Two mini pre-amps that could be used for portable recording:

http://www.soundprofessionals.com/c.../item/SP-PREAMP

and

http://www.reactivesounds.com/spa2.php


About the same price. Some feature comparisons:

The SP pre-amp has the size advantage, important for portable, stealth
recording. Both small and pocketable, but the Reactive PA is more than an
inch longer than the SP. (Other dimensions similar, Reactive even slightly
thinner. But significantly longer!)

But the Reactive PA ("Boost Box") looks like it has some other advantages.
Most notably, the clipping light. Since the H120 (mp3 player that records)
has no level meters, setting the gain and level on a pre-amp is normally
just guesswork, which I assume would occur with the SP PA. With the Reactive
unit, though, the directions say that you set it to lowest gain, then slowly
turn up the gain until the clipping light starts to light, then back off a
little. Also--simpler controls on the Reactive PA. Besides on/off, just one
continuous rotary dial to control gain.

The SP PA, on the other hand, has a three position switch for gain (0db,
29db, and 50 db), and a rotary dial for "level". (Could someone please
explain the difference between "gain" and "level"? Sorry for the newbie
question.) (The 0 db setting gives no pre-amp function at all, I guess then
functioning like a battery box, the 50 db setting is probably too high for
most uses, so I would guess most users leave the gain setting to 29db, and
do fine setting with the rotary level dial.

The Reactive web site states that it is much better for the rotary
(continuous) dial to control "gain", as theirs does, rather than "level", as
the SP does. What do those reading who understand "gain" and "level" think
of that statement? True? In any case, it certainly looks simpler to
set--just one rotary dial to set, using the clipping light for guidance.
With the SP PA you have to set the three way gain switch, and the rotary
level dial, and if you have no level meter, those two settings have to be
guessed.

I guess I'm leaning towards the Reactive Sounds "Boost Box", although I like
the smaller size of the SP PA. However, I am not too knowledgeable about
this stuff, and perhaps one of you could understand more of the specs of
these two units than I can. If someone has actually tried both and could
compare them, that would be great!

Any comments on comparing those two mini battery pre-amps--Sound
Professionals and Reactive Sounds, would be well-appreciated.

"MS" writes:

Any comments on comparing those two mini battery pre-amps--Sound
Professionals and Reactive Sounds, would be well-appreciated.

The only problem I have with your analysis is the usefulness of the
REactive's clipping light. It MIGHT be useful, but there's a big
"if" in there. If the clipping level that indicates is anywhere near
the clipping level of your particular unit, then it might add value.
Without level meters on the recorder, it's all about experimenting and
knowing the settings still, clip light or no. At least you'll know
when you're clipping your preamp itself though, which I guess is
pretty good.

At any rate, I say some words in detail about the SP preamp and
preamped mic as I use them in my open air recording setup for live
music. Some links to stuff recorded with it are included (look for
the ones that say they were recorded with the NJB):

http://toddh.net/music/njb/

Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | "4 lines suffice."

"MS" writes:

"Todd H." wrote in message
...

At any rate, I say some words in detail about the SP preamp and
preamped mic as I use them in my open air recording setup for live
music. Some links to stuff recorded with it are included (look for
the ones that say they were recorded with the NJB):

http://toddh.net/music/njb/

Todd,

I looked at your site. Much interesting info. Thank you.

One question, however. I notice that all the products you mention (other
than the NJB itself) are from Sound Professionals. I also notice that the
links to those products from your web page have your name (toddh) in the
URL. Do you work for SP? Do you get some kind of commission or credits
toward product purchase when someone makes a purchase from SP, getting to
their site through the referral from yours?

I'm not criticizing, just asking for disclosure.

If you read to the bottom of the page you see the disclosure. 8-)


Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | "4 lines suffice."

Is there any way to test how the clipping level of the Reactive PA compares
with that of the recorder?

In any case having some indication of level, if one has a recorder that has
no level meters at all, might be better than having none at all. (I guess if
the R-PA shows clipping earlier then the recorder would, for example, one
could set it so that it indicates just a little clipping, etc. It would be
good if there were a way to determine how close the clipping light on the PA
compared to what would actually clip on the recorder.

"Todd H." wrote in message
...
"MS" writes:

Any comments on comparing those two mini battery pre-amps--Sound
Professionals and Reactive Sounds, would be well-appreciated.

The only problem I have with your analysis is the usefulness of the
REactive's clipping light. It MIGHT be useful, but there's a big
"if" in there. If the clipping level that indicates is anywhere near
the clipping level of your particular unit, then it might add value.
Without level meters on the recorder, it's all about experimenting and
knowing the settings still, clip light or no. At least you'll know
when you're clipping your preamp itself though, which I guess is
pretty good.

At any rate, I say some words in detail about the SP preamp and
preamped mic as I use them in my open air recording setup for live
music. Some links to stuff recorded with it are included (look for
the ones that say they were recorded with the NJB):

http://toddh.net/music/njb/

Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | "4 lines suffice."

"Julian" wrote in message
...

MS wrote:

The SP PA, on the other hand, has a three position switch for gain (0db,
29db, and 50 db), and a rotary dial for "level". (Could someone please
explain the difference between "gain" and "level"?

Julian wrote:

You immediately answer your question:

No I didn't. (Rest of quote of my previous message, that Julian is referring
to, appears below this message, and more of his response.) Yes, I said that
it looks like one would leave the three positions gain switch (on the SP)
set to one place, and use the rotary continuous level dial for fine-tuning
it.

However, as I said, the Reactive PA has no gain multi-position switch, only
a continuous rotary dial. But in this case the continuous rotary dial
controls gain itself, which they (Reactive) asserts is much better, than
having the rotary dial control level, as the SP PA does.

Therefore, my question was not whether a rotary dial is used for fine
tuning, which is rather obvious, but what is actually the difference between
gain and level, and is there really an advantage (as Reactive asserts) in
having the rotary dial control gain rather than level?

I also mentioned that it seemed simpler to have the one control of the
Reactive rather than the two of the SP. If the one control was only the
three-position gain switch, with no rotary dial (like the Church Audio PA),
I'd consider that a distinct disadvantage, with no possibility of
fine-tuning the setting, just three settings to choose from. But with the
one setting being a continuous rotary dial, controlling gain directly, that
might be preferable. I really don't know, just asking.

You write: "If the knob (rotary level dial on SP PA) increases level or
decreases it from the preset gain switch..........".

Which does it do---increase or decrease? I have seen no documentation that
explains it. Anyone know?



MS wrote:

The 0 db setting gives no pre-amp function at all, I guess then
functioning like a battery box, the 50 db setting is probably too high
for
most uses, so I would guess most users leave the gain setting to 29db,
and
do fine setting with the rotary level dial.


Julian wrote:

If the knob increases level or decreases it from the preset gain
switch then you could fine tune each setting. If you wanted less than
29 dB gain, setting the switch to zero and using the level knob might
do it. Probably 29 will be a most usual setting, but If you are
recording bird calls or something really really quiet you'll want the
full 50 dB and then some. You get the basic idea, and all 3 switch
settings can be useful.

Julian

One thing I notice now, in looking at specs. The gain on the Reactive PA is
adjustable (via the rotary dial) from 0 to 36.5 db. Therefore, it does not
go as high as the 50 db setting on the SP PA. I greatly doubt I would ever
need more than 36.5 db gain though. (For someone who would though, the SP
would be a better choice.)

The SP lists a higher signal to noise ratio than the Reactive. I'm not sure
how accurate those specs are though, whether one manufacturer might measure
it different than another, and whether that might make a difference that one
could actually hear. If anyone knows more about this and other specs, please
share your knowledge about it.

"Todd H." wrote in message
...

At any rate, I say some words in detail about the SP preamp and
preamped mic as I use them in my open air recording setup for live
music. Some links to stuff recorded with it are included (look for
the ones that say they were recorded with the NJB):

http://toddh.net/music/njb/

Todd,

I looked at your site. Much interesting info. Thank you.

One question, however. I notice that all the products you mention (other
than the NJB itself) are from Sound Professionals. I also notice that the
links to those products from your web page have your name (toddh) in the
URL. Do you work for SP? Do you get some kind of commission or credits
toward product purchase when someone makes a purchase from SP, getting to
their site through the referral from yours?

I'm not criticizing, just asking for disclosure.

Oh, you ask what is the difference between "Gain" and "level" controls.

Generally you have one of a few different designs, I can't do ascii
drawing on usenet due to the lack of mono-space fonts guarentee so I do
what call Line graphs instead

One design Mic in------ Control---- Pre-amp---Line out
Another Mic in------ pre-amp----- control----- line out

In either of these cases the GAIN of the pre-amp is fixed, the control
is a LEVEL control, note, that the 2nd one is much better than the first

Yet another design
Mic in------------(pre [control] amp) ----- line out

Note that in this case teh control is PART of the pre-amp, it's a gain
control If I were drawing it Well, try this

Draw a triangle, isoleases Left side vertical, point to the right

This is labeled "Pre-amp"

Now draw a line from the left to a spot about 1/4 the way down from the
top of the vertical (left) side of the amp, it's labeled "MIC IN"

Now draw a line from the point on the right to a label LINE OUT

Now draw a line straight down this line comes down, does a hard right
and ends in an arrow point, Now draw another line, Wavey like
/\/\/\/\/\ this, only vertical, just touching the arrow. a line

It is marked "Gain Control"

What this does is actually vary the GAIN of the pre-amp

The reason that adjustable gain is better is this....

Hi gain amps such as most microphone pre-amps tend to introduce a bit of
noise (Usually a hiss like sound) and if you lower the gain you greatly
lower the additional nosie, But if you lower the OUTPUT with a level
control, all you do is lower everything, sound AND noise

So, if you turn the LEVEL down 1/2, then the noise is reduced 1/2

But if you turn the GAIN down 1/2, then the noise may be reduced to 1/4
or even 1/16th what it was

Ok, that is on paper... In practice... When you start turning down the
gain or level, it don't much matter cause the sound (Desired sound)_ is
loud enough to bury the noise anyway

MS wrote:
"Julian" wrote in message
...

MS wrote:


The SP PA, on the other hand, has a three position switch for gain (0db,
29db, and 50 db), and a rotary dial for "level". (Could someone please
explain the difference between "gain" and "level"?


Julian wrote:


You immediately answer your question:


No I didn't. (Rest of quote of my previous message, that Julian is referring
to, appears below this message, and more of his response.) Yes, I said that
it looks like one would leave the three positions gain switch (on the SP)
set to one place, and use the rotary continuous level dial for fine-tuning
it.

However, as I said, the Reactive PA has no gain multi-position switch, only
a continuous rotary dial. But in this case the continuous rotary dial
controls gain itself, which they (Reactive) asserts is much better, than
having the rotary dial control level, as the SP PA does.

Therefore, my question was not whether a rotary dial is used for fine
tuning, which is rather obvious, but what is actually the difference between
gain and level, and is there really an advantage (as Reactive asserts) in
having the rotary dial control gain rather than level?

I also mentioned that it seemed simpler to have the one control of the
Reactive rather than the two of the SP. If the one control was only the
three-position gain switch, with no rotary dial (like the Church Audio PA),
I'd consider that a distinct disadvantage, with no possibility of
fine-tuning the setting, just three settings to choose from. But with the
one setting being a continuous rotary dial, controlling gain directly, that
might be preferable. I really don't know, just asking.

You write: "If the knob (rotary level dial on SP PA) increases level or
decreases it from the preset gain switch..........".

Which does it do---increase or decrease? I have seen no documentation that
explains it. Anyone know?



MS wrote:

The 0 db setting gives no pre-amp function at all, I guess then
functioning like a battery box, the 50 db setting is probably too high

for

most uses, so I would guess most users leave the gain setting to 29db,

and

do fine setting with the rotary level dial.



Julian wrote:

If the knob increases level or decreases it from the preset gain
switch then you could fine tune each setting. If you wanted less than
29 dB gain, setting the switch to zero and using the level knob might
do it. Probably 29 will be a most usual setting, but If you are
recording bird calls or something really really quiet you'll want the
full 50 dB and then some. You get the basic idea, and all 3 switch
settings can be useful.

Julian




--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

"MS" writes:

"Todd H." wrote in message
...

If you read to the bottom of the page you see the disclosure. 8-)

Just found it. Thank you.

As part of the "affiliate" program are you not allowed to mention products
by competing companies on your site,

Nah, they have no such restrictions.

or do you just happen to have only used SP mics and accessories?

Ding! This is the first I've heard of the Reactive Sounds pre. And
I won't try to talk you out of it. :-) Sounds like it might be
nice. If the clip light there does happen to give you some help in
maximizing your dynamic range with field adjustments, go for it!
Just be aware that you'll still have to do some home experimenting to
find out where the pre's clip level is with respect to the recorder's
clip level.

Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | "4 lines suffice."

"Todd H." wrote in message
...

If you read to the bottom of the page you see the disclosure. 8-)

Just found it. Thank you.

As part of the "affiliate" program are you not allowed to mention products
by competing companies on your site, or do you just happen to have only used
SP mics and accessories?

Thank you for the detailed explanation. I'm not sure I understand it all,
but I will study it more.

When you write: " The reason that adjustable gain is better is
this...." ----

Are you saying that the setup for adjusting the gain on the Reactive PA is
better, as claimed on their web site?

Both have adjustable gain. The difference is that the SP PA has a switch
that selects one of three gain levels (0db, 29db, or 50db), and a rotary
dial that controls level. The Reactive PA only has a rotary dial, but it
controls gain directly, not level. I'm still not sure I understand the
difference between a continuous rotary gain control and a continuous rotary
level control, but I'll read your post again, and see if I can understand
it.

When you write below:

One design Mic in------ Control---- Pre-amp---Line out
Another Mic in------ pre-amp----- control----- line out

are the two designs you refer to the two PAs I described, SP and Reactive?
If so, which is which? You don't write which kind of control, "gain" or
"level". One description puts the control before the pre-amp, and the other
description puts the control after the pre-amp. But in both of these units
the controls are on the pre-amp! Or do you mean that the gain control alters
the signal before (or when) it gets pre-amped, and the level control alters
it after it is pre-amped, or vice versa?

I just notice what you wrote after that description, that in either case the
control is a Level control. Then neither of those cases describes the
Reactive PA, as it only has a gain (continuous rotary) control, not a level
control. I don't know which of the two describes the SP PA.

I think you are saying that the control design of the Reactive PA is better,
although that doesn't necessarily make it better overall. It would be
interesting to see a comparative test of the two units.

"John in Detroit" wrote in message
m...
Oh, you ask what is the difference between "Gain" and "level" controls.

Generally you have one of a few different designs, I can't do ascii
drawing on usenet due to the lack of mono-space fonts guarentee so I do
what call Line graphs instead

One design Mic in------ Control---- Pre-amp---Line out
Another Mic in------ pre-amp----- control----- line out

In either of these cases the GAIN of the pre-amp is fixed, the control
is a LEVEL control, note, that the 2nd one is much better than the first

Yet another design
Mic in------------(pre [control] amp) ----- line out

Note that in this case teh control is PART of the pre-amp, it's a gain
control If I were drawing it Well, try this

Draw a triangle, isoleases Left side vertical, point to the right

This is labeled "Pre-amp"

Now draw a line from the left to a spot about 1/4 the way down from the
top of the vertical (left) side of the amp, it's labeled "MIC IN"

Now draw a line from the point on the right to a label LINE OUT

Now draw a line straight down this line comes down, does a hard right
and ends in an arrow point, Now draw another line, Wavey like
/\/\/\/\/\ this, only vertical, just touching the arrow. a line

It is marked "Gain Control"

What this does is actually vary the GAIN of the pre-amp

The reason that adjustable gain is better is this....

Hi gain amps such as most microphone pre-amps tend to introduce a bit of
noise (Usually a hiss like sound) and if you lower the gain you greatly
lower the additional nosie, But if you lower the OUTPUT with a level
control, all you do is lower everything, sound AND noise

So, if you turn the LEVEL down 1/2, then the noise is reduced 1/2

But if you turn the GAIN down 1/2, then the noise may be reduced to 1/4
or even 1/16th what it was

Ok, that is on paper... In practice... When you start turning down the
gain or level, it don't much matter cause the sound (Desired sound)_ is
loud enough to bury the noise anyway

MS wrote:
"Julian" wrote in message
...

MS wrote:


The SP PA, on the other hand, has a three position switch for gain
(0db,
29db, and 50 db), and a rotary dial for "level". (Could someone please
explain the difference between "gain" and "level"?


Julian wrote:


You immediately answer your question:


No I didn't. (Rest of quote of my previous message, that Julian is
referring
to, appears below this message, and more of his response.) Yes, I said
that
it looks like one would leave the three positions gain switch (on the
SP)
set to one place, and use the rotary continuous level dial for
fine-tuning
it.

However, as I said, the Reactive PA has no gain multi-position switch,
only
a continuous rotary dial. But in this case the continuous rotary dial
controls gain itself, which they (Reactive) asserts is much better, than
having the rotary dial control level, as the SP PA does.

Therefore, my question was not whether a rotary dial is used for fine
tuning, which is rather obvious, but what is actually the difference
between
gain and level, and is there really an advantage (as Reactive asserts)
in
having the rotary dial control gain rather than level?

I also mentioned that it seemed simpler to have the one control of the
Reactive rather than the two of the SP. If the one control was only the
three-position gain switch, with no rotary dial (like the Church Audio
PA),
I'd consider that a distinct disadvantage, with no possibility of
fine-tuning the setting, just three settings to choose from. But with
the
one setting being a continuous rotary dial, controlling gain directly,
that
might be preferable. I really don't know, just asking.

You write: "If the knob (rotary level dial on SP PA) increases level or
decreases it from the preset gain switch..........".

Which does it do---increase or decrease? I have seen no documentation
that
explains it. Anyone know?



MS wrote:

The 0 db setting gives no pre-amp function at all, I guess then
functioning like a battery box, the 50 db setting is probably too high

for

most uses, so I would guess most users leave the gain setting to 29db,

and

do fine setting with the rotary level dial.



Julian wrote:

If the knob increases level or decreases it from the preset gain
switch then you could fine tune each setting. If you wanted less than
29 dB gain, setting the switch to zero and using the level knob might
do it. Probably 29 will be a most usual setting, but If you are
recording bird calls or something really really quiet you'll want the
full 50 dB and then some. You get the basic idea, and all 3 switch
settings can be useful.

Julian




--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

"Julian" wrote in message
...
On Fri, 1 Jul 2005 11:29:35 -0700, "MS" wrote:

Gain and level are the same.

As said, I don't really understand the difference between them, but I think
many would not agree with you that there is no difference between the terms
gain and level.

This one design seems to have a compromise
in that instead of having one big dial, or lots of little switches, it
uses 3 big switches and one small dial.

Which one device has that compromise, 3 big switches and one small dial?
Neither of the devices I mentioned have a setup like that. They both have an
on-off switch. The Reactive PA only has one other control, a continuous
rotary dial that controls gain 0 to 36.5 db. The SP PA has a three position
gain switch to choose between 0db, 29db, or 50db gain, plus a continuous
rotary dial that controls level. I thought that was clear in the original
post, as well as in the web pages about these products. Are you writing
about something different than the two products under discussion here, with
the statement "this one design seems to have a compromise.......".

Theoretically it might sound
better than a unit with one big dial, but one should take a hard long
look at the specs before concluding so. The fact that they even
thought of doing it this way makes me think it might be a better
quality unit than the one with the one big dial.

I don't understand what you are getting at there. What might "theoretically"
sound better than what? The fact that who even thought of doing what which
way tells you what?

Functionally it may be easier to operate, but you'll have to compare
the specs to see if the switches provide any improvement in quality.

I don't understand enough about the specs. Perhaps someone could help with
that.

Which does it do---increase or decrease? I have seen no documentation
that
explains it. Anyone know?

All knobs decrease level. Gain stages usually operate full open. In
your case, Its a question of increase or decrease relative to what?
When you set the switch to 29 dB does that assume the knob is 12
o'clock straight up to get 29 dB, all the way down or all the way up
to get 29 dB? I don't, I don't have a schematic, and I am not a mind
reader! Need more info to answer.

Reading my mind would not help, as I don't know the answer to the question,
I was the one asking it! Yes, that is a good question, concerning the
interplay between the three-position gain switch on the SP PA and the rotary
level dial. If you have the gain set to 29db, does that mean it is 29 with
the level knob set all the way to the left, counter-clockwise, and turning
it clockwise increases the gain. (Well, they don't call that knob gain, but
level. You say they are the same, I'm not sure about that.) How much does
that level dial increase the gain, if turned all the way clockwise? Or, as
you surmise, might it be 29 db when the rotary level dial is set exactly in
the middle, 12 o'clock. You're asking me this question? I don't know, that;s
why I asked it. Unfortunately, I haven't seen documentation on their site
that explains it.

Why do you say "all knobs decrease level"? If you turn the knob to the left
it is decreased, but turning to the right increases it. "Question of
increase or decrease relative to what"? Wasn't that pretty clear? In
relation to the gain setting on the 3 position gain switch (on the SP PA),
of course.

"Todd H." wrote in message
...

Just be aware that you'll still have to do some home experimenting to
find out where the pre's clip level is with respect to the recorder's
clip level.

Any suggestions on how to go about doing that?

MS wrote:

As said, I don't really understand the difference between them, but I think
many would not agree with you that there is no difference between the terms
gain and level.

Gain is what you adjust. Level is what you get.

Continuous gain pots are typically noiser than discrete,
switched resistors.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

MS wrote:
One thing I notice now, in looking at specs. The gain on the Reactive PA is
adjustable (via the rotary dial) from 0 to 36.5 db. Therefore, it does not
go as high as the 50 db setting on the SP PA. I greatly doubt I would ever
need more than 36.5 db gain though. (For someone who would though, the SP
would be a better choice.)

Dynamic mics or ribbons typically require more than 36.5 dB
and some condenser mics have similarly low sensitivities
(Sony ECM-MS907 comes to mind.)

The SP lists a higher signal to noise ratio than the Reactive. I'm not sure
how accurate those specs are though, whether one manufacturer might measure
it different than another, and whether that might make a difference that one
could actually hear. If anyone knows more about this and other specs, please
share your knowledge about it.

You assume they actually measure these things. :-)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

"MS" writes:

"Todd H." wrote in message
...

Just be aware that you'll still have to do some home experimenting to
find out where the pre's clip level is with respect to the recorder's
clip level.

Any suggestions on how to go about doing that?

I don't have a formal methodology. But a radio shack SPL meter, and
taking a peek at your recorders files in a WAV editor and seeing how
close you get to clipping for a given show's SPL is a reasonable
method.

Best Regards,
--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | "4 lines suffice."

I have the SP-PASM-2 which is a pre-amp with built-in stereo mic
(that you can disable by plugging in your own), that works okay,
if you want portability for $199. I can't follow why there's
such a price range for the various SP pre-amps, by the way, but
my standards are not high so I'm uncurious.

The dynamic range is typically so large that you can be pretty
confident if you just record at a low level.

I'm recording into a Creative N200 mp3 player, and just set the level
so that I can barely hear it on the headphones at a volume level of
``20,'' leaving lots of headroom.

The SP-PASM-2 could use a bass rolloff, by the way, as it seems to
bring up almost sub-sonic bass that you normally don't hear, but I
can take it out on playback with the equalizer on the N200.

I have the ``sensitive'' version, and use it for recording bird songs
and night-time distant train whistles. At the highest sensitivity,
switched to 50dB gain, the pre-amp overloads on normal-loud traffic
sounds, but that situation is rather easy to anticipate and avoid.
It's meant to be sensitive, after all.


--
Ron Hardin


On the internet, nobody knows you're a jerk.

NO, what I am saying is that pre-amps generate noise,the lower the gain,
the less noise, WAY LESS.

There is another advantage too.... Generally speaking controls such as
level and gain controls also generage noise when adjusted... Higher
quality controls are not as bad as el-cheapos but you can put a TON of
noise filtering on a gain control for abotru 10 cents wholesale. you
can't use nearly that much filtering on a level control (Since audio
passes through it) No audio passes through a gain control, just DC
control voltage

The next thing... Don't take PAs word for it that Chris
(Soundprofessionals) is using level controls on the lower cost box

Ask Chris. I'm not sure, I've looked at mine and I think it is a gain,
even though it is not labeled at all (In a stereo circuit it is fairly
simple to tell the difference) but mine is an older unit and he have
changed the design since buliding mine.

MS wrote:
Thank you for the detailed explanation. I'm not sure I understand it all,
but I will study it more.

When you write: " The reason that adjustable gain is better is
this...." ----

Are you saying that the setup for adjusting the gain on the Reactive PA is
better, as claimed on their web site?

Both have adjustable gain. The difference is that the SP PA has a switch
that selects one of three gain levels (0db, 29db, or 50db), and a rotary
dial that controls level. The Reactive PA only has a rotary dial, but it
controls gain directly, not level. I'm still not sure I understand the
difference between a continuous rotary gain control and a continuous rotary
level control, but I'll read your post again, and see if I can understand
it.

When you write below:


One design Mic in------ Control---- Pre-amp---Line out
Another Mic in------ pre-amp----- control----- line out


are the two designs you refer to the two PAs I described, SP and Reactive?
If so, which is which? You don't write which kind of control, "gain" or
"level". One description puts the control before the pre-amp, and the other
description puts the control after the pre-amp. But in both of these units
the controls are on the pre-amp! Or do you mean that the gain control alters
the signal before (or when) it gets pre-amped, and the level control alters
it after it is pre-amped, or vice versa?

I just notice what you wrote after that description, that in either case the
control is a Level control. Then neither of those cases describes the
Reactive PA, as it only has a gain (continuous rotary) control, not a level
control. I don't know which of the two describes the SP PA.

I think you are saying that the control design of the Reactive PA is better,
although that doesn't necessarily make it better overall. It would be
interesting to see a comparative test of the two units.

"John in Detroit" wrote in message
m...

Oh, you ask what is the difference between "Gain" and "level" controls.

Generally you have one of a few different designs, I can't do ascii
drawing on usenet due to the lack of mono-space fonts guarentee so I do
what call Line graphs instead

One design Mic in------ Control---- Pre-amp---Line out
Another Mic in------ pre-amp----- control----- line out

In either of these cases the GAIN of the pre-amp is fixed, the control
is a LEVEL control, note, that the 2nd one is much better than the first

Yet another design
Mic in------------(pre [control] amp) ----- line out

Note that in this case teh control is PART of the pre-amp, it's a gain
control If I were drawing it Well, try this

Draw a triangle, isoleases Left side vertical, point to the right

This is labeled "Pre-amp"

Now draw a line from the left to a spot about 1/4 the way down from the
top of the vertical (left) side of the amp, it's labeled "MIC IN"

Now draw a line from the point on the right to a label LINE OUT

Now draw a line straight down this line comes down, does a hard right
and ends in an arrow point, Now draw another line, Wavey like
/\/\/\/\/\ this, only vertical, just touching the arrow. a line

It is marked "Gain Control"

What this does is actually vary the GAIN of the pre-amp

The reason that adjustable gain is better is this....

Hi gain amps such as most microphone pre-amps tend to introduce a bit of
noise (Usually a hiss like sound) and if you lower the gain you greatly
lower the additional nosie, But if you lower the OUTPUT with a level
control, all you do is lower everything, sound AND noise

So, if you turn the LEVEL down 1/2, then the noise is reduced 1/2

But if you turn the GAIN down 1/2, then the noise may be reduced to 1/4
or even 1/16th what it was

Ok, that is on paper... In practice... When you start turning down the
gain or level, it don't much matter cause the sound (Desired sound)_ is
loud enough to bury the noise anyway

MS wrote:

"Julian" wrote in message
...

MS wrote:



The SP PA, on the other hand, has a three position switch for gain

(0db,

29db, and 50 db), and a rotary dial for "level". (Could someone please
explain the difference between "gain" and "level"?


Julian wrote:



You immediately answer your question:


No I didn't. (Rest of quote of my previous message, that Julian is

referring

to, appears below this message, and more of his response.) Yes, I said

that

it looks like one would leave the three positions gain switch (on the

SP)

set to one place, and use the rotary continuous level dial for

fine-tuning

it.

However, as I said, the Reactive PA has no gain multi-position switch,

only

a continuous rotary dial. But in this case the continuous rotary dial
controls gain itself, which they (Reactive) asserts is much better, than
having the rotary dial control level, as the SP PA does.

Therefore, my question was not whether a rotary dial is used for fine
tuning, which is rather obvious, but what is actually the difference

between

gain and level, and is there really an advantage (as Reactive asserts)

in

having the rotary dial control gain rather than level?

I also mentioned that it seemed simpler to have the one control of the
Reactive rather than the two of the SP. If the one control was only the
three-position gain switch, with no rotary dial (like the Church Audio

PA),

I'd consider that a distinct disadvantage, with no possibility of
fine-tuning the setting, just three settings to choose from. But with

the

one setting being a continuous rotary dial, controlling gain directly,

that

might be preferable. I really don't know, just asking.

You write: "If the knob (rotary level dial on SP PA) increases level or
decreases it from the preset gain switch..........".

Which does it do---increase or decrease? I have seen no documentation

that

explains it. Anyone know?



MS wrote:


The 0 db setting gives no pre-amp function at all, I guess then
functioning like a battery box, the 50 db setting is probably too high

for


most uses, so I would guess most users leave the gain setting to 29db,

and


do fine setting with the rotary level dial.



Julian wrote:


If the knob increases level or decreases it from the preset gain
switch then you could fine tune each setting. If you wanted less than
29 dB gain, setting the switch to zero and using the level knob might
do it. Probably 29 will be a most usual setting, but If you are
recording bird calls or something really really quiet you'll want the
full 50 dB and then some. You get the basic idea, and all 3 switch
settings can be useful.

Julian



--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes




--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

Bob Cain wrote:


You assume they actually measure these things. :-)

(Signal to noise ratios)

I don't know for sure but suspect Chris does indeed do those measurements

In the field of Radio gear.... I know the factory specs for signal to
noise are generally what one would call conservative, I belong to an
origination that does it's own "Field testing" of the radios, including
signal to noise, and usually the test unit (which is purchased at random
off a dealer's shelf, similar to what Consumer Reports claims it does)
usually outperforms the specs (Very slightly)

Though this origination does not do audio gear (other than
communications mics and processors) I'm sure that such a independent
test lab does exist for audio gear so if a company were to make WAC's
(You know what the W(ild) is, and I'm sure you can guess the "A", the C
is "Claim") for their performance specs it would be common knowledge all
over the net 10 minutes later.

I have only heard one dissatisfied costumer report with
SoundProfessinals and have heard many, many happy customer reports, my
own included, (And I won't name the companies who got bad reviews)


That said... Every company from time to time makes a blunder. Can't be
helped. Chris has shown a willingness to make it right however that is
unmatched far as I can tell

My original battery box (Which got lost was cross wired, right became
left passing through the box. not really a problem as I just wore the
mics backwards when using it. But Chris actually CALLED to offer a
replacement when I asked (here) for his phone number back before web
sites were as good as they are today.



--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

John in Detroit wrote:

NO, what I am saying is that pre-amps generate noise,the lower the gain,
the less noise, WAY LESS.

If it's like radio, the noise figure of the first amplifier gives mostly
the noise figure of the whole system. So it's not a matter whether pre-amps
generate noise, but whether they generate more or less than the amplifier
that follows them, that gives the noise performance of the system.

ie. the signal has to be amplified _somewhere_, and you want it done _first_
in the quietest amplifier.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

John in Detroit writes:

That said... Every company from time to time makes a blunder. Can't
be helped. Chris has shown a willingness to make it right however
that is unmatched far as I can tell.


I can vouch for this. My criticism of the design of the original
preamplified mic iteration was taken to heart, and the design improved
and fixed. Now I recommend it without reservation.

Best Regards,

--
/"\ ASCII Ribbon Campaign | Todd H
\ / | http://www.toddh.net/
X Promoting good netiquette | http://triplethreatband.com/
/ \ http://www.toddh.net/netiquette/ | "4 lines suffice."

I will agree with you with the proviso that I now more about radio than
audio in this case.

All I'm saying is that if you lower the gain, you really lower the noise

But if you lower the level, then the noise remains the same, relative to
the signal


And for the person who said gain and level are the same thing... NOT IF
THEY ARE PROPERLY LABELED I have a television in front of me which does
not have a volume (level) control on it, it has a GAIN control, No audio
goes through the GAIN control, it is simply a DC voltage divider nothing
more. Thus filtering any noise generated by the control is very easy

By the way, how to tell... A GAIN control has 3 connections to it,
Usually B+ (Battery plus in this case) Ground and wiper (Variable or
output in this case)

A Stereo LEVEL control has six, 2 ground, two "Output from whatever is
in front of it" and two "Wiper" or "Output to whatever is behind it"
Note, that this simple type can mess up impedance matching too, a Gain
control does not do that.

Older tube type hardware normally used volume controls cause B+ was on
the order of 100 volts or more, usually more. Modern transistor stuff
with voltages of 10 or less often use Gain cause, believe it or not, not
only is it better but it's cheaper. However a 10 buck transistor radio
may well use either.

But if properly labeled GAIN affects the parameters of an amplifier stage
LEVEL is between two stages, or between either input or output and the
pre-amp. They are very clearly not the same

Some folks mis-label them however

(Apologies to the person this is in reply to... I know the rant is not
to you)

Ron Hardin wrote:
John in Detroit wrote:

NO, what I am saying is that pre-amps generate noise,the lower the gain,
the less noise, WAY LESS.


If it's like radio, the noise figure of the first amplifier gives mostly
the noise figure of the whole system. So it's not a matter whether pre-amps
generate noise, but whether they generate more or less than the amplifier
that follows them, that gives the noise performance of the system.

ie. the signal has to be amplified _somewhere_, and you want it done _first_
in the quietest amplifier.

--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

I should tell you that I'm one of the folks who asked Chris to come out
with a b-box/pre-amp combo... Don't know if I was first, but clearly he
came out with one... I do like the way that man runs stuff

Todd H. wrote:
John in Detroit writes:


That said... Every company from time to time makes a blunder. Can't
be helped. Chris has shown a willingness to make it right however
that is unmatched far as I can tell.



I can vouch for this. My criticism of the design of the original
preamplified mic iteration was taken to heart, and the design improved
and fixed. Now I recommend it without reservation.

Best Regards,


--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

"John in Detroit" wrote in message
...
NO, what I am saying is that pre-amps generate noise,the lower the gain,
the less noise, WAY LESS.

I am not sure what you are saying NO too.

If your NO is that you were not implying that the Reactive control design is
better, once more your statement above, and in the following paragraph
implies that it does. With the SP PA one might set the gain higher than
necessary (with only three levels), then attenuate it with the level
control. With the Reactive one wouldn't have to set the gain any higher than
necessary.


There is another advantage too.... Generally speaking controls such as
level and gain controls also generage noise when adjusted... Higher
quality controls are not as bad as el-cheapos but you can put a TON of
noise filtering on a gain control for abotru 10 cents wholesale. you
can't use nearly that much filtering on a level control (Since audio
passes through it) No audio passes through a gain control, just DC
control voltage

The next thing... Don't take PAs word for it that Chris
(Soundprofessionals) is using level controls on the lower cost box

PA's word for it? (A talking pre-amp? ;-) ) I think you mean SP. Since the
rotary gain control is better than rotary level (it seems like you implied
that), why would he have a gain control and call it level. Besides, if the
rotary dial controlled gain, what need is there for the three position
switch? Which "lower cost box" are you referring to? Both of the products
under discussion here cost about the same ($179).


MS wrote:
Thank you for the detailed explanation. I'm not sure I understand it
all,
but I will study it more.

When you write: " The reason that adjustable gain is better is
this...." ----

Are you saying that the setup for adjusting the gain on the Reactive PA
is
better, as claimed on their web site?

Both have adjustable gain. The difference is that the SP PA has a switch
that selects one of three gain levels (0db, 29db, or 50db), and a rotary
dial that controls level. The Reactive PA only has a rotary dial, but it
controls gain directly, not level. I'm still not sure I understand the
difference between a continuous rotary gain control and a continuous
rotary
level control, but I'll read your post again, and see if I can
understand
it.

When you write below:


One design Mic in------ Control---- Pre-amp---Line out
Another Mic in------ pre-amp----- control----- line out


are the two designs you refer to the two PAs I described, SP and
Reactive?
If so, which is which? You don't write which kind of control, "gain" or
"level". One description puts the control before the pre-amp, and the
other
description puts the control after the pre-amp. But in both of these
units
the controls are on the pre-amp! Or do you mean that the gain control
alters
the signal before (or when) it gets pre-amped, and the level control
alters
it after it is pre-amped, or vice versa?

I just notice what you wrote after that description, that in either case
the
control is a Level control. Then neither of those cases describes the
Reactive PA, as it only has a gain (continuous rotary) control, not a
level
control. I don't know which of the two describes the SP PA.

I think you are saying that the control design of the Reactive PA is
better,
although that doesn't necessarily make it better overall. It would be
interesting to see a comparative test of the two units.

"John in Detroit" wrote in message
m...

Oh, you ask what is the difference between "Gain" and "level" controls.

Generally you have one of a few different designs, I can't do ascii
drawing on usenet due to the lack of mono-space fonts guarentee so I do
what call Line graphs instead

One design Mic in------ Control---- Pre-amp---Line out
Another Mic in------ pre-amp----- control----- line out

In either of these cases the GAIN of the pre-amp is fixed, the control
is a LEVEL control, note, that the 2nd one is much better than the first

Yet another design
Mic in------------(pre [control] amp) ----- line out

Note that in this case teh control is PART of the pre-amp, it's a gain
control If I were drawing it Well, try this

Draw a triangle, isoleases Left side vertical, point to the right

This is labeled "Pre-amp"

Now draw a line from the left to a spot about 1/4 the way down from the
top of the vertical (left) side of the amp, it's labeled "MIC IN"

Now draw a line from the point on the right to a label LINE OUT

Now draw a line straight down this line comes down, does a hard right
and ends in an arrow point, Now draw another line, Wavey like
/\/\/\/\/\ this, only vertical, just touching the arrow. a line

It is marked "Gain Control"

What this does is actually vary the GAIN of the pre-amp

The reason that adjustable gain is better is this....

Hi gain amps such as most microphone pre-amps tend to introduce a bit of
noise (Usually a hiss like sound) and if you lower the gain you greatly
lower the additional nosie, But if you lower the OUTPUT with a level
control, all you do is lower everything, sound AND noise

So, if you turn the LEVEL down 1/2, then the noise is reduced 1/2

But if you turn the GAIN down 1/2, then the noise may be reduced to 1/4
or even 1/16th what it was

Ok, that is on paper... In practice... When you start turning down the
gain or level, it don't much matter cause the sound (Desired sound)_ is
loud enough to bury the noise anyway

MS wrote:

"Julian" wrote in message
...

MS wrote:



The SP PA, on the other hand, has a three position switch for gain

(0db,

29db, and 50 db), and a rotary dial for "level". (Could someone
please
explain the difference between "gain" and "level"?


Julian wrote:



You immediately answer your question:


No I didn't. (Rest of quote of my previous message, that Julian is

referring

to, appears below this message, and more of his response.) Yes, I said

that

it looks like one would leave the three positions gain switch (on the

SP)

set to one place, and use the rotary continuous level dial for

fine-tuning

it.

However, as I said, the Reactive PA has no gain multi-position switch,

only

a continuous rotary dial. But in this case the continuous rotary dial
controls gain itself, which they (Reactive) asserts is much better,
than
having the rotary dial control level, as the SP PA does.

Therefore, my question was not whether a rotary dial is used for fine
tuning, which is rather obvious, but what is actually the difference

between

gain and level, and is there really an advantage (as Reactive asserts)

in

having the rotary dial control gain rather than level?

I also mentioned that it seemed simpler to have the one control of the
Reactive rather than the two of the SP. If the one control was only the
three-position gain switch, with no rotary dial (like the Church Audio

PA),

I'd consider that a distinct disadvantage, with no possibility of
fine-tuning the setting, just three settings to choose from. But with

the

one setting being a continuous rotary dial, controlling gain directly,

that

might be preferable. I really don't know, just asking.

You write: "If the knob (rotary level dial on SP PA) increases level or
decreases it from the preset gain switch..........".

Which does it do---increase or decrease? I have seen no documentation

that

explains it. Anyone know?



MS wrote:


The 0 db setting gives no pre-amp function at all, I guess then
functioning like a battery box, the 50 db setting is probably too
high

for


most uses, so I would guess most users leave the gain setting to
29db,

and


do fine setting with the rotary level dial.



Julian wrote:


If the knob increases level or decreases it from the preset gain
switch then you could fine tune each setting. If you wanted less than
29 dB gain, setting the switch to zero and using the level knob might
do it. Probably 29 will be a most usual setting, but If you are
recording bird calls or something really really quiet you'll want the
full 50 dB and then some. You get the basic idea, and all 3 switch
settings can be useful.

Julian



--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes




--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

MS wrote:
"John in Detroit" wrote in message
...

NO, what I am saying is that pre-amps generate noise,the lower the gain,
the less noise, WAY LESS.

You ask "are you saying Reactive Controls system is better" and I said
NO, I'm not, since I do not have a Reactive Controle unit in hand I
can't say that (NOTE: I'm also not saying it's not better, I simply do
not know) The unit I have is the one from Sound Professionals and it's
the one with just two controls, ON/OFF and roatary


The next thing... Don't take PAs word for it that Chris
(Soundprofessionals) is using level controls on the lower cost box


PA's word for it? (A talking pre-amp? ;-) ) I think you mean SP. Since the
rotary gain control is better than rotary level (it seems like you implied
that), why would he have a gain control and call it level. Besides, if the
rotary dial controlled gain, what need is there for the three position
switch? Which "lower cost box" are you referring to? Both of the products
under discussion here cost about the same ($179).

Sorry... Lost my place in the post, by "PA" I meant Reactive Controls
(RC) My mistake

Finally by "Lower cost box" I mean the one Chris sells without the 3
position gain switch, just the roatary control (As noted above)


I have opened it and looked at it and I think it's a gain control not a
stereo level control.... However in truth I'm not sure

--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

"John in Detroit" wrote in message
. ..


MS wrote:
"John in Detroit" wrote in message
...

NO, what I am saying is that pre-amps generate noise,the lower the gain,
the less noise, WAY LESS.

You ask "are you saying Reactive Controls system is better" and I said
NO, I'm not, since I do not have a Reactive Controle unit in hand I
can't say that (NOTE: I'm also not saying it's not better, I simply do
not know) The unit I have is the one from Sound Professionals and it's
the one with just two controls, ON/OFF and roatary

OK. Sorry for the misunderstanding. I didn't imply that you said that the
Reactive unit is better, since you haven't tried one. (You would have
mentioned it if you have.) What I said was, sorry if it wasn't clear, that
it sounded to me like you were saying that the control setup on the Reactive
unit sounded like a better setup, where the rotary dial controls gain,
whereas it controls level on the SP model. Of course that doesn't make the
RS (Reactive Sounds) PA better as a whole, and you have never used one. Only
that it sounded like you were saying that the control setup, as described in
the URLs I gave for the manufacturer's web oages of both, sounded like a
better control setup. Is that fair to say?

Yes, I forgot that SP also makes a lower cost one without the three position
gain switch. It is described that the gain is not adjustable, fixed at 40db.
I assumed this would not be a good one to get, with no adjustability. I was
not aware that it had the rotary dial, which probably controls level like
the other SP. With that rotary dial, it's probably quite usable. I was
looking at the more expensive "gain-selectable" SP PA, which has the three
position gain switch (0, 29, and 50 db), and the rotary level dial. Since
for most uses one would probably set the gain to the 29db switch and leave
it there, doing finer control with the rotary level dial, for most people
(other than those who need the 0 and 50db gain settings), the lower cost one
without gain control might be fine. The RS unit is the same price as the
$180 "gain-selectable" SP PA. Like the SP PA you have, it only has two
controls, an on-off switch and a rotary dial. But in this case, according to
the manufacturer, the rotary dial controls gain, not level. According to
your description, it sounds like it is better for the rotary dial to control
gain rather than level, as the RS web site also says. Of course, that does
not mean that it is better overall. The specs for the SP unit report a
higher S/N ratio, for example, than the RS one, for example, which favors
the SP. (I don't know how accurate those specs are though.) SP also has the
advantage (for stealth recording) of being smaller. RS has the advantage of
the clipping light, which could be useful when recording without a level
meter, such as with my Iriver H120 mp3 player/recorder.

It would be interesting to read a comparative review of the two units, from
someone who tried and tested both, and could compare in all aspects.
Unfortunately, such a review probably doesn't exist. (If someone knows of
such a review, please post a link here.)

"MS" writes:
It would be interesting to read a comparative review of the two
units, from someone who tried and tested both, and could compare in
all aspects. Unfortunately, such a review probably doesn't
exist. (If someone knows of such a review, please post a link here.)

I would be happy to perform such a review if provided a Reactive
unit. Nah, crap I probably wouldn't because my SP unit works great and
it wouldn't be worth my time.

Until then, my oft used advice in threads that get to this level of
detail with no clear resolution in sight is: JBS*










* Just buy something! (I strongly suspect you'll be happy with the SP
unit though. )

Best Regards,
--
Todd's Creative Nomad Jukebox Recording Page
http://toddh.net/music/njb/

John in Detroit writes:

MS wrote:
"John in Detroit" wrote in message
...

NO, what I am saying is that pre-amps generate noise,the lower the gain,
the less noise, WAY LESS.

You ask "are you saying Reactive Controls system is better" and I said
NO, I'm not, since I do not have a Reactive Controle unit in hand I
can't say that (NOTE: I'm also not saying it's not better, I simply do
not know) The unit I have is the one from Sound Professionals and it's
the one with just two controls, ON/OFF and roatary


The next thing... Don't take PAs word for it that Chris
(Soundprofessionals) is using level controls on the lower cost box


PA's word for it? (A talking pre-amp? ;-) ) I think you mean SP. Since the
rotary gain control is better than rotary level (it seems like you implied
that), why would he have a gain control and call it level. Besides, if the
rotary dial controlled gain, what need is there for the three position
switch? Which "lower cost box" are you referring to? Both of the products
under discussion here cost about the same ($179).

Sorry... Lost my place in the post, by "PA" I meant Reactive Controls
(RC) My mistake

Finally by "Lower cost box" I mean the one Chris sells without the 3
position gain switch, just the roatary control (As noted above)


I have opened it and looked at it and I think it's a gain control not a
stereo level control.... However in truth I'm not sure

--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

Dear John,

Hey, if you've taken those boxes apart, can you tell me what chips are inside?

I built the following circuit:
http://www.geocities.com/ferocious_1...icpreamp2.html

The only difference was that I put a gain control in the feedback loop. So,
from OUT to IN- I put a 4.7KR resisitor in series with a 50KR (linear)
pot. From IN- to ground I put a 4.7KR resistor. I replaced the output pot with
a fixed 10KR load resistor. The voltage gain *should* now be approx. 2 to
12.6, or about 6 to 22 in dB.

I'm looking for the same thing you a a moderate boost to record from
reasonably "hot" condenser mics, and variable gain to prevent overloading.

I've used NE5532A and OPA2134 chips so far. They both sound OK, though
I'm looking for the best chip, both in terms of sound and lowest battery
power.

Richard

Ok, looks like we are on the same page now

The only thing I can add is this... I'm very happy with my B-Box pre-amp

Depending on the recording I use different arraingments.

Sony-single point stereo (Direct to the MD) SoundProfessionals Low-cost
binaurals (normally to line in via the b-box/pre-amp and a pair of
professional grade dynamics via a Tapco mixer/pre-amp (six channel) to
the line in on whatever device is being used to record (Normally HI-MD
now, in the past it varied more)

One recording was a "live" recording in a room not favorable for that
kind of thing.... I burned it to CD and mailed it off to the performer
(He requested) he was impressed with the job done... I did a decent job
of mic placement and gain setting on the tapco.

I continue to be impressed by what a pocket size recorder can do

MS wrote:
"John in Detroit" wrote in message
. ..


MS wrote:

"John in Detroit" wrote in message
.. .


NO, what I am saying is that pre-amps generate noise,the lower the gain,
the less noise, WAY LESS.

You ask "are you saying Reactive Controls system is better" and I said
NO, I'm not, since I do not have a Reactive Controle unit in hand I
can't say that (NOTE: I'm also not saying it's not better, I simply do
not know) The unit I have is the one from Sound Professionals and it's
the one with just two controls, ON/OFF and roatary


OK. Sorry for the misunderstanding. I didn't imply that you said that the
Reactive unit is better, since you haven't tried one. (You would have
mentioned it if you have.) What I said was, sorry if it wasn't clear, that
it sounded to me like you were saying that the control setup on the Reactive
unit sounded like a better setup, where the rotary dial controls gain,
whereas it controls level on the SP model. Of course that doesn't make the
RS (Reactive Sounds) PA better as a whole, and you have never used one. Only
that it sounded like you were saying that the control setup, as described in
the URLs I gave for the manufacturer's web oages of both, sounded like a
better control setup. Is that fair to say?

Yes, I forgot that SP also makes a lower cost one without the three position
gain switch. It is described that the gain is not adjustable, fixed at 40db.
I assumed this would not be a good one to get, with no adjustability. I was
not aware that it had the rotary dial, which probably controls level like
the other SP. With that rotary dial, it's probably quite usable. I was
looking at the more expensive "gain-selectable" SP PA, which has the three
position gain switch (0, 29, and 50 db), and the rotary level dial. Since
for most uses one would probably set the gain to the 29db switch and leave
it there, doing finer control with the rotary level dial, for most people
(other than those who need the 0 and 50db gain settings), the lower cost one
without gain control might be fine. The RS unit is the same price as the
$180 "gain-selectable" SP PA. Like the SP PA you have, it only has two
controls, an on-off switch and a rotary dial. But in this case, according to
the manufacturer, the rotary dial controls gain, not level. According to
your description, it sounds like it is better for the rotary dial to control
gain rather than level, as the RS web site also says. Of course, that does
not mean that it is better overall. The specs for the SP unit report a
higher S/N ratio, for example, than the RS one, for example, which favors
the SP. (I don't know how accurate those specs are though.) SP also has the
advantage (for stealth recording) of being smaller. RS has the advantage of
the clipping light, which could be useful when recording without a level
meter, such as with my Iriver H120 mp3 player/recorder.

It would be interesting to read a comparative review of the two units, from
someone who tried and tested both, and could compare in all aspects.
Unfortunately, such a review probably doesn't exist. (If someone knows of
such a review, please post a link here.)




--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

"John in Detroit" wrote in message
m...

Sony-single point stereo (Direct to the MD)

OT, but I'm curious--since you have the pre-amp, why do you run the Sony mic
(907?) direct to the MD recorder, and not through the pre-amp?

Depends on the recording situtation... I have 3 working portable
recorders, I have 4 Mini-Disc portables, 3 work well, the R-2 is a bit
iffy, I have 3 sets of stereo microphones plus the interview stealth
mic (mono) I have two pre-amps

One preamp works best with the binaurals since they are P-iN-P

One premap works only with the "professional" mics since they and it are
XLR

And the Sony Single point has it's own bulit in battery and thus needs
on external pre-amp if I am willing to use the recorder in ALC mode

Since I, personally, can not be in 3 rooms at one time.... I use the
Sony mic, on a stand, with one recorder, The "professionals" either
hanging from a support or on a stand with their pre-amp and automatic
limiter, and the Low Cost Binaurals, hang on me (Well my glasses) with
the pre-amp and remaining recorder.


MS wrote:
"John in Detroit" wrote in message
m...


Sony-single point stereo (Direct to the MD)


OT, but I'm curious--since you have the pre-amp, why do you run the Sony mic
(907?) direct to the MD recorder, and not through the pre-amp?



--
John F Davis, in Delightful Detroit. WA8YXM(at)arrl(dot)net
"Nothing adds excitement like something that is none of your business"
Diabetic? http://community.compuserve.com/diabetes

Hi all:

Just thought I would clarify. Our preamps *all* use a level control on
the output.....after the amplification stage.

However, the SP-PREAMP with the 3 gain settings has 3 gain choices. The
reason for this is, whenever possible, you don't want to apply any more
gain than is necessary to a signal. It's better to apply as little gain
as possible to a signal (which also means less noise) then to apply too
much and attenuate it down at the end.

With the 3 gain settings, you only apply as much gain as you need, then
fine tune the final level with the output control.

In the end, you might want to try both and then just keep the one you
like better :-)

Chris Carfagno
The SOUND Professionals, Inc.
800-213-3021
www.soundprofessionals.com

Todd H. wrote:
"MS" writes:
It would be interesting to read a comparative review of the two
units, from someone who tried and tested both, and could compare in
all aspects. Unfortunately, such a review probably doesn't
exist. (If someone knows of such a review, please post a link here.)

I would be happy to perform such a review if provided a Reactive
unit. Nah, crap I probably wouldn't because my SP unit works great and
it wouldn't be worth my time.

Until then, my oft used advice in threads that get to this level of
detail with no clear resolution in sight is: JBS*










* Just buy something! (I strongly suspect you'll be happy with the SP
unit though. )

Best Regards,
--
Todd's Creative Nomad Jukebox Recording Page
http://toddh.net/music/njb/