[[email protected]]

"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes

[[email protected]]

On May 28, 11:03*am, wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued:http://easyurl.net/TubesTubes

I don't need my amp adding anything to the content. I just want to
hear what was recorded. The fatal flaw in your comment is
"generate". Why should the amp be generating content? A solid state
amp can pass any original harmonic content within human range that is
on the source just as well as a tube amp.

[Dave]

wrote in message
...
On May 28, 11:03 am, wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued:http://easyurl.net/TubesTubes

I don't need my amp adding anything to the content. I just want to
hear what was recorded. The fatal flaw in your comment is
"generate". Why should the amp be generating content? A solid state
amp can pass any original harmonic content within human range that is
on the source just as well as a tube amp.

Lots of folks like the "warm" tube sound. It's a personal preference, akin
to one's choice of speakers. Me, I like both, and have two systems, one
with a tubed amp and one with a solid state.

I will say that tubes sound better to me when being overdriven than solid
state... the distortion they produce seems to be less objectionable to my
subjective ears than that horrible SS noise. Not that that's a reason to
choose one over the other...

[[email protected]]

On May 28, 11:42*am, "Dave" wrote:
wrote in message

...
On May 28, 11:03 am, wrote:

"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued:http://easyurl.net/TubesTubes

I don't need my amp adding anything to the content. *I just want to
hear what was recorded. *The fatal flaw in your comment is
"generate". *Why should the amp be generating content? *A solid state
amp can pass any original harmonic content within human range that is
on the source just as well as a tube amp.

Lots of folks like the "warm" tube sound. *It's a personal preference, akin
to one's choice of speakers. *Me, I like both, and have two systems, one
with a tubed amp and one with a solid state.

I will say that tubes sound better to me when being overdriven than solid
state... the distortion they produce seems to be less objectionable to my
subjective ears than that horrible SS noise. *Not that that's a reason to
choose one over the other...

Warm? Can you quantify it? I think not.

The tube overdrive distortion is intentionally used sometimes by
electric guitar musicians. Someone decided to expand that and make it
a reason to prefer tube amps over solid state. If you're playing an
electric guitar then sure. But if you're playing recorded music then
no, do not overdrive your amp.

[Eeyore]

wrote:

"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes

Well ... if you actually LIKE added distortion !

Graham

[Eeyore]

Dave wrote:

Lots of folks like the "warm" tube sound.

Actually only a miniscule number of people have ever heard it.

Graham

rec.audio.opinion deleted because all you get there are trolls.

[Ian Thompson-Bell]

wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it is triodes alone
that generate pleasing 2nd harmonic distortion. Pentodes generate odd
harmonics just as much as transistors do.

Second the amount of distortion is level dependent. The output stages of
an amp create by far the most distortion. Any push pull amp output stage
will, by definition cancel most of the even order harmonics and leave
many nasty odd harmonics in the output - no better in that respect than
a transistor amp.

So, the ONLY power amp with mainly odd harmonics in its output will be a
triode SET.

Cheers

Ian

[Peter Wieck]

On May 28, 11:03*am, wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued:http://easyurl.net/TubesTubes

Um, this is a troll. And firmly rooted in received wisdom and blind
faith.

As such, no opinions will be made or changed by it, it serves no
useful purpose, and comment upon it merely gives the Original Poster
the attention he/she wants anyway.

Those who prefer tubes will continue to prefer them. Those who enjoy
tubes as another aspect of the Audio Hobby will continue to do so...
and so forth.

Peter Wieck
Melrose Park, PA

[Eeyore]

Soundhaspriority wrote:

"Dave" wrote

I will say that tubes sound better to me when being overdriven than solid
state... the distortion they produce seems to be less objectionable to my
subjective ears than that horrible SS noise. Not that that's a reason to
choose one over the other...
It seems possible to avoid that dilemma. I have never experienced audible
distortion due to overdriving a SS amplifier, because I do not overdrive
them.

Not difficult to achieve either given the simplicity with which SS amps can be
made very high power with no practical likelihood of clipping.

Graham

[Eeyore]

Ian Thompson-Bell wrote:

So, the ONLY power amp with mainly odd harmonics in its output will be a
triode SET.

Or a SS Mosfet design.

Graham

[Richard Crowley]

wrote ...
On May 28, 11:03 am, wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued:http://easyurl.net/TubesTubes

I don't need my amp adding anything to the content. I just
want to hear what was recorded. The fatal flaw in your
comment is "generate". Why should the amp be generating
content? A solid state amp can pass any original harmonic
content within human range that is on the source just as well
as a tube amp.

It was posted by a Google/Gmail troll/spammer who
probably doesn't know a vacuum tube from his left
elbow and isn't likely to return to read any responses.

[Arny Krueger]

wrote in message


"In a word: YES...

"The answer is rooted in the harmonic content that the
device can pass or generate..."

There is no question that tubed power amps are inferior when it comes to
passing harmonic content. They are just too nonlinear and just too limited
in terms of power bandwidth to compare with more modern alternatives.

As far as the generation of harmonic content goes, it is unclear why
maximizing harmonic content would even be desirable in a component of a high
fidelity system. Furthermore, if versatile and powerful harmonic content
generation were desired, then the tools of choice would be from the digital
domain.

[Arny Krueger]

"Ian Thompson-Bell" wrote in
message
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the
device can pass or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it is
triodes alone that generate pleasing 2nd harmonic
distortion. Pentodes generate odd harmonics just as much
as transistors do.

It is a myth that triodes generate only even harmonics. In fact, tubes have
basically exponential response, which leads to the generation of a wide
variety of orders of distortion, both odd and even.

[Tzortzakakis Dimitrios[_2_]]

? ?????? ??? ??????
...
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

No idea, never heard one. I find though, vacuum tube circuits fascinating.
For my thesis, I constructed an AM transmitter with an 6C4 for oscillator,
and a 807 for final stage, class C of course, complete with antenna,
resonating circuit, modulation transformer and 50 W solid state amplifier.



--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr

[RapidRonnie]

On May 28, 2:08 pm, "Arny Krueger" wrote:
wrote in message



"In a word: YES...
"The answer is rooted in the harmonic content that the
device can pass or generate..."

There is no question that tubed power amps are inferior when it comes to
passing harmonic content. They are just too nonlinear and just too limited
in terms of power bandwidth to compare with more modern alternatives.

As far as the generation of harmonic content goes, it is unclear why
maximizing harmonic content would even be desirable in a component of a high
fidelity system. Furthermore, if versatile and powerful harmonic content
generation were desired, then the tools of choice would be from the digital
domain.

Properly designed tube amplifiers have entirely satisfactory bandpass
and distortion characteristics. Passing frequencies above 35-50 kHz is
very undesireable in an audio amplifier. Ideally a shallow taper from
about 25 kHz and a drop at 50 or so is desireable.

Many solid state audio amplifiers work well for RF in the 100-300 kHz
range. That is not a feature, it's a bug. The output transformer of a
tube amplifier beneficially throttles this extreme HF response.

[RapidRonnie]

3. Compared to solid state, tube amps are a pain in the ass. They hum, hiss,
burble, and motorboat, either out of the box, or many years before a SS amp
would be vulnerable to aging components.


Nonsense. Solid state amps fail hard and take speakers with them all
the time. Tube ones rarely do. They are easier for the hobbyist to
troubleshoot.

[Arny Krueger]

"RapidRonnie" wrote in message

3. Compared to solid state, tube amps are a pain in the
ass. They hum, hiss, burble, and motorboat, either out
of the box, or many years before a SS amp would be
vulnerable to aging components.

Nonsense. Solid state amps fail hard and take speakers
with them all the time.

And tubed amps never ever fried speakers? Surely you jest!

Whenever you start talking about accidents, you have to consider the number
of tubed amps versus the number of SS amps. At this point, tubed amps
probably make up less than 0.1% of all amplifiers in use.

Tube ones rarely do.

One reason - tubed amps are themselves quite rare.

They are easier for the hobbyist to troubleshoot.

Those of us who lived through the bad old days of tubes, know that SS amps
are tremendously more reliable.

[Arny Krueger]

"RapidRonnie" wrote in message

On May 28, 2:08 pm, "Arny Krueger"
wrote:
wrote in message



"In a word: YES...
"The answer is rooted in the harmonic content that the
device can pass or generate..."

There is no question that tubed power amps are inferior
when it comes to passing harmonic content. They are
just too nonlinear and just too limited in terms of
power bandwidth to compare with more modern
alternatives.

As far as the generation of harmonic content goes, it is
unclear why maximizing harmonic content would even be
desirable in a component of a high fidelity system.
Furthermore, if versatile and powerful harmonic content
generation were desired, then the tools of choice would
be from the digital domain.

Properly designed tube amplifiers have entirely
satisfactory bandpass and distortion characteristics.

Well, if you say that for a far higher price and considerably greater
inconvenience, it is possible to have a tubed amp with good performance, I'd
have to agree.


Passing frequencies above 35-50 kHz is very undesireable
in an audio amplifier. Ideally a shallow taper from about
25 kHz and a drop at 50 or so is desirable.

If you include the effects of real-world speaker loads, most tubed amps have
audible issues inside the 20-20 kHz range because of their far higher source
impedance.

Good thing you have nothing to say about the low bad performance of tubed
amps, because all but the really expensive and heavy ones do rather more
poorly in the bass.


Many solid state audio amplifiers work well for RF in the
100-300 kHz range.

That's not typical. Everybody knows that ultrasonic response is an open door
for problems with EMI, etc. Most SS amps have artificially sacrificed high
frequency response to enhance their usability.

That is not a feature, it's a bug. The
output transformer of a tube amplifier beneficially throttles this extreme
HF response.

Throttling the HF response of a SS amp only takes one or two penny-cost
capacitors.

But I will give the majority of tubed amps a nod of sorts for their inferior
power bandwidth below 30 Hz.

[RapidRonnie]

3. Compared to solid state, tube amps are a pain in the
ass. They hum, hiss, burble, and motorboat, either out
of the box, or many years before a SS amp would be
vulnerable to aging components.
Nonsense. Solid state amps fail hard and take speakers
with them all the time.

And tubed amps never ever fried speakers? Surely you jest!

It's happened but not to me.


Whenever you start talking about accidents, you have to consider the number
of tubed amps versus the number of SS amps. At this point, tubed amps
probably make up less than 0.1% of all amplifiers in use.

If even that many, but when you consider the percent overall as
restricted to serious hobbyists it's 25% or so.


Tube ones rarely do.

One reason - tubed amps are themselves quite rare.

No, among _high end hobbyists_ they are fairly common.


They are easier for the hobbyist to troubleshoot.

Those of us who lived through the bad old days of tubes, know that SS amps
are tremendously more reliable.

Those of us living in the good new days of tubes have no trouble
keeping them running with some good basic technicianship and the
appropriate tools. We don't need curvetracers, constant current bias
supplies or milling machines to keep them going.

[RapidRonnie]

If you include the effects of real-world speaker loads, most tubed amps have
audible issues inside the 20-20 kHz range because of their far higher source
impedance.

Good thing you have nothing to say about the low bad performance of tubed
amps, because all but the really expensive and heavy ones do rather more
poorly in the bass.

All tube amps are expensive and heavy these days. No one is
advocating them for subwoofer drivers.

Any good push pull 6L6 or 6550 power amp will drive a classic
Klipsch, Altec or JBL setup to higher bass SPLs than any normal person
can tolerate. Headbangers wanting more should move out of town so as
not to disturb the rest of us.

[Trevor Wilson[_2_]]

wrote in message
...
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

**Nonsense. Valves are inherently high frequency devices. As such, they are
easily capable of passing or generating higher order harmonics. There are
more problems with your nonsensical statement. These include:

* The TOPOLOGY can be far more important than the devices used, WRT high
order harmonic generation.
* The use of triodes or pentodes can affect sound quality most profoundly.
* The presence of an output transformer will affect high order harmonic
generation to a greater degree than the type of output device used.

--
Trevor Wilson
www.rageaudio.com.au

[Arny Krueger]

"RapidRonnie" wrote in message


Those of us who lived through the bad old days of tubes,
know that SS amps are tremendously more reliable.

Those of us living in the good new days of tubes have no
trouble keeping them running with some good basic
technicianship and the appropriate tools.

Plan B - use SS amps which generally just run and run and run.

We don't need curvetracers,

Never did, for SS.

constant current bias supplies

Don't make sense for tubes since their properties are a moving target.

or milling machines

?????????????/

to keep them going.

If you call what the typical tubed amp does, "going".

[jamesgangnc]

"RapidRonnie" wrote in message
...


If you include the effects of real-world speaker loads, most tubed amps
have
audible issues inside the 20-20 kHz range because of their far higher
source
impedance.

Good thing you have nothing to say about the low bad performance of tubed
amps, because all but the really expensive and heavy ones do rather more
poorly in the bass.

All tube amps are expensive and heavy these days. No one is
advocating them for subwoofer drivers.

Any good push pull 6L6 or 6550 power amp will drive a classic
Klipsch, Altec or JBL setup to higher bass SPLs than any normal person
can tolerate. Headbangers wanting more should move out of town so as
not to disturb the rest of us.

Tubes are inherently bad devices to drive a low impedance load where as
solid state is perfectly happy being coupled directly to a speaker. You
can't make a tube current amp and that's what you need for audio.

[Ian Thompson-Bell]

Eeyore wrote:

Ian Thompson-Bell wrote:

So, the ONLY power amp with mainly odd harmonics in its output will be a
triode SET.

Or a SS Mosfet design.

Graham


Yes, they have a very similar transfer function to triodes.

Cheers

Ian

[Ian Thompson-Bell]

flipper wrote:
On Wed, 28 May 2008 17:34:05 +0100, Ian Thompson-Bell
wrote:

wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes

There is a lot missing from this article.

Yes, as well as full of 'opinion'. There's not a single measurement in
it.

First, it is triodes alone
that generate pleasing 2nd harmonic distortion.

No, you're confusing SE with PP.


No, I was being inaccurate! I should have said triodes generate a larger
proportion of second harmonic compared to higher ones than either
pentodes of BJTs.

Pentodes generate odd
harmonics just as much as transistors do.

No and it's misleading to speak of simply 'odd' harmonics. It's the
higher order harmonics that are harsh and then there's the issue of
the harmonic mix.

Hmm, the ratio of 3rd (and higher odd harmonics) to 2nd harmonic
distortion in pentodes is greater than in triodes because of the
different transfer function.


All of which smacks a bit of voo-doo because, according to
measurements, they're all below 'audible' and so, in theory, should be
of no consequence. But then, and again according to measurements, THD
that's 'inaudible' (or at least unoffensive) in a tube amp offends
like nails on a blackboard in SS amps so an SS amp *must* have lower
THD figures to be tolerable.


The danger here of course is that measuring THD alone is not sufficient.

Second the amount of distortion is level dependent. The output stages of
an amp create by far the most distortion. Any push pull amp output stage
will, by definition cancel most of the even order harmonics

Which includes triodes.

Indeed.


and leave
many nasty odd harmonics in the output - no better in that respect than
a transistor amp.

No.

Which bit is not correct the whole or just the latter part?


So, the ONLY power amp with mainly odd harmonics in its output will be a
triode SET.

Judging from the rest you apparently mean "even harmonics" but what
does "mainly" mean?

Yes, mixing my odds and evens again.


Cheers

Ian

[Ian Thompson-Bell]

Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the
device can pass or generate..."

Continued: http://easyurl.net/TubesTubes

There is a lot missing from this article. First, it is
triodes alone that generate pleasing 2nd harmonic
distortion. Pentodes generate odd harmonics just as much
as transistors do.

It is a myth that triodes generate only even harmonics. In fact, tubes have
basically exponential response, which leads to the generation of a wide
variety of orders of distortion, both odd and even.



No, pentodes have an exponential transfer function like BJTs do, but
triodes have a simpler ^3/2 transfer function which produces a different
harmonic content.

Cheers

Ian

[Trevor Wilson[_2_]]

"RapidRonnie" wrote in message
...


3. Compared to solid state, tube amps are a pain in the ass. They hum,
hiss,
burble, and motorboat, either out of the box, or many years before a SS
amp
would be vulnerable to aging components.


Nonsense. Solid state amps fail hard.

**Some do, but if you install a distortion producing, phase shifting output
transformer between output devices and load (like most valve amps) then the
problem is solved.

and take speakers with them all
the time.

**Incorrect. Many solid state amps employ sophisticated protection systems
to prevent this from happening. Then, of course, one could employ an output
transformer.

Tube ones rarely do.

**Largely because they have a distortion producing, phase shifting output
transformer, between load and output devices.

They are easier for the hobbyist to
troubleshoot.

**That much may well be true, depending on the topology. Fortunately for
hobbyists, solid state amps tend to be vastly more reliable.

--
Trevor Wilson
www.rageaudio.com.au

[Trevor Wilson[_2_]]

"Ian Thompson-Bell" wrote in message
...
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it is triodes alone that
generate pleasing 2nd harmonic distortion. Pentodes generate odd harmonics
just as much as transistors do.

**So much nonsense, so little time to correct it. Why this myth continues to
be perpetrated is a complete mystery. The TOPOLOGY dictates what type of
harmonics are generated, not the devices. Push pull eliminates even order
distortion products. Valve or solid state.


Second the amount of distortion is level dependent. The output stages of
an amp create by far the most distortion. Any push pull amp output stage
will, by definition cancel most of the even order harmonics and leave many
nasty odd harmonics in the output - no better in that respect than a
transistor amp.

**Nonsense.


So, the ONLY power amp with mainly odd harmonics in its output will be a
triode SET.

**Nonsense. Where you do you get this nonsense from?


--
Trevor Wilson
www.rageaudio.com.au

[Norman M. Schwartz]

RapidRonnie wrote:
3. Compared to solid state, tube amps are a pain in the ass. They
hum, hiss, burble, and motorboat, either out of the box, or many
years before a SS amp would be vulnerable to aging components.


Nonsense. Solid state amps fail hard and take speakers with them all
the time. Tube ones rarely do. They are easier for the hobbyist to
troubleshoot.

Good tubes, their matched pairs, etc. are expensive and not easy to find.
Useful individual tube life is a variable. Many listeners are constantly
concerned, listening for signs of their wear, buy and stock replacement
tubes, spend their listening time listening to the tubes, comparing the
sound of various tubes, their manufacturer, and then very model of a "6550"
etc, etc.) rather than the music. Most often tube amps generate more heat,
than their SS counterparts, and _may_ require the use of noise producing
fans and extensive ventilation. One shouldn't choose to stack other
equipment above them, and eventually self-destruct because of the heat they
generate. Caged or uncaged their heat is a threat to pets and young
children.In the end analysis their characteristic sound has to be a mix of
the nature of the tubes employed and the amp itself.

[Trevor Wilson[_2_]]

"RapidRonnie" wrote in message
...
On May 28, 2:08 pm, "Arny Krueger" wrote:
wrote in message



"In a word: YES...
"The answer is rooted in the harmonic content that the
device can pass or generate..."

There is no question that tubed power amps are inferior when it comes to
passing harmonic content. They are just too nonlinear and just too
limited
in terms of power bandwidth to compare with more modern alternatives.

As far as the generation of harmonic content goes, it is unclear why
maximizing harmonic content would even be desirable in a component of a
high
fidelity system. Furthermore, if versatile and powerful harmonic content
generation were desired, then the tools of choice would be from the
digital
domain.

Properly designed tube amplifiers have entirely satisfactory bandpass
and distortion characteristics. Passing frequencies above 35-50 kHz is
very undesireable in an audio amplifier. Ideally a shallow taper from
about 25 kHz and a drop at 50 or so is desireable.

**Bull****. Such a poor frequency response, will lead to a severely and
audibly compromised phase response. The human ear is very sensitive to phase
problems. A linear frequency response, which leads to a close to 0 degree
phase shift at 20kHz is desirable.


Many solid state audio amplifiers work well for RF in the 100-300 kHz
range. That is not a feature, it's a bug. The output transformer of a
tube amplifier beneficially throttles this extreme HF response.

**Bull****. The output transformer damages the frequency response of valve
amps. Valves are inherently high frequency devices.


--
Trevor Wilson
www.rageaudio.com.au

[Eeyore]

Ian Thompson-Bell wrote:

Eeyore wrote:
Ian Thompson-Bell wrote:

So, the ONLY power amp with mainly odd harmonics in its output will be a
triode SET.

Or a SS Mosfet design.

Yes, they have a very similar transfer function to triodes.

I've designed a few over the years. The last one was ultra-low THD (0.003% @ 1
kHz) but an Audio Precision test set was able to see it and it appeared for all
practical purposes to be near as dammit pure second harmonic. For whatever
reasons it also sounded utterly lovely.

Graham

[Trevor Wilson[_2_]]

"flipper" wrote in message
...
On Thu, 29 May 2008 09:01:52 +1000, "Trevor Wilson"
wrote:



"Ian Thompson-Bell" wrote in message
...
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can pass
or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it is triodes alone
that
generate pleasing 2nd harmonic distortion. Pentodes generate odd
harmonics
just as much as transistors do.

**So much nonsense, so little time to correct it. Why this myth continues
to
be perpetrated is a complete mystery. The TOPOLOGY dictates what type of
harmonics are generated, not the devices.

Well, you're half right. They both dictate the harmonics.

**I am 100% correct. Topology is the factor. Not the devices. Of course,
various devices DO contribute different distortion amounts. For instance:

* At low bias currents, pentodes add large amounts of distortion.
* At low bias current, triodes add smaller amounts of distortion.
* At low bias currents, MOSFETs add very large amounts of distortion.
* At low bias currents, BJTs add smaller amounts of distortion.


Push pull eliminates even order
distortion products. Valve or solid state.

But does nothing for the odd orders, which are dictated by the
devices.

**Sure. ALL amplifiying devices add odd order distortion. At moderate bias
currents, the approximate order is (from best to worst):

BJTs
Triodes
Pentodes
MOSFETs

At high bias currents, the order shifts somewhat to:

BJTs
MOSFETs
Triodes
Pentodes

It is the TOPOLOGY which dominates the issue of distortion production,
however. Depending on the amount of feedback employed, the devices used
makes little difference.

--
Trevor Wilson
www.rageaudio.com.au

[Arny Krueger]

"Ian Thompson-Bell" wrote in
message
Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the
device can pass or generate..."

Continued: http://easyurl.net/TubesTubes

There is a lot missing from this article. First, it is
triodes alone that generate pleasing 2nd harmonic
distortion. Pentodes generate odd harmonics just as much
as transistors do.

It is a myth that triodes generate only even harmonics.
In fact, tubes have basically exponential response,
which leads to the generation of a wide variety of
orders of distortion, both odd and even.

No, pentodes have an exponential transfer function like
BJTs do, but triodes have a simpler ^3/2 transfer
function which produces a different harmonic content.

In my book, what you call ^3/2 transfer function is just another flavor of
exponential.

A ^3/2 transfer function can be read as the square root of cubed, which is
nothing like pure even order or pure second order.

[Arny Krueger]

"Ian Thompson-Bell" wrote in
message
wrote:

So, the ONLY power amp with mainly odd harmonics in its
output will be a triode SET.

No, if you want mainly odd harmonics, you do something symmetrical, like
push-pull.

[Mr.T]

"Dave" wrote in message
news:z3f%j.232$i74.144@edtnps91...
I will say that tubes sound better to me when being overdriven than solid
state... the distortion they produce seems to be less objectionable to my
subjective ears than that horrible SS noise.

And of course a tube amp is likely to be overdriven, generally being of
relatively low power output, whereas a solid state amp should never need to
be overdriven in the first place, with large power outputs available at
relatively low cost. (or extremely low cost when compared to most tube
amps!)

MrT.

[Mr.T]

"Eeyore" wrote in message
...
Lots of folks like the "warm" tube sound.

Actually only a miniscule number of people have ever heard it.

Maybe a small number of *young* people perhaps. The number of older people
who have heard tube equipment is hardly "miniscule"!

MrT.

[Trevor Wilson[_2_]]

"flipper" wrote in message
...
On Thu, 29 May 2008 09:56:14 +1000, "Trevor Wilson"
wrote:



"flipper" wrote in message
. ..
On Thu, 29 May 2008 09:01:52 +1000, "Trevor Wilson"
wrote:



"Ian Thompson-Bell" wrote in message
...
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the device can
pass
or generate..."

Continued: http://easyurl.net/TubesTubes


There is a lot missing from this article. First, it is triodes alone
that
generate pleasing 2nd harmonic distortion. Pentodes generate odd
harmonics
just as much as transistors do.

**So much nonsense, so little time to correct it. Why this myth
continues
to
be perpetrated is a complete mystery. The TOPOLOGY dictates what type
of
harmonics are generated, not the devices.

Well, you're half right. They both dictate the harmonics.

**I am 100% correct.

No, you're not.

Topology is the factor.

It's one factor.

**It is, by far, the major factor. It swamps any influences by the output
devices. Take away global NFB, for instance, and differences between devices
is more readily apparent.


Not the devices.

B.S.

**Keep dissagreeing all you wish. You'll still be wrong.


Of course,
various devices DO contribute different distortion amounts.

And different harmonic distributions as well.

**All of which is swamped by topology differences.



For instance:

* At low bias currents, pentodes add large amounts of distortion.
* At low bias current, triodes add smaller amounts of distortion.
* At low bias currents, MOSFETs add very large amounts of distortion.
* At low bias currents, BJTs add smaller amounts of distortion.


Push pull eliminates even order
distortion products. Valve or solid state.

But does nothing for the odd orders, which are dictated by the
devices.

**Sure. ALL amplifiying devices add odd order distortion.

Yes, but with different distributions.

**All of which is swamped by different topologies.


At moderate bias
currents, the approximate order is (from best to worst):

BJTs
Triodes
Pentodes
MOSFETs

At high bias currents, the order shifts somewhat to:

BJTs
MOSFETs
Triodes
Pentodes

Except for BJTs being the worst of the lot under all conditions that's
not too terribly screwed up.

**Wrong. Modern BJTs are, by far, the most linear output devices available.
Look at the Hfe vs. Ic curve of this device:

http://www.datasheetcatalog.org/data...shiba/3228.pdf

A VERY linear (low distortion) device over a very wide range of currents.
It's PNP complement is similarly low distortion.



It is the TOPOLOGY which dominates the issue of distortion production,
however.

Wrong.

**Don't be silly. Compare SE to PP. Compare zero global NFB to high global
NFB topologies.


Depending on the amount of feedback employed, the devices used
makes little difference.

Also wrong.

**Here's where I get to say: PROVE IT.


--
Trevor Wilson
www.rageaudio.com.au

[jakdedert]

Soundhaspriority wrote:
snip
It seems possible to avoid that dilemma. I have never experienced audible
distortion due to overdriving a SS amplifier, because I do not overdrive
them.

Boy, that one really sets my bull**** detector off! You've NEVER heard
distortion...in your life? Never heard an overdriven car stereo, or AM
radio? Never wanted to get 'just a little more' out of a system and
went a little too far before you backed off? Never been surprised by
unexpectedly loud passage in a piece, which drove your system into
clipping? Ever?

Right....

jak
Bob Morein
(310) 237-6511

[Ian Thompson-Bell]

Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:
"In a word: YES...

"The answer is rooted in the harmonic content that the
device can pass or generate..."

Continued: http://easyurl.net/TubesTubes
There is a lot missing from this article. First, it is
triodes alone that generate pleasing 2nd harmonic
distortion. Pentodes generate odd harmonics just as much
as transistors do.
It is a myth that triodes generate only even harmonics.
In fact, tubes have basically exponential response,
which leads to the generation of a wide variety of
orders of distortion, both odd and even.

No, pentodes have an exponential transfer function like
BJTs do, but triodes have a simpler ^3/2 transfer
function which produces a different harmonic content.

In my book, what you call ^3/2 transfer function is just another flavor of
exponential.


I sujggest you get a better book.

A ^3/2 transfer function can be read as the square root of cubed, which is
nothing like pure even order or pure second order.


A simple expansion shows that the even order terms dominate. See any
book on tubes for details.

Cheers

Ian

[Ian Thompson-Bell]

Arny Krueger wrote:
"Ian Thompson-Bell" wrote in
message
wrote:

So, the ONLY power amp with mainly odd harmonics in its
output will be a triode SET.

No, if you want mainly odd harmonics, you do something symmetrical, like
push-pull.



NO, PP CANCELS odd harmonics.

Cheers