms. Except there is no 600 Ohms and that power is never produced. My bad for a poor example. I should have used -10dBV so you couldn't play games with the reference point being a conversion from a power domain to the voltage domain. So, repeat all that 'power produced by' explanation with -10dBV. Let's say we have a preamp putting out -10dBV (consumer line level) and we have both a tube amplifier with 100k inputs and a solid state amplifier with 10k inputs. Okay, which one is 'not seeing' -10dBV? Or is it both and what would I need for -10dBV? -10dBV is a voltage. And the only reason you know that is because you know the defined dBV reference is 1V. It is the voltage reduction that would result in a 10dB fall in power. What 'power' is -10 dBV or, since you like 'reduction from', what power is 0 dBV? Your question doesn't make sense. Of course it does. You keep claiming dB is 'all' power so tell me what the power is under those conditions. This is a common argument so I'm just running up the flag for the other side. You may say the Watts cancel out in the ratio, but I argue like a true dialectical materialist: their history remains. I'll stick with mathematics since there's a few thousand years of experience saying 'it works'. We can both do maths at this level, I trust. I wouldn't advise sticking to maths exclusively though...there's more to language, and the world, than logic. We've been though this before and if you want to spend your own time contemplating the galactic significance of a belly button then that's fine, for you. But I'm concerned with making circuits work and that doesn't contribute. When dealing with power the equation is 10Log(A1/A2) When dealing with voltage the equation is 20Log(A1/A2) The 2x, or .5x, depending on which side you prefer, captures the ^2 in the P=E^2/R relationship. 2x, please. .5x would be a silly contrivance. Maths alone won't tell you that. It simply depends on which side you like to view things. 2x, because log of a square is double. And .5 because the log of a square root is half. By convention, not by maths, dB is the log of a ratio of power. "By convention" there are two equations and you can find them in any textbook. If you know that, and 600ohms... oh and 75ohms for the dBmV and a few other odds and sods, I see, now I've looked it up, you can work the others out. Hehe. Yeah, and there are a lot more. And there is no way you can derive 'power' from dBV (and it never had a 'power' reference) nor dBfs, and a host of others. And, as you see from the plethora of definitions, 'dB', being a Log ratio, has no meaning without a reference. The fact of the matter is that in things like voltage amplifiers we are not concerned with signal 'power' but voltage levels. Now, given that alone we could use almost any convenient convention but we 'expect' that, sooner or later, there will be a conversion from the voltage domain to the power domain, such as the power output stage of an audio amplifier, so it is convenient to use a convention which maintains the same kind of relative relationship, hence the 20Log(A1/A2). It is this convenience you are confusing as a 'real power' when there is no load or current defined, nor is it constant, from which to derive such. Let's take the common example of a standalone preamp. There are A volts in and B volts out, for a gain of X dB (A being the reference) but we have no idea what 'power' any of that represents because, not only do we have no idea what the preamp load will be, we have no idea what the end 'power conversion' will be. Someone might plug that preamp into a 1 Watt SE with 100k inputs or a 400 Watt Phase Linear with 39k inputs, or Lord only knows what. dBV is not power. dBu is an example of the explanation just given because it is the result of conversion from the power domain into the voltage domain at the 'one point' of 0 dBm. I.E. Let us take the telephone system origins and observe we have 600 Ohm lines terminated into a voltage amplifier. There is dBm on the 600 Ohms, which creates a voltage. However, inside the amplifier there is no 600 Ohms nor do we care what the 'load' is from one amplifier stage to another. Here we use dBu, because all we have is voltage, and it only has '600 ohm' meaning if we do another conversion on the output side to a 600 Ohm line but, surprise!, we are actually building a speaker phone and it's going to output 150 mW into a 4 ohm load. Oops. dBu is not 'power'. Ian There is usually a 'reason' for the referenced picked (even if it's simply 'mathematically convenient'). In the digital audio world it's "full scale" because that's a brick wall. There are 'no more bits' and, so, that is a 'very important thing' to keep track of. All 'dB' will be 'minuses' below the brick wall. In the analog world, while there might be a nebulous point where distortion begins to set in, there is generally no 'brick wall' to pick. Instead, the 'reference' is that level which the ear perceives as 'average' program level, the point which comprises the bulk of what's 'heard'. There are then transient peaks above (plus dB) and 'quiet' passages below (minus dB) but '0 dB' is the 'normal level', a nebulous term to be sure but that is the 'art' of the audio engineer. I.E. picking levels that best accommodate transient peaks while keeping 'quiet' passages above the noise floor. All this means that 0 dBV is not 0 dBfs is not 0 VU (which, if I remember correctly, is, on tape machines, something like -8dB from the point where distortion hits 3%). Patrick Turner. Ian- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - |
|
#20
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 21, 11:27*pm, flipper wrote:
Do I care? Only in so far as I quite like thinking. Right thoughts are of no value, so I strive to propagate as many wrong thoughts as possible before breakfast, and spend the rest of the day sorting out the mess. Well, thank you for explaining your purpose is to come up with 'wrong thoughts' but, personally, I don't have the time to waste rehashing all the 'wrong thoughts' of history. Do wrong thoughts survive history? They are already taken and no longer available, surely? Spotting opportunities for genuine, virgin wrong thoughts is necessary for progress. To do that you need to position your thinking at the edge of the unknown, so you need a clear idea of where the edge of the known is. These days, there's not many wrong thoughts remaining, but that could change. We may have different conceptions of the universe, and our places in it. I hope to live forever, and there's plenty of time to be right in heaven. You appear to be missing your earthly vocation, which is to be wrong. Ian |
|
#21
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Mon, 21 Nov 2011 17:51:42 -0800 (PST), Ian Iveson
wrote: On Nov 21, 11:27*pm, flipper wrote: Do I care? Only in so far as I quite like thinking. Right thoughts are of no value, so I strive to propagate as many wrong thoughts as possible before breakfast, and spend the rest of the day sorting out the mess. Well, thank you for explaining your purpose is to come up with 'wrong thoughts' but, personally, I don't have the time to waste rehashing all the 'wrong thoughts' of history. Do wrong thoughts survive history? They are already taken and no longer available, surely? Spotting opportunities for genuine, virgin wrong thoughts is necessary for progress. To do that you need to position your thinking at the edge of the unknown, so you need a clear idea of where the edge of the known is. These days, there's not many wrong thoughts remaining, but that could change. We may have different conceptions of the universe, and our places in it. I hope to live forever, and there's plenty of time to be right in heaven. You appear to be missing your earthly vocation, which is to be wrong. Ian Enjoy your wrong thoughts. |
|
#22
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 22, 12:51*pm, Ian Iveson wrote:
On Nov 21, 11:27*pm, flipper wrote: Do I care? Only in so far as I quite like thinking. Right thoughts are of no value, so I strive to propagate as many wrong thoughts as possible before breakfast, and spend the rest of the day sorting out the mess. Well, thank you for explaining your purpose is to come up with 'wrong thoughts' but, personally, I don't have the time to waste rehashing all the 'wrong thoughts' of history. Do wrong thoughts survive history? They are already taken and no longer available, surely? Spotting opportunities for genuine, virgin wrong thoughts is necessary for progress. To do that you need to position your thinking at the edge of the unknown, so you need a clear idea of where the edge of the known is. These days, there's not many wrong thoughts remaining, but that could change. We may have different conceptions of the universe, and our places in it. I hope to live forever, and there's plenty of time to be right in heaven. You appear to be missing your earthly vocation, which is to be wrong. Ian Be careful spouting Gibberish like you do Ian, because you'll have Fipper telling you soon to stop posting gibberish, ie, anything which his poor little tiny brain doesn't agree with. Ah, there's nothing so silly, IMHO, as the optimism of God Botherers who like to suggest the next life in heaven is where they can finally get things right. Even Steve Jobs consulted gurus about alternative therapies for his cancer which killed him, rather than going to a doctor IMMEDIATELY, thus avoiding bull****. Patrick Turner. |
|
#23
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
I asked Ian......
?????? Speaking in Riddles Again Ian? Not intentionally. Congruent in this case means the same shape. Then you are definately Gibberizing Riddalatiously. If you derive a voltage from a current sensing resistor at the cathode of an output valve, then it looks roughly like the second diagram down on the illustrations in the Brook ad posted by flipper. Not so. Your'e wrong. Brook 10C ahs a common Rk. I have one Rk per tube, so there is a different wave in AB to that in any common Rk. Not only that, with the bjt working how it does, the wave at my Rk of 10r is a near aquare wave because as soon as Ia begins to exceed approximately 0.6V above 0V, the bjt begins to turn on, and just bypasses Ia instead of letting it charge Ck. This little square wave at each Rk on each side of the PP class AB circuit does not add any significant extra THD to the AB working pair, and in fact THD is virtually the same as a fixed bias amp. Like most dummy wannabes posing as jargo-experts, you fail to grasp the way things work before you've ever built a real working sample. The signal comprises the DC bias level with asymmetric AC imposed upon it. If the output valve is cutting off, then this AC component will be cut off at zero and will rise beyond twice the bias level. Now, if you use a grounded grid triode to amplify this signal, set up so that it clips when its input is twice bias level, then it will clip the peaks but not the troughs. If the triode's characteristics are the same shape as the output valves, the peaks and troughs will be the same shape. Then, if you integrate the signal with a cap, you get a steady representation of the bias level which then serves as feedback to the grid control circuit. I defy anyone to understand what you've just said, but hey, I know by DBS works OK, as I have built and tested it in several amplifier examples, so I don't have to waste my precious time reading your posts on this. I know its very rude of me to treat you and Fipper so badly, but I have a choice, spend a hundred hours a week arguing bull****, or spend that time in my shed constructively, and you know what choice I am likely to make.. You could use a transistor and a zener for the circuit I have described, so it cuts off at the right point. But it won't have the same distortion, so it won't perfectly cancel so it doesn't have the same attractive elegance. I first experimented with DBS using zeners and etc in cathode circuits in about 1998. The holy grail is bias control that keeps Ek constant at idle while also keeping Iadc in each 1/2 primary equal, and unaffected by Ia increase due to rectifier effects which cause gross over-biasing of the OP stage to class C operation if AB over drive is sustained. Standard fixed bias is good to stop rectifier effects and stop over biasing, but no good to hold idle Ek constant in cathode bias amps. My 1998 solution is far less than perfect, see http://www.turneraudio.com.au/dynacost70mods.htm Gain in the regulator circuit also allows for tighter control, resulting in fixed bias. It then makes more sense to apply the bias control voltage to the grid than to the low-impedance cathode. The posted circuit for the 10c doesn't show voltages, unfortunately, but it looks like an attempt at the perfect solution. If the triode in the current detector part of the circuit is set up right, then it should have equal distortion, and clip at the same point, but in the opposite direction, as the output valves. The output from the current detector then integrates to a constant DC value, which is used to determine the bias voltage. I wonder, as the control circuit valves age along with the output valves, whether they maintain the bias point in the same place relative to the characteristics of the output valves? That would solve a problem of fixed bias, which generally maintains a given current regardless of ageing, and so drifts in relation to valve characteristics. The Brook appears to me to have a dc amp and a FB loop, so tube ageing probably won't affect much until ageing severely affects the tubes, ie, tubes run out of emission oand thus gain. But to know just how the Brook 10c really works ya have to build and measure a sample. Flipper is desperately trying to avoid doing the work which would make the brook 10C so clear to him. Years ago, You tried to avoid buying a copy of the Radiotron Designer's Handbook. People love to run about talking to every issue, posing as a know all, jarging the jargon, but unless ppl, read the books, build the circuits, they remain in the dark. Morgan Jones in one of his books shows a comparatively crude SS version of the same circuit, using IIRC an opamp and a zener in place of the first triode in the Brook's control circuit, followed by the integrating LPF, and perhaps the other half of the opamp for the bias voltage output. Maybe discrete transistors instead of opamps...can't remember. There have been a pile of circuits for active bias control. Some have worked to just keep Ek and hence Ik of each tube balanced eith a diff pair amp to adjust Eg1 bias, but not to react to overall Eg1 rise in AB action. None have survived the test of time. You just make stuff up on the fly and don't read. The Brook that started all this fetched a fortune. That may have been easy in 1950, if you were an entrepreneur. Patents cost a lot, and sometimes ppl reap a benefit, but while Brook Brook 10C sales would have been +300dB more than my sales, there were umpteen other pll making amps which also sold well. I look at the vast array of old junk like the Brook and I never assess it like as if it was God's gift to audiophiles. American trickery fetching fortunes was mostly applied marketing. The Butcher's combination of loose regulation and tight fixed limiting, with incompletely-bypassed SS in the signal path, looks like a bodge. Can I assume you are referring to me as the Butcher? I guess so, typical, form a nincompoop like yourself, with such a tiny amount of experience building amps. I know nearly everything in the universe, but made only a small part of it. You know bugger all. So far you have failed the Turing test. Well, I don't have to worry that you say I failed the Turing test, because, as you have said, as only a really idiotic man can say, that "I know nearly everything in the universe." Considering his amps are well specified for purpose (ie big enough), however, there is possibly enough headroom so the circuit is largely redundant, because it's set to allow some drift before doing its thing. To paraphrase Jim, from time long gone, if it's big enough, nothing else matters. Sometimes its handy to make a cathode biased amp behave as a fixed bias amp where the power wanted is fairly high compared to clipping power. My Dynamic Bias Stabilizer circuit would of course, to you, look like a Dynamic Butcher's Stabilizer, and you like nothing more to pour a bucket of **** on it if possible, because you hate me for pulling you down with a tackle everytime you makea silly run with a ball. Well, I really don't care, I've demonstarted to myself that my BDS bias scheme vastly reduces the amount of THD that would other wise occur with sine wave operation taken up to clipping in a class AB amp. People see those bjts I have in there and the gasp in horror; what a rotten horrid nasty man I am to do such a beastly thing! But youse ain't built and tested my circuit now have youse? So what the **** would you know about it? On a related matter, while I'm passing, can anyone guide me to a clear definition of standard line level? I'm looking for an accepted standard for headroom. I have it in my head that a system should allow for 18dB above rms listening level. Tried looking but there's so much gobbledegook... To know how intrusive a limiter might be, either with the Butcher's bodge or my nascent headphone amp, it should strictly be necessary to know this. Also what kind of distribution, and what standard deviation, a piece of recorded music may have within that limit. Ian, you get First Prize for speaking in un-decypherable riddles. What the heck has line levels go to do with DBS. Relative amplitude, of course. Competent design of a device requires that its operating parameters are known and taken into account as far as possible. Your device intervenes at a "high" signal level, which happens "occasionally". Unless you know how high "high" is, how often high occurs, and whether highs come one at a time or in flurries, you don't know much about what your device is doing. You should do proper tests and publish them before you attempt to profit from your snake-oil. Ian I quite happily do not seek a profit, and merely wish for average weekly earnings. Nothing is done or said at Turner Audio for a profit motive, but is done because it is a good idea that works. One thing is for sure, I for one have never read anything you have ever said about amplifiers which I feel compelled to ever try. Once upon a time before I convinced you you really ought to buy a copy of the RDH4, I recall the rot started when you asked me about a circuit for an amp and I virtually had you aghast because basically I'd listed all manner of things leading to less THD which meant you'd have to abandon what ya had in mind, and start all over again, and ya didn't like that. So while ever we are in the same universe, you'll be dead set against me. I'd say you'll never ever believe that negative feedback exists in any triode. I was lucky that Dennis Assanayev put me right about triode FB, but you missed his message entirely. Have your usual horrible day Ian, after you'd made mistakes all morning, and then have to undo them from lunch to bed-time. And BTW, its a free world, and I don't have to wait for your approval before publishing amp ideas. Amazingly, not a living soul has disputed any part of my 22MB website. If I'd posted up an easy method for a fusion reactor that worked at room temp, I would have had few ppl try my idea, but of course I can't be as dumb as the last two guys who tried to tell a world a nice story about cheap energy. Patrick Turner. |
|
#24
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 22, 2:35*am, flipper wrote:
We may have different conceptions of the universe, and our places in it. I hope to live forever, and there's plenty of time to be right in heaven. You appear to be missing your earthly vocation, which is to be wrong. Ian Enjoy your wrong thoughts. I've lost hope of finding any here. For my own part there was a glimmer of hope until I checked the obvious sources. I feel you are reciting an opinion, regardless. Perhaps a dogma you picked up early and have never given thought to. Just in case your thought is genuine, you might try Wikipedia, which I trust has by this time distilled an acceptable consensus. Jackpot! Top enlightement! Don't miss this opportunity. I've lost the plot with this google view. Thanks for the info on standard levels. I'm more confident now that I've got the size of my headphone amp design right. My phones seem to be made for my CD player, and I just need a volume control and a buffer. Ian Ian |
|
#26
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
I look at the vast array of old junk like the Brook and I never assess
it like as if it was God's gift to audiophiles. American trickery fetching fortunes was mostly applied marketing. Patrick, if you don't believe there is a God, than why use the name in your posts?? Eddie "Patrick Turner" wrote in message ... I asked Ian...... ?????? Speaking in Riddles Again Ian? Not intentionally. Congruent in this case means the same shape. Then you are definately Gibberizing Riddalatiously. If you derive a voltage from a current sensing resistor at the cathode of an output valve, then it looks roughly like the second diagram down on the illustrations in the Brook ad posted by flipper. Not so. Your'e wrong. Brook 10C ahs a common Rk. I have one Rk per tube, so there is a different wave in AB to that in any common Rk. Not only that, with the bjt working how it does, the wave at my Rk of 10r is a near aquare wave because as soon as Ia begins to exceed approximately 0.6V above 0V, the bjt begins to turn on, and just bypasses Ia instead of letting it charge Ck. This little square wave at each Rk on each side of the PP class AB circuit does not add any significant extra THD to the AB working pair, and in fact THD is virtually the same as a fixed bias amp. Like most dummy wannabes posing as jargo-experts, you fail to grasp the way things work before you've ever built a real working sample. The signal comprises the DC bias level with asymmetric AC imposed upon it. If the output valve is cutting off, then this AC component will be cut off at zero and will rise beyond twice the bias level. Now, if you use a grounded grid triode to amplify this signal, set up so that it clips when its input is twice bias level, then it will clip the peaks but not the troughs. If the triode's characteristics are the same shape as the output valves, the peaks and troughs will be the same shape. Then, if you integrate the signal with a cap, you get a steady representation of the bias level which then serves as feedback to the grid control circuit. I defy anyone to understand what you've just said, but hey, I know by DBS works OK, as I have built and tested it in several amplifier examples, so I don't have to waste my precious time reading your posts on this. I know its very rude of me to treat you and Fipper so badly, but I have a choice, spend a hundred hours a week arguing bull****, or spend that time in my shed constructively, and you know what choice I am likely to make.. You could use a transistor and a zener for the circuit I have described, so it cuts off at the right point. But it won't have the same distortion, so it won't perfectly cancel so it doesn't have the same attractive elegance. I first experimented with DBS using zeners and etc in cathode circuits in about 1998. The holy grail is bias control that keeps Ek constant at idle while also keeping Iadc in each 1/2 primary equal, and unaffected by Ia increase due to rectifier effects which cause gross over-biasing of the OP stage to class C operation if AB over drive is sustained. Standard fixed bias is good to stop rectifier effects and stop over biasing, but no good to hold idle Ek constant in cathode bias amps. My 1998 solution is far less than perfect, see http://www.turneraudio.com.au/dynacost70mods.htm Gain in the regulator circuit also allows for tighter control, resulting in fixed bias. It then makes more sense to apply the bias control voltage to the grid than to the low-impedance cathode. The posted circuit for the 10c doesn't show voltages, unfortunately, but it looks like an attempt at the perfect solution. If the triode in the current detector part of the circuit is set up right, then it should have equal distortion, and clip at the same point, but in the opposite direction, as the output valves. The output from the current detector then integrates to a constant DC value, which is used to determine the bias voltage. I wonder, as the control circuit valves age along with the output valves, whether they maintain the bias point in the same place relative to the characteristics of the output valves? That would solve a problem of fixed bias, which generally maintains a given current regardless of ageing, and so drifts in relation to valve characteristics. The Brook appears to me to have a dc amp and a FB loop, so tube ageing probably won't affect much until ageing severely affects the tubes, ie, tubes run out of emission oand thus gain. But to know just how the Brook 10c really works ya have to build and measure a sample. Flipper is desperately trying to avoid doing the work which would make the brook 10C so clear to him. Years ago, You tried to avoid buying a copy of the Radiotron Designer's Handbook. People love to run about talking to every issue, posing as a know all, jarging the jargon, but unless ppl, read the books, build the circuits, they remain in the dark. Morgan Jones in one of his books shows a comparatively crude SS version of the same circuit, using IIRC an opamp and a zener in place of the first triode in the Brook's control circuit, followed by the integrating LPF, and perhaps the other half of the opamp for the bias voltage output. Maybe discrete transistors instead of opamps...can't remember. There have been a pile of circuits for active bias control. Some have worked to just keep Ek and hence Ik of each tube balanced eith a diff pair amp to adjust Eg1 bias, but not to react to overall Eg1 rise in AB action. None have survived the test of time. You just make stuff up on the fly and don't read. The Brook that started all this fetched a fortune. That may have been easy in 1950, if you were an entrepreneur. Patents cost a lot, and sometimes ppl reap a benefit, but while Brook Brook 10C sales would have been +300dB more than my sales, there were umpteen other pll making amps which also sold well. I look at the vast array of old junk like the Brook and I never assess it like as if it was God's gift to audiophiles. American trickery fetching fortunes was mostly applied marketing. The Butcher's combination of loose regulation and tight fixed limiting, with incompletely-bypassed SS in the signal path, looks like a bodge. Can I assume you are referring to me as the Butcher? I guess so, typical, form a nincompoop like yourself, with such a tiny amount of experience building amps. I know nearly everything in the universe, but made only a small part of it. You know bugger all. So far you have failed the Turing test. Well, I don't have to worry that you say I failed the Turing test, because, as you have said, as only a really idiotic man can say, that "I know nearly everything in the universe." Considering his amps are well specified for purpose (ie big enough), however, there is possibly enough headroom so the circuit is largely redundant, because it's set to allow some drift before doing its thing. To paraphrase Jim, from time long gone, if it's big enough, nothing else matters. Sometimes its handy to make a cathode biased amp behave as a fixed bias amp where the power wanted is fairly high compared to clipping power. My Dynamic Bias Stabilizer circuit would of course, to you, look like a Dynamic Butcher's Stabilizer, and you like nothing more to pour a bucket of **** on it if possible, because you hate me for pulling you down with a tackle everytime you makea silly run with a ball. Well, I really don't care, I've demonstarted to myself that my BDS bias scheme vastly reduces the amount of THD that would other wise occur with sine wave operation taken up to clipping in a class AB amp. People see those bjts I have in there and the gasp in horror; what a rotten horrid nasty man I am to do such a beastly thing! But youse ain't built and tested my circuit now have youse? So what the **** would you know about it? On a related matter, while I'm passing, can anyone guide me to a clear definition of standard line level? I'm looking for an accepted standard for headroom. I have it in my head that a system should allow for 18dB above rms listening level. Tried looking but there's so much gobbledegook... To know how intrusive a limiter might be, either with the Butcher's bodge or my nascent headphone amp, it should strictly be necessary to know this. Also what kind of distribution, and what standard deviation, a piece of recorded music may have within that limit. Ian, you get First Prize for speaking in un-decypherable riddles. What the heck has line levels go to do with DBS. Relative amplitude, of course. Competent design of a device requires that its operating parameters are known and taken into account as far as possible. Your device intervenes at a "high" signal level, which happens "occasionally". Unless you know how high "high" is, how often high occurs, and whether highs come one at a time or in flurries, you don't know much about what your device is doing. You should do proper tests and publish them before you attempt to profit from your snake-oil. Ian I quite happily do not seek a profit, and merely wish for average weekly earnings. Nothing is done or said at Turner Audio for a profit motive, but is done because it is a good idea that works. One thing is for sure, I for one have never read anything you have ever said about amplifiers which I feel compelled to ever try. Once upon a time before I convinced you you really ought to buy a copy of the RDH4, I recall the rot started when you asked me about a circuit for an amp and I virtually had you aghast because basically I'd listed all manner of things leading to less THD which meant you'd have to abandon what ya had in mind, and start all over again, and ya didn't like that. So while ever we are in the same universe, you'll be dead set against me. I'd say you'll never ever believe that negative feedback exists in any triode. I was lucky that Dennis Assanayev put me right about triode FB, but you missed his message entirely. Have your usual horrible day Ian, after you'd made mistakes all morning, and then have to undo them from lunch to bed-time. And BTW, its a free world, and I don't have to wait for your approval before publishing amp ideas. Amazingly, not a living soul has disputed any part of my 22MB website. If I'd posted up an easy method for a fusion reactor that worked at room temp, I would have had few ppl try my idea, but of course I can't be as dumb as the last two guys who tried to tell a world a nice story about cheap energy. Patrick Turner. |
|
#27
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Tue, 22 Nov 2011 04:12:53 -0800 (PST), Patrick Turner
wrote: snip I quite happily do not seek a profit, Then why do it? and merely wish for average weekly earnings. *That* is *profit*. Nothing is done or said at Turner Audio for a profit motive, but is done because it is a good idea that works. *Everything* is done in anticipation of "profit," right down to the lowliest micro-organism wriggling for a morsel of energy since, if it expends more in the effort than gained, it dies without the profit. Mankind is, of course, more complex than a micro-organism and, so, has more goals than simply survival and procreation, but the same equation applies to any and all because it is axiomatic to achieving anything. You do not 'get there' unless your efforts move you closer to the goal, which is *profit*, and if you don't expect the effort will further some desired goal, I.E. you *profit*, then you don't do it. snip Patrick Turner. |
|
#28
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
I spoke the truth when I typed this :-
I quite happily do not seek a profit, Flipper can't believe the truth when he's told the truth, and asks the stupid question.... Then why do it? and merely wish for average weekly earnings. *That* is *profit*. Profit is considerd here by most ordinary punters as something ABOVE earnings and can be divided amoung shareholders, invested in shares, or spent on luxuries.. That is how its considered here. Profit is the freebie after you've been paid a wage. But the Tax Office sees it your way, if income exceeds costs by $1, then you've made a profit, and tax is liable and costs of production are deductable from gross income. But a loss of $1 may make one's activities into what is called a hobby, and costs are not deductable from gross income. Its all a bit queer, because then the loss is much greater, on paper, but there's still no higher liability for tax. But the tax act has 1,600 pages, and just like you, I ain't no expert. If you wanna discuss profits, and the profit motive, then you must be prepared to discuss losses, and the motive to create losses, or to avoid them. Carefully considering profits and losses by companies with enough dough to be creative about such things over short or long term is all a very murky human endeavour. Nothing is done or said at Turner Audio for a profit motive, but is done because it is a good idea that works. *Everything* is done in anticipation of "profit," right down to the lowliest micro-organism wriggling for a morsel of energy since, if it expends more in the effort than gained, it dies without the profit. There are, in many companies making audio gear, a team of accountants called bean counters who make sure a whole lot of things are NOT DONE to ensure high profits after they have all been paid their wages. I don't need a high wage, or any profit to exist as a self employed "sole trader" who sees that employing a ****ing accountant parasite would be completely destructive to my serene existance. Mass production and exploitation of Chinese labour on slave labour rates could be used to make my productions far more "profitable" than they are, ie, If I went to China to supervise production with a suitcase of venture capital. I'd end up with a good wage plus plenty left over, but I'd have to work 80 hours a week to ensure **** didn't happen and that the dream came true due to a concert of team work. To do well, I'd need to learn to speak Chinese. I'm not motivated by the profit motive at all, because that's energetic young dudes. So instead, I make one amp masterpiece at a time, in a year, and then the world is free to argue and throw buckets of **** and I can sit back and laugh, while telling them what they can't do. Maybe I am sadistic. I'd call it idealistic, because music ppl hear benefits. Now Flipper, just what to you create that anyone would ever wanna buy? The world is fulla goods that have been dumbed down to the lowest common denominator. For example, there's a bloke here who wants to make a tube amp during conversations with me he says he was installing air con units, and although there are many brands available, most come come 2 factories in China, and are copies of what was made in the West. These look so close to western originals, noboby can tell any difference, down to the labels and warranty paper work. Hidden internal contruction integrity is poor Chinese quality. Globalisation. One company finds a way out of providing quality by exploiting Chinese labour and crummy practices, then like lemmings they all go that way, and all is ticky-tacky crap. This is a result of companies fighting each other for market share, trying desperately to make profits. You said """ *Everything* is done in anticipation of "profit," right down to the lowliest micro-organism wriggling for a morsel of energy since, if it expends more in the effort than gained, it dies without the profit. """ This means a whole lotta things just ain't done when clearly there is a better way, but companies would be rooned if they do these things. Companies deserve to die if they put profit above quality. The banks with their wacky "investment products" which put the US economy into such a mess are an example. Everyone wants this and that and it all becomes a mirage with too much capitalism and profit seeking. I've often anticipated making a profit, but always known it probably will never happen. That's because where profits are made, serious compromises to quality and human rights have been made. The Chinese supply the West with gear priced at 1/2 the western cost of production. So here, manufacturing is in decline. The Chinese is a Communist controlled nation without what we know as democracy, and the powerful few keep the workers on 70c an hour, and so they get huge "profits" from producing goods sold to the west at marginally lower prices while trampling on their own ppl. The profits are invested wherever possible into the US economy, and now just how much does China own the US? 3 trillion maybe? who knows. So when the western nations cave in to old age laziness and profits look threatened by western nation dysfunction, China can even afford to prop up the west to keep the wheel turning. People are like rats, and skurry after the best deal, and to escape the work and stuggle, and convince themselves they are happy by conspicuus consumption and expense on putting on the agony, putting on the style. I doubt Flipper understands this. But look at the economic mess the world is in because of your preferred horrible ideas. A lot of ppl must hate me because I refuse to catow to mainstream practices. I don't care about their idiotic attempts to whittle down the quality to make the price "competitive." Mankind is, of course, more complex than a micro-organism and, so, has more goals than simply survival and procreation, but the same equation applies to any and all because it is axiomatic to achieving anything. You do not 'get there' unless your efforts move you closer to the goal, which is *profit*, and if you don't expect the effort will further some desired goal, I.E. you *profit*, then you don't do it. That's all Capitalist Propaganda. Its led to things like the Depression, and the recent GFC. Everyone wants profits on top of wages, and plays all these power games to get there, so you end up with many pigs at the trough suffing themselves fatly with profits, while reducing quality to zero, and keeping prices high, supported by paid liars called marketting executives. But saying that don't make me a socialist, because complete socialism works even worse than capitalism, because you can't own your own production, or own your factory, your shop, or even your land, or home, and everyone is supposed to be equal, whether they work or not. Mankind is fairly simple really, a mass of dumb brutes with a varying record of being decent human beings. We have seven virtues and seven vices, and production is affected badly by all sorts of vice. When we grow grain, we like to grow enough for hard times, that's wise, but some cannot resist wanting harvest many times what they would keep for hard times, they buy out their neighbours, lower all the wages of ppl employed, outsource all they can, and take the subsidies from Govt and have powerful lobby groups to control politics, and then they want access to international markets to undercut local productions to make everyone else catow to their product. They even push their Govt to make wars against other nations, foster coups against regimes they don't like. I hate Mc Donalds. I WILL NOT EAT AT McDONALDS. Last time I did, in 1993, I felt sick, and paid too much. I will not drink Coca Cola. Ppl have told me they have visited the US and found that their bread in shops is about the worst in the world. But look at all the other supermarket products, all based on the profit motive. Look at US obesity and US waistlines and US rates of diabeties. Crappity crap all over. When one leaves out the profit motive from the Police Force, and Medical Treatments, everyone gets better policing, and things like Medicare in Oz where what would cost $100,000 from a private US medical company cost NOTHING at the local hospital. Profits cause corruption The police and the hospital doctors get paid a good wage, but there are no profits to allow police and hospital doctors to get 10 times the wage rates they get now. Profit is forgone to allow all society to live well with affordable law, order, and medical care. The public school school systen is also run this way, so it doesn't cost an arm and a leg for education. Of course we do have private medical companies who offer services for a whopping obscene fee. Some docs do the ****ing american dance, and want $50,000 for a morning's cut&sew in a op theatre. Rich people will pay huge prices to stay alive. They got their money from everyone else. I quite admire the way the Amish run their style of living, no frills. Of course they don't have electricity so it'd be useless me building tube amps in Amish country. I wouldn't even be allowed to. But I could ride a bike, or make wagon wheels, and have a whole lot of other things, many of which money can't buy. I'm quite happy without ever wanting 90% of what is made by mainstream profit driven production methods. Patrick Turner. |
|
#29
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Nov 25, 10:45*pm, mistikuss
wrote: [image:http://allall.us/smail1.gif] -- mistikuss The condition of mankind is perpetual mystification; we cannot fully understand anything, and cannot really want what we don't understand, but we just shrug, say "whatever" and pay for yet more stuff that the advertising industry has told us to buy, so somebody@somedamnwhere makes a profit, or gets exploited, ripped off, or as they say "whatever". Nobody cares for the ultimate results of their transactions. Along with my refusal to happily pay for McDonalds burgers or Coca Cola, it is unavoidable that I pay for massed produced stuff to have a life with enough spare time to be able to type to the world that my existance has little meaning. But while the certainty remains that there is uncertainty, it remains a mystery why Flipper defends the Brook 10C biasing described confusingly by the lawyers who wrote a patent. If Flipper wants to lessen certainty, he must prove he understands the Brook, or at least admit he could be wrong, something he is stubbornly refusing to do, lest he loose face, and suffer being judged a dummy. I already know I could be wrong about anything. Don't ever take my word as gospel, but hey, feel welcome to try any of my circuits published at my website. This is my simple stance. Patrick Turner. |
|
#30
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
Delete much **** typed at me.
Fipper lies with :- I haven't thrown '****' at anyone, that's your specialty. Although, it's hardly unique or an honor as you hurl it at just about every one and every thing. Flipper takes time out to thow **** instead of just building Brook 10C to show us all he knows what he's talking about. Patrick Turner. |
|
#31
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Sun, 4 Dec 2011 00:13:01 -0800 (PST), Patrick Turner
wrote: Delete much **** typed at me. Fipper lies with :- I haven't thrown '****' at anyone, that's your specialty. Although, it's hardly unique or an honor as you hurl it at just about every one and every thing. Flipper takes time out to thow **** instead of just building Brook 10C to show us all he knows what he's talking about. Patrick Turner. You're the only one confused so you go build one. |
|
#32
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Dec 2, 2:11*am, flipper wrote:
The Chinese is a Communist controlled nation No sheet, Sherlock. Which makes all that babble because they are *not* a democracy nor operating a free market. Oi! That would depend on how you define democracy. Your liberal idea that it allows everybody to do what they want is clearly naive. Consider the huge proportion of US citizens in prison. The central problem of the liberal European conception of democracy inherited by the US and Australia is that one man's liberty is another man's restraint. Individual libery is its own undoing. As millions of people in states previously part of the Soviet Union have rediscovered, the liberal conception of freedom is meaningless for those without resources, who have no choice but to sell their freedom every hour of every day for food and warmth. Liberalist propaganda is so thoroughly duplicitous that I despair for anyone witless enough to swallow it. On the one hand the Chinese people are downtrodden and have no say in the running of the state, and on the other the Communist Party is so fearful of civil revolt arising from the many issue-based protests taking place every day that it's policies are driven by paranoia. Is it really hard to see that these two propositions are diametrically opposed? In China, everyone can thoroughly consider and vote on every issue and, once decisions are made, everyone must stick to them. It's a long way from perfect, of course, as the Party itself frequently points out...socialism is struggling and Communism is a long way off. The whole business of creating socialism without preceeding capitalism, considered impossible by many Communists including Marx and Engels, is touch and go to say the least. Hence the uncomfortably risky creation of a quasi-capitalist driver for industrial progress. In case it has escaped your notice (it must certainly escape the Butcher's), many of the enjoyable aspects of the liberal democracies we love are disappearing fast. Our states just don't work without growth. As every good Communist knows, if we're not moving forwards, we're slipping backwards. No more the freedom of travel for the majority. No more the freedom of owning a house, borrowing money to start a business, buying a new car. We were free to stop making things. Our financial institutions were free to invest our dwindling surplus product in...China. Ha ha, we thought...and still think in so many cases...let's take advantage of those poor downtrodden cheap labourers. Chinese labour has not been cheap when you take into account the social costs of providing for the startling progress of its productivity. A significant proportion of the investment in that progress was from our liberal democracies. Consequently, by sleight of the invisible hand of capital, we owe China ****loads of stuff. Then we gobbled up everything we could get our hands on from China because we loved exploiting that cheap labour. Consequently we owe China ****loads more stuff. Unfortunately, and especially in the case of Britain, we've stopped making stuff. We've even largely stopped digging stuff up, and have lost or abandoned many of the places we dug in anyway. The defining feature of the success of Chinese labour is not its cheapness, but the epic scale and effectiveness of its organisation. I remember enthusing here about the Beijing Olympic ceremony...about the stunning co-ordination of so many performers, and about the speech from the General Secretary of the Communist Party, in which he announced the Green China initiative. Just a couple of years after the US said it couldn't afford to let China take the lead in the alternative energy market, China is building wind farms in the US. Take any industrial sector you like and the story is much the same. Wake up. Blink. Consider the true value of labour rather than its cheapness. The value of Chinese labour is supported by the raw materials that our capital abandoned, it is multplied by a level of organisation that we never achieved even when we tried hard, and it is further multiplied by its tooling and its adaptable infrastucture. Our tooling is on rusty scrapheaps, and we don't have enough resources to invest in infrastructure. Germany excepted, for the moment. So who will be tomorrow's cheap labour? Who risks being tomorrow's cannon-fodder? Who's most likely to find themselves in a brutal dictatorship? When it's up against the wall, capital doesn't do totalitarianism by halves. Stop carping. Help China show the way forward. Better red than dead. Ian |
|
#33
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Sun, 4 Dec 2011 10:20:16 -0800 (PST), Ian Iveson
wrote: On Dec 2, 2:11*am, flipper wrote: The Chinese is a Communist controlled nation No sheet, Sherlock. Which makes all that babble because they are *not* a democracy nor operating a free market. Oi! Oi is right. Oi, how you can jump into a political rant from a simple statement that you can't use two different things as a critique of each other. It's like critiquing an F-22 Raptor by pointing at perceived flaws in a Ford Taurus. It's nonsensical because they don't operate from the same principles. That would depend on how you define democracy. How about using the one found in dictionaries and PoliSci textbooks? Your liberal idea that it allows everybody to do what they want is clearly naive. I don't know who told you democracy "allows everybody to do what they want" but it sure as hell wasn't me. The later is called "freedom" and democracy is a form of government, all of which necessarily limit freedom. As Ben Franklin so wittily put it, democracy is two wolves and a sheep 'voting' on what to have for dinner. Freedom is a well armed sheep contesting the vote. Consider the huge proportion of US citizens in prison. Security is the first and primary reason why governments are formed. The central problem of the liberal European conception of democracy inherited by the US and Australia Back your horses up there. American philosophy draws upon Locke, et al, but Europe never embraced it like Jefferson, Madison, el al, did. Claiming they're 'the same' is akin to claiming humans and monkeys are identical because somewhere in the past there was a 'common ancestor'. is that one man's liberty is another man's restraint. I don't know what 'Europe' thinks on that score but the proper expression is "one man's liberty ends where the other's begins" or, to put more colloquially, your freedom to swing a fist ends at the tip of my nose. It is not "one man's liberty is another man's restraint" because the same admonition 'swings' (pun) both ways. It is a *common*, to all, liberty and a *common*, to all, restraint. That's where the "equal" in Jefferson's "all men are created equal" part comes in. All have the same inherent rights and the same obligation to not infringe on his fellow man, because the rights are equal. Neither you nor he have 'extra' rights. Different weight, height, skin color, eyes, hair, strengths and skills, yes, but not different rights. Individual libery is its own undoing. Based on what? How is your and my freedom to do as we please, as long as we harm no one in the process, an 'undoing'? As millions of people in states previously part of the Soviet Union have rediscovered, the liberal conception of freedom is meaningless for those without resources, who have no choice but to sell their freedom every hour of every day for food and warmth. Hogwash. Freedom is the ability to do what one wants. It is not a guarantee of 'subsidy' or any other giving/taking from others. Food, to take one of your examples, does not spontaneously leap forth into your belly. You have to work for it, whether that be by foraging the jungle, planting crops, bartering with goods you've made, or 'selling' the same labor for funds to purchase it. If you want to talk about freedom just imagine yourself on an African savanna circa 200,000 BC all by yourself, absolutely free to do as you please, and then tell me you wouldn't have sold your soul for a nice 8-5 and a grocery store. Liberalist propaganda is so thoroughly duplicitous that I despair for anyone witless enough to swallow it. On the one hand the Chinese people are downtrodden and have no say in the running of the state, and on the other the Communist Party is so fearful of civil revolt arising from the many issue-based protests taking place every day that it's policies are driven by paranoia. Is it really hard to see that these two propositions are diametrically opposed? Why the hell are you talking to me? Go argue with someone who said those things if you want an explanation of it. In China, everyone can thoroughly consider and vote on every issue and, once decisions are made, everyone must stick to them. That's a joke, right? It's a long way from perfect, of course, as the Party itself frequently points out... Isn't that sweet. socialism is struggling and Communism is a long way off. Well, no sheet, Sherlock. The perennial communist lament; that some day, some one, will figure out how to make it happen. The whole business of creating socialism without preceeding capitalism, considered impossible by many Communists including Marx and Engels, is touch and go to say the least. You leave out 'why'. It's considered 'necessary' to so completely screw things up the people will then 'revolt' for the 'right way'. The Chinese government isn't looking for a revolt, they already won that one. Hence the uncomfortably risky creation of a quasi-capitalist driver for industrial progress. Piffle. They discovered profit works. They're banking on 'controlling' it. The West is betting on a 'reverse Marx' effect. In case it has escaped your notice (it must certainly escape the Butcher's), many of the enjoyable aspects of the liberal democracies we love are disappearing fast. And which ones are those? 'Freebies'? Our states just don't work without growth. States work just fine without growth. It's people that want it. 'Growth' is what makes it possible to 'grow' from living in a one horse one room log cabin to a 2 car 3 bedroom house/apartment with sewer, running water, central heat, and a wide screen TV. As every good Communist knows, if we're not moving forwards, we're slipping backwards. A 'good communist' wants not these things (Yoda). No more the freedom of travel for the majority. No more the freedom of owning a house, borrowing money to start a business, buying a new car. We were free to stop making things. The U.S. is neither China nor Europe... yet. Our financial institutions were free to invest our dwindling surplus product in...China. Ha ha, we thought...and still think in so many cases...let's take advantage of those poor downtrodden cheap labourers. Speak for yourself. Chinese labour has not been cheap when you take into account the social costs of providing for the startling progress of its productivity. A significant proportion of the investment in that progress was from our liberal democracies. Consequently, by sleight of the invisible hand of capital, we owe China ****loads of stuff. It isn't because of 'capital'. They're getting a return on the investment. Then we gobbled up everything we could get our hands on from China because we loved exploiting that cheap labour. Speak for yourself. Consequently we owe China ****loads more stuff. Unfortunately, and especially in the case of Britain, we've stopped making stuff. We've even largely stopped digging stuff up, and have lost or abandoned many of the places we dug in anyway. As Margaret Thatcher warned, sooner or later you run out of someone else's money. The defining feature of the success of Chinese labour is not its cheapness, but the epic scale and effectiveness of its organisation. I remember enthusing here about the Beijing Olympic ceremony...about the stunning co-ordination of so many performers, and about the speech from the General Secretary of the Communist Party, in which he announced the Green China initiative. Was that before or after they said you can shove Kyoto up your EU? Just a couple of years after the US said it couldn't afford to let China take the lead in the alternative energy market, You might as well quote Bugs Bunny as Obama, for all it's worth. China is building wind farms in the US. Take any industrial sector you like and the story is much the same. No, but it's too complex to go into here. Wake up. Blink. Consider the true value of labour rather than its cheapness. The value of labor is what someone is willing to pay, just as that's the value of anything else. The value of Chinese labour is supported by the raw materials that our capital abandoned, it is multplied by a level of organisation that we never achieved even when we tried hard, and it is further multiplied by its tooling and its adaptable infrastucture. The Egyptians were good at building things too. Totalitarianism and slave labor can be efficient, if you're ruthless enough. Or at least so it seems because everyone but you is 'paying' for it. We go through this nonsense every time some totalitarian regime appears to 'do well'. Everyone was fawning over the NAZI 'economic miracle' and then hand wringing over the Soviet Union "winning the space race," at the same time they were building a barbed wire machine gun armed wall around the whole thing to keep their people from escaping. No, thank you. I have no desire to push stones for the Pharaoh, *or* the State. Our tooling is on rusty scrapheaps, and we don't have enough resources to invest in infrastructure. That's because the money was extracted from the private sector and spent on other things. Germany excepted, for the moment. So who will be tomorrow's cheap labour? Who risks being tomorrow's cannon-fodder? Who's most likely to find themselves in a brutal dictatorship? When it's up against the wall, capital doesn't do totalitarianism by halves. Stop carping. Help China show the way forward. Better red than dead. Europe, with the U.S. lagging behind, has been trying to 'out socialist' the communists for over half a century but they're burdened by not having the totalitarian guts to roll tanks over their own citizens in the town square. Ian |
|
#34
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Dec 5, 1:48*am, flipper wrote:
On Sun, 4 Dec 2011 10:20:16 -0800 (PST), Ian Iveson wrote: On Dec 2, 2:11*am, flipper wrote: The Chinese is a Communist controlled nation No sheet, Sherlock. Which makes all that babble because they are *not* a democracy nor operating a free market. Oi! Oi is right. Oi, how you can jump into a political rant from a simple statement that you can't use two different things as a critique of each other. It's like critiquing an F-22 Raptor by pointing at perceived flaws in a Ford Taurus. It's nonsensical because they don't operate from the same principles. Er, no it isn't. I don't even know what a Raptor or a Taurus is. I'm objecting to your contention that China is not a democracy. That would depend on how you define democracy. See? How about using the one found in dictionaries and PoliSci textbooks? I don't want to get you into trouble with the law but, assuming you are in America, are your dictionaries and textbooks censored? Can you get Wikipedia? http://en.wikipedia.org/wiki/Democracy In Britain, our textbooks have pretty much the same stuff in them, including "parcipitatory democracy", "direct democracy", "soviet" or "council democracy", all of which apply to some degree in China. Also, one would expect to find some reference to "Marxist democracy". The term I favour is "democratic centralism", because it makes the dialectic explicit. Your liberal idea that it allows everybody to do what they want is clearly naive. I don't know who told you democracy "allows everybody to do what they want" but it sure as hell wasn't me. The later is called "freedom" and democracy is a form of government, all of which necessarily limit freedom. That wiki page will shed some light I hope. The concepts of freedom and equality are at the core of all notions of democracy. Your government is supposed to be safeguarding and supporting freedom, not constraining it. The fact that constraining freedom is necessary for supporting it is an unfortunate twist of the dialectic. As Ben Franklin so wittily put it, democracy is two wolves and a sheep 'voting' on what to have for dinner. Freedom is a well armed sheep contesting the vote. Ah, the sweet innocence of Looney Tunes. Whatever happened to American wit? I watched "Friends" once. Clearly the outcome is one fat wolf, or one lucky sheep. Alternatively, after an arms race, there could be just a crater. Consider the huge proportion of US citizens in prison. Security is the first and primary reason why governments are formed. Sad reductionism. The primary role of government has been to manage the surplus product necessary for surviving crop failure. Security is just one part of that responsibility. The central problem of the liberal European conception of democracy inherited by the US and Australia Back your horses up there. American philosophy draws upon Locke, et al, but Europe never embraced it like Jefferson, Madison, el al, did. Of course not. Liberal democracy develops, and America is a more recent formulation. Claiming they're 'the same' is akin to claiming humans and monkeys are identical because somewhere in the past there was a 'common ancestor'. I didn't say the same. The conception of liberal democracy was inherited from Europe, rather from American natives or Africans. It's form is American now, but the squabbling factions who led to its constitution were Europeans. is that one man's liberty is another man's restraint. I don't know what 'Europe' thinks on that score but the proper expression is "one man's liberty ends where the other's begins" or, to put more colloquially, your freedom to swing a fist ends at the tip of my nose. Whatever. Same point. It is not "one man's liberty is another man's restraint" because the same admonition 'swings' (pun) both ways. It is a *common*, to all, liberty and a *common*, to all, restraint. Yes, what a perfect expression of the dialectic. The force arising from that interdependence of opposites drives political science. Freedom, via restraint, is forced to act against its own self. Restraint, via freedom, is likewise afflicted. This is how the dialectic works to resolve the paradox. A small group of struggling hunter-gatherers has few restraints, but on the other hand has few options in life, and hence scant freedom. Larger, more highly organised groups restrain personal freedom more, but the group as a whole has more options when it comes to exploiting its environment, and these options are shared to the extent that the group is democratic. Consequently restraint generates freedom, and vice versa. The form of democracy most appropriate is the one most able to mediate this dynamic in a progressive and safe manner. That's where the "equal" in Jefferson's "all men are created equal" part comes in. All have the same inherent rights and the same obligation to not infringe on his fellow man, because the rights are equal. Neither you nor he have 'extra' rights. Different weight, height, skin color, eyes, hair, strengths and skills, yes, but not different rights. Individual libery is its own undoing. Based on what? Actually that's just one half of the equation. Based on the dialectic above. Free people organise to increase their options and so become more free. Individual freedom by this process is subsumed by social freedom. The other half of the equation is that social freedom is shared by participating individuals, and an organised society may make specific provision for individual liberty. There was a time, for example, when "an Englishman's home is his castle" had some legal currency. How is your and my freedom to do as we please, as long as we harm no one in the process, an 'undoing'? Where there is competition for resources, doing as you please will inevitably restrict the freedom of others. I am not free to eat the food you have eaten, or stand in the space you are in. As millions of people in states previously part of the Soviet Union have rediscovered, the liberal conception of freedom is meaningless for those without resources, who have no choice but to sell their freedom every hour of every day for food and warmth. Hogwash. Freedom is the ability to do what one wants. It is not a guarantee of 'subsidy' or any other giving/taking from others. Freedom is about having options. If you have no land and no money in much of the former Soviet Union, you have no option other than to do what someone else tells you pretty much all of your waking hours. The basic processes of sharing social freedom have largely disappeared. They are back to the final phase of feudalism, when people lost their land to the lords, and flocked starving to the growing cities to find whatever work they could get. No resources, no options at all. Food, to take one of your examples, does not spontaneously leap forth into your belly. Oh. No wonder I'm so thin. You have to work for it, whether that be by foraging the jungle, planting crops, bartering with goods you've made, or 'selling' the same labor for funds to purchase it. In Britain, if I went foraging or planting crops I'd find an angry landowner on my tail with a hotline to the police. No point in trying to compete with organised social labour when it comes to the making of most saleable goods. I'd have to be a proper artisan like the Butcher, and sell to rich people, like a Saville Row tailor. Grovelling, which doesn't appeal to my sense of freedom, is the key to that relationship. As for selling labour, in the sense of working for a wage, that *is* selling freedom, in so far as the workplace is not democratic. Only a part of that freedom is returned to me, and less to the state, so for the low-waged, there is likely to be a net loss. If you want to talk about freedom just imagine yourself on an African savanna circa 200,000 BC all by yourself, absolutely free to do as you please, and then tell me you wouldn't have sold your soul for a nice 8-5 and a grocery store. I don't need to. I value my personal freedom for exactly the same reasons you do. I would certainly make a fuss about dictionary censorship. I am also aware that my freedom rides on the back of millions of people, throughout history and now and apparently in the future, who suffer for my affluence, and who's freedom I have stolen. Liberalist propaganda is so thoroughly duplicitous that I despair for anyone witless enough to swallow it. On the one hand the Chinese people are downtrodden and have no say in the running of the state, and on the other the Communist Party is so fearful of civil revolt arising from the many issue-based protests taking place every day that it's policies are driven by paranoia. Is it really hard to see that these two propositions are diametrically opposed? Why the hell are you talking to me? Go argue with someone who said those things if you want an explanation of it. This is the internet. I'm talking to the world. I'm asking if that is hard to see, not for an explanation of why. InChina, everyone can thoroughly consider and vote on every issue and, once decisions are made, everyone must stick to them. That's a joke, right? No, it's true. There are serious penalties for not sticking to decisions. It's no joke. Corruption is of particular concern, particularly because capital will now constantly seek ways to exercise power. This is the biggest problem of political science they face in my view. Keep in mind that the only way forward is to struggle towards communism, and so any social revolution could only be a backslide into capitalism. If it's the voting part that you doubt, then yes, Chinese people argue and vote interminably at every level. Over ten percent of them are Communist Party members, and the party votes on every issue. Party members have a duty to include everyone in local decision-making so the Party as a whole is socially aware. I know from my own experience that such a form of democracy offers a different feeling of freedom. It depends in part, for example, on unanimous votes, because voting in spite of dissent is an attack on freedom. Hence debate continues until everyone agrees, or is at least happy they got the best deal possible. It's that debate that returns the freedom. Nobody denies that this can all go horribly wrong. What can't? http://www.chinatoday.com/org/cpc/ It's a long way from perfect, of course, as the Party itself frequently points out... Isn't that sweet. Cheap jibe. Socialism is a rocky path for freedom. So it was, and most certainly will be, for Capitalism, for most people. socialism is struggling and Communism is a long way off. Well, no sheet, Sherlock. Back off, poodle. It's a serious problem for human survival. The perennial communist lament; that some day, some one, will figure out how to make it happen. It's the appliance of science. We *know* it must happen or die trying. The problem of socialism is how to manage the inevitable transition so the baby doesn't get thrown out with the bathwater. The whole business of creating socialism without preceeding capitalism, considered impossible by many Communists including Marx and Engels, is touch and go to say the least. You leave out 'why'. It's considered 'necessary' to so completely screw things up the people will then 'revolt' for the 'right way'. If there are Americans who think this is the way to socialism, you can be sure they are not Communists. They may be Trotskyists, or Anarchists, or inhabit other refuges for disgruntled middle-class brats who won't suffer the consequences of foolish adventure. The role of Communists in a Capitalist state is to support workers in their struggle to regain the freedom lost to wage labour, not to impoverish them. This includes, in times of crises of capital like now, defending the state against Fascism. Unfortunately I appear to be the only remaining British communist. Occasionally, like the lone wren in my honeysuckle, I sing in hope. Luckily Fascists in Bradford are too scared to declare themselves, and elsewhere the Trots and Anachists beat them up. Following so soon after the collapse of the fatally corrupt Soviet Union, this is a dangerous time for Capital to have a crisis and all Communists should be supporting it. We can win the odd skirmish, but the present network-based re-emerging forces of opposition are untested against a populist push towards Fascism. The Chinese government isn't looking for a revolt, they already won that one. Exactly so, with some tiny reservation about whether it might have been a pyrrhic victory. Hence the uncomfortably risky creation of a quasi-capitalist driver for industrial progress. Piffle. They discovered profit works. No. Take a glimpse of Marx's "Capital". Scan "The Communist Manifesto". Many communists at the time of China's revolution refused to recognise it as a socialist state. Same with the Russian revolution. The hammer and sickle is an emblem of desperate hope, because they do not provide the conditions for socialism. Agricultural labour was already organised but lacking industrial technology, and there were few industrial workers. Socialism requires organisation on an industrial scale, so the best they could do at the outset was collectivise the farms. That tended to block the transition to industrial manufacture, without improving the farms enough to match the economic progress of Capitalism. All Communists knew these problems from the start. We supported those states on the grounds that they had no alternative at the time, and all we could do is hope for the best. China is deep in unchartered waters, but it's got to be done. Nobody wants to end up in the final form of human organisation without an iphone. They're banking on 'controlling' it. The West is betting on a 'reverse Marx' effect. Don't quite know what you mean, but it sounds like the truth. Let's all hope the CP of China continues to grapple heroically. Without Communists, the risk of Fascism is much greater. In case it has escaped your notice (it must certainly escape the Butcher's), many of the enjoyable aspects of the liberal democracies we love are disappearing fast. And which ones are those? 'Freebies'? Yes. The ones that multiply your resources compared to those of a disorganised rabble. And no, the freedoms that you hold dear, that ordinary people like you and me suffered and fought and in many cases died for. Our states just don't work without growth. States work just fine without growth. It's people that want it. 'Growth' is what makes it possible to 'grow' from living in a one horse one room log cabin to a 2 car 3 bedroom house/apartment with sewer, running water, central heat, and a wide screen TV. Yes, of course, and Capitalism drives it by necessity, not whim. That's why it's a pre-requisite for Socialism. In total, workers cannot be paid enough today to buy all of today's produce. There would be no surplus, and hence nothing for Capital to appropriate. No profit, no Capitalism. So who buys the extra stuff? As long as Capitalism is growing there are ways out of the problem such as expansion (where sales are made outside the system) or inflation (where labour is paid enough to buy what it produced yesterday) or increases in productivity (same result say some but not necessarily so say I). Each of these mechanisms is inclined to lead to crises of overproduction (wrongly corrected to "crises of underconsumption" by many Pinko Socialists). The running adjustments made by Capital to correct itself are often unpleasant, and occasionally have led to hyperinflation and the mass destruction of production facilities through war. As every good Communist knows, if we're not moving forwards, we're slipping backwards. A 'good communist' wants not these things (Yoda). No more the freedom of travel for the majority. No more the freedom of owning a house, borrowing money to start a business, buying a new car. We were free to stop making things. The U.S. is neitherChinanor Europe... yet. The signs are not encouraging. Our financial institutions were free to invest our dwindling surplus product in...China. Ha ha, we thought...and still think in so many cases...let's take advantage of those poor downtrodden cheap labourers. Speak for yourself. All of Europe and America have been guilty of trying to exploit the Chinese people. Exploitation is what we're good at. Let's hope the boot doesn't end up on the other foot. Chinese labour has not been cheap when you take into account the social costs of providing for the startling progress of its productivity. A significant proportion of the investment in that progress was from our liberal democracies. Consequently, by sleight of the invisible hand of capital, we oweChina****loads of stuff. It isn't because of 'capital'. They're getting a return on the investment. In Capitalism, investments *are* capital. Then we gobbled up everything we could get our hands on fromChinabecause we loved exploiting that cheap labour. Speak for yourself. Doesn't America have an imbalance of trade with China? Consequently we oweChina ****loads more stuff. Unfortunately, and especially in the case of Britain, we've stopped making stuff. We've even largely stopped digging stuff up, and have lost or abandoned many of the places we dug in anyway. As Margaret Thatcher warned, sooner or later you run out of someone else's money. Your banks and mine are running us out of money and giving it to someone else. The defining feature of the success of Chinese labour is not its cheapness, but the epic scale and effectiveness of its organisation. I remember enthusing here about the Beijing Olympic ceremony...about the stunning co-ordination of so many performers, and about the speech from the General Secretary of the Communist Party, in which he announced the GreenChinainitiative. Was that before or after they said you can shove Kyoto up your EU? Pot, kettle. They were driven out, I seem to remember, by a deliberate American ploy to be totally unreasonable and demand a halt to Chinese industrial progress. China has since demonstrated that, good to its word, it is fully committed to the objectives of accords, but can't accept terms that would cripple emerging economies. Per person, their consumtion and emmisions are a fraction of those of Americans. Just a couple of years after the US said it couldn't afford to letChinatake the lead in the alternative energy market, You might as well quote Bugs Bunny as Obama, for all it's worth. But he is elected by your beloved liberal democracy. Don't you respect it? Say that in China and there'll be a tank outside your door within the hour. Chinais building wind farms in the US. Take any industrial sector you like and the story is much the same. No, but it's too complex to go into here. Of course. It is true that America still makes some things, and so does parts of Europe. Britain is short on quantity for sure, and it is by no means certain that Capital will continue to pay us for hosting its chicanery. Recovery shouldn't be impossible but there are very serious risks. China is on our side of whatever solution there may be, and carping really is counter productive. Generally speaking the Chinese people are very proud of their creation, and much of the apparent grumpiness is impatience, not condemnation. Things were so bad for so long, they know they've done well to get this far. Wake up. Blink. Consider the true value of labour rather than its cheapness. The value of labor is what someone is willing to pay, just as that's the value of anything else. I don't think many economists have ever held such an extreme view. The price is what people are willing to pay. The difference between price and value is profit, broadly speaking. One reason your formulation is unacceptable is that it considers labour to be a commodity, which is obviously inhumane. Wage labour employs the whole man, freedom and all, for much of the time. A commodity has no liberty. The value of Chinese labour is supported by the raw materials that our capital abandoned, it is multplied by a level of organisation that we never achieved even when we tried hard, and it is further multiplied by its tooling and its adaptable infrastucture. The Egyptians were good at building things too. Totalitarianism and slave labor can be efficient, if you're ruthless enough. Or at least so it seems because everyone but you is 'paying' for it. Totalitarianism has been extremely effective but like any state of Capitalism it needs to grow. Thankfully the Communists were there to stop it, although sadly we lost in Spain. p We go through this nonsense every time some totalitarian regime appears to 'do well'. Everyone was fawning over the NAZI 'economic miracle' and then hand wringing over the Soviet Union "winning the space race," at the same time they were building a barbed wire machine gun armed wall around the whole thing to keep their people from escaping. Communists have never been fooled by the "totalitarian" inclinations of Capital in crisis. If like me you grew up with Orwell or the like at school, you should check out the distinction between Fascism and Socialism (as defined by Communists) more seriously because he knew bugger all and was an imperialist poodle for sure. Even the liner notes of my CD of Shostakovich's "Leningrad" tells me it's about Stalin. Like as if the composer wasn't just a few miles from approaching Panza divisions. Both are philisophically founded on Hegel's "Phenomenology of Spirit", being the endpoint of dialectical idealism. Communism sees the central dialectic to arise between classes, with the working class eventually subsuming the owners of the means of production. Fascism is about state and race, and imagines the victors to be the chosen people of a land destined to lead the world. Zionism is a modern but thankfully not dominant example. Both end up with a single party, but Fascism is a form of capitalism and so requires no revolution because it retains the class dynamic, removing much of the freedom-sharing by force of arms. No, thank you. I have no desire to push stones for the Pharaoh, *or* the State. Of course not. Neither do I. Not even the few we must push now. Like it says in the Communist Manifesto, "A spectre looms over Europe, the spectre of communism". You need to wrest control over your state before it grabs all your freedom for itself. You need to be far better organised to fight the battles to come. Our tooling is on rusty scrapheaps, and we don't have enough resources to invest in infrastructure. That's because the money was extracted from the private sector and spent on other things. It's not about money in the end. It's about real consumable resources. Having appropriated your surplus, Capital has invested much of it elsewhere, and it's still doing it as fast as it possibly can. It is not investing in your productivity anywhere near as much as it did, so you produce less, so you get poorer. You all need to pull your socks up and work out what to do with all the over-capacity before it atrophies. Germany excepted, for the moment. So who will be tomorrow's cheap labour? Who risks being tomorrow's cannon-fodder? Who's most likely to find themselves in a brutal dictatorship? When it's up against the wall, capital doesn't do totalitarianism by halves. Stop carping. HelpChinashow the way forward. Better red than dead. Europe, with the U.S. lagging behind, has been trying to 'out socialist' the communists for over half a century but they're burdened by not having the totalitarian guts to roll tanks over their own citizens in the town square.Ian Only Communists have managed to achieve Socialism, and it's still looking fragile. It's a revolutionary step, you can't just drift there. You're thinking of the outcome of Capital's continuing cost- benefit analysis of social provision versus social decay. Wage-serfs can't make cars, much less design them. At times of full employment, Ford discovered that his factories forgot how to operate themselves. Without restraint, we discovered painfully in Europe that Capital abuses its freedom. Without assistance in long-term planning, Capital is apt to forget about things like education, healthcare and public order. It uses unions to manage workers cheaply. For every expansion of the state, Capital had a reason. Europeans aren't daft, they're just more experienced. Common social provisions aren't socialism, they're practical common sense for Capital as long as markets are fully functioning. They can disappear fast. In Europe, unelected administrators are grabbing power on behalf of Capital, and the weak liberal democratic governments are letting them do it to avoid blame for the ensuing pain. All coming your way. This crisis or next. Ian |
|
#35
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Dec 5, 3:12*am, flipper wrote:
On Sun, 4 Dec 2011 00:13:01 -0800 (PST), Patrick Turner wrote: Delete much **** typed at me. Fipper lies with :- I haven't thrown '****' at anyone, that's your specialty. Although, it's hardly unique or an honor as you hurl it at just about every one and every thing. Flipper takes time out to thow **** instead of just building Brook 10C to show us all he knows what he's talking about. Patrick Turner. You're the only one confused so you go build one. You're a stubborn lazy arsole. I shall not do what you need to do yourself. Patrick Turner. |
|
#36
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Thu, 8 Dec 2011 03:15:29 -0800 (PST), Patrick Turner
wrote: On Dec 5, 3:12*am, flipper wrote: On Sun, 4 Dec 2011 00:13:01 -0800 (PST), Patrick Turner wrote: Delete much **** typed at me. Fipper lies with :- I haven't thrown '****' at anyone, that's your specialty. Although, it's hardly unique or an honor as you hurl it at just about every one and every thing. Flipper takes time out to thow **** instead of just building Brook 10C to show us all he knows what he's talking about. Patrick Turner. You're the only one confused so you go build one. You're a stubborn lazy arsole. You're an arrogant jackass to imagine I should trot off and build something just because 'Lord Turner' speaketh. I shall not do what you need to do yourself. I have no problem understanding the patent. Patrick Turner. |
|
#37
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Dec 9, 4:03*pm, flipper wrote:
On Thu, 8 Dec 2011 03:15:29 -0800 (PST), Patrick Turner wrote: On Dec 5, 3:12*am, flipper wrote: On Sun, 4 Dec 2011 00:13:01 -0800 (PST), Patrick Turner wrote: Delete much **** typed at me. Fipper lies with :- I haven't thrown '****' at anyone, that's your specialty. Although, it's hardly unique or an honor as you hurl it at just about every one and every thing. Flipper takes time out to thow **** instead of just building Brook 10C to show us all he knows what he's talking about. Patrick Turner. You're the only one confused so you go build one. You're a stubborn lazy arsole. You're an arrogant jackass to imagine I should trot off and build something just because 'Lord Turner' speaketh. I shall not do what you need to do yourself. I have no problem understanding the patent. Oh yes you DO have a problem. But you think you are 100% infallible, like one of those silly old Popes who burned Bruno at the stake for his *correct* beliefs about the cosmos - and you just cannot ever admit you make a mistake. If you wish to get respect, you have to earn it, and you have not done this yet, and your typed response about the patent is not worth anything and to proove to yourself and the other 2 ppl bothering to read your "I know it all" dumbo posts you have to build the amp and test it properly. You cannot have any respect if you maintain you are right without providing proof. Patrick Turner. |
|
#38
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Fri, 9 Dec 2011 01:00:53 -0800 (PST), Patrick Turner
wrote: On Dec 9, 4:03*pm, flipper wrote: On Thu, 8 Dec 2011 03:15:29 -0800 (PST), Patrick Turner wrote: On Dec 5, 3:12*am, flipper wrote: On Sun, 4 Dec 2011 00:13:01 -0800 (PST), Patrick Turner wrote: Delete much **** typed at me. Fipper lies with :- I haven't thrown '****' at anyone, that's your specialty. Although, it's hardly unique or an honor as you hurl it at just about every one and every thing. Flipper takes time out to thow **** instead of just building Brook 10C to show us all he knows what he's talking about. Patrick Turner. You're the only one confused so you go build one. You're a stubborn lazy arsole. You're an arrogant jackass to imagine I should trot off and build something just because 'Lord Turner' speaketh. I shall not do what you need to do yourself. I have no problem understanding the patent. Oh yes you DO have a problem. Nope and you babbling to the contrary isn't evidence of anything. But you think you are 100% infallible, Gibberish. If I see a pig and you claim it's a goat I still know I's a pig and that has nothing to do with thinking I'm 'infallible', but with observable fact. And when, as just one example, you claim a triode can't rectify I know that's wrong because I can, and did, point to not only your 'bible', RDH4, showing how to do it but multiple commercial examples using them. like one of those silly old Popes who burned Bruno at the stake for his *correct* beliefs about the cosmos - and you just cannot ever admit you make a mistake. If you wish to get respect, you have to earn it, and you have not done this yet, and your typed response about the patent is not worth anything and to proove to yourself and the other 2 ppl bothering to read your "I know it all" dumbo posts you have to build the amp and test it properly. You cannot have any respect if you maintain you are right without providing proof. I've already provided sufficient proof, 'Pope Turner', in the text of the patent, the RDH4 section explaining plate detectors, that you denied exist, several commercial examples of them, and simulations in both solid state and tube. There is no need for me to further 'prove' what was, at the time, common knowledge and can be found even in Wikipedia. On the other hand, your 'evidence' consists of nothing more than 'Pope Turner' hath spoken, the inventor is a liar, because it isn't what 'Pope Turner' hath spoken, and, what you laughingly claim as a 'scientific' argument, "shove it up your ass." The fact of the matter is you, 'Pope Turner', are not keeper of the 'holy word' and no one, including myself, need kiss your ring of sublime arrogance. Patrick Turner. |
|
#39
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
I mentioned to Flipper that ....... But you think you are 100% infallible, And Flipper replies with ....... Gibberish. If I see a pig and you claim it's a goat I still know I's a pig and that has nothing to do with thinking I'm 'infallible', but with observable fact. There is nothing in the rest of Flipper's post admitting he is fallible, which he most certainly is. Everyone knows I am fallible, and when I make a mistake, I tell everyone and move on. But not Flipper. He just will not admit he might not fully understand a Brook 10C bias control circuit. He will NOT spend an hour building a sample output stage equal to a Brook 10C, and instead, bashes us senseless with statements that he's always right, we are stupid, arrogant etc, and that he's not like a fukkin 16th century Pope. Slowly I see his credibility reduce to zero. When is Flipper going to build a Brook 10C to find the truth and tell us all about it in a precise detailed manner which is acceptable? For anyone else interested in the Brook 10C, I suggest they'll only really ever understand how it works, or if it works as the patent says, by building and observing all phenomena. DO NOT BELIEVE WHAT FLIPPER SAYS; IT COULD BE BULL**** !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ! Patrick Turner. |
|
#40
Posted to rec.audio.tubes
|
|||
|
|||
|
Brook 10c servo bias
On Mon, 12 Dec 2011 00:39:39 -0800 (PST), Patrick Turner
wrote: I mentioned to Flipper that ....... But you think you are 100% infallible, And Flipper replies with ....... Gibberish. If I see a pig and you claim it's a goat I still know I's a pig and that has nothing to do with thinking I'm 'infallible', but with observable fact. There is nothing in the rest of Flipper's post admitting he is fallible, which he most certainly is. Everyone knows I am fallible, and when I make a mistake, I tell everyone and move on. When you make a mistake you call people liars. But not Flipper. He just will not admit he might not fully understand a Brook 10C bias control circuit. He will NOT spend an hour building a sample output stage equal to a Brook 10C, and instead, bashes us senseless with statements that he's always right, we are stupid, arrogant etc, and that he's not like a fukkin 16th century Pope. Slowly I see his credibility reduce to zero. When is Flipper going to build a Brook 10C I've never had a hankering to build a 10C, don't now, and probably never will. Unless you want to buy one. Make an offer and I'll consider it. to find the truth and tell us all about it in a precise detailed manner which is acceptable? 'Pope Turner' again pretends he is god's appointed judge of the divinely "acceptable" and everyone must kiss his ring of sublime arrogance. For anyone else interested in the Brook 10C, I suggest they'll only really ever understand how it works, or if it works as the patent says, by building and observing all phenomena. DO NOT BELIEVE WHAT FLIPPER SAYS; IT COULD BE BULL**** !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ! I never asked anyone to 'take my word' for anything and provided the links to the patent, white paper, wikipedia article on plate detectors, RDH4 section explaining their operation, and multiple examples of DIY and commercial products using them. It is you, 'Pope Turner', who makes 'divine declarations' you expect people to take on 'blind faith'. Patrick Turner. |
| Reply |
|
| Thread Tools | |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Forum | |||
| Brook sliding bias operation. | Vacuum Tubes | |||
| Brook amplifiers, sliding bias. | Vacuum Tubes | |||
| More thoughts on servo bias | Vacuum Tubes | |||
| Servo-controlled fixed bias | Vacuum Tubes | |||
| Servo bias schemas at ABSE. | Vacuum Tubes | |||
![Ian Iveson[_2_] is offline](images/SultanThemeVB3R/statusicon/user_offline.gif)
Linear Mode
