[dwk]

No, I think he meant they *are* in the signal path. From the reference board schematics, gain on the amps is set via a pair of feedback resistors, similar to an op-amp. It's a reasonable assumption that the Pot is used to replace either 1 or both of these fixed resistors with a variable resistor to alter the gain.
 So, they are most likely in the feedback loop, which is definitely  'in the signal path'

[jtwrace]

No, I think he meant they *are* in the signal path. From the reference board schematics, gain on the amps is set via a pair of feedback resistors, similar to an op-amp. It's a reasonable assumption that the Pot is used to replace either 1 or both of these fixed resistors with a variable resistor to alter the gain.
 So, they are most likely in the feedback loop, which is definitely  'in the signal path'

You are correct.  If they are not soldered in, the amp is dead silent.  In a bad way.   

[Barry_NJ]

No, I think he meant they *are* in the signal path. From the reference board schematics, gain on the amps is set via a pair of feedback resistors, similar to an op-amp. It's a reasonable assumption that the Pot is used to replace either 1 or both of these fixed resistors with a variable resistor to alter the gain.
 So, they are most likely in the feedback loop, which is definitely  'in the signal path'

Then couldn't a jumper of some type be used to replace them?

[avionic]

  Gain adjustments are for matching the pre amp to the amp.  Set it and forget it. Almost all car audio amplifiers have a gain adjustment due to the different output voltage of diff. head units.
   My suggestion would be to read up on gain adj.(tons of info out there) and set the gain to match your pre. It really is a very nice feature to have. Also nice if you have more than one amp with gain adj. you could match the levels of the amps.
   For me it is nice because I have hearing loss in my left ear( to much loud car audio) so I can adjust the left side up a little and get everything centered. My 2&1/2 cents.

[Barry_NJ]

My pre-amp has volume and balance controls, why would I want a second set in my amp?

[srb]

My pre-amp has volume and balance controls, why would I want a second set in my amp?

By adjusting the gain of the amplifier, it can better match the output of the preamp so that the preamp's volume control can have a greater useable range.
 
A high gain amplifier used with a high output preamplifier can result in a narrow volume control range that can make fine volume adjustments difficult, for example if the combination results in maximum volume reached at a volume control position of only 9:00 o'clock.
 
Steve

[wushuliu]

My pre-amp has volume and balance controls, why would I want a second set in my amp?

Then just get a CDA amp and have Tom set the gain at whatever you prefer.

[srb]

Then just get a CDA amp and have Tom set the gain at whatever you prefer.

But i thought the difference between the CDA and SDS amplifiers was more than just balanced inputs, gain controls, better cooling and LED headers.  Posters in this thread have said that the SDS sounds better, and if I am not mistaken, you were among them?
 
Steve

[wushuliu]

But i thought the difference between the CDA and SDS amplifiers was more than just balanced inputs, gain controls, better cooling and LED headers.  Posters in this thread have said that the SDS sounds better, and if I am not mistaken, you were among them?
 
Steve

Don't think so. Haven't heard one! As for whether it's better regardless of those new features is a good question. Would be interesting to compare a CDA and SDS w/ equivalent input impedance and gain, etc (are the CDA still 7k input impedance?). - for those who don't need balanced inputs anayway...

[srb]

Sorry, I was mistaken.  It was one of Steve K's posts I was thinking of:
 

I and my friends clearly hear a difference in the imaging of the Super D amp. Tom sent me one to verify this because he heard the difference and wanted some outside verifcation.

And from the Class D Audio website:
 
"Our Super D Series amps provide more life-like imaging and sound stage, along with the beautiful smooth tube-like sound we're known for. These amps are powerful, clean, quiet , and transparent"
 
It's probably a subtle difference, but with the additional features including larger heatsinking, I will probably go with the SDS version.  I suppose one could always solder resistors to the gain control headers, once that perfect value for your particular system was determined by use of the gain controls.
 
Steve

 
 
 

[Feanor]

By adjusting the gain of the amplifier, it can better match the output of the preamp so that the preamp's volume control can have a greater useable range.
 
A high gain amplifier used with a high output preamplifier can result in a narrow volume control range that can make fine volume adjustments difficult, for example if the combination results in maximum volume reached at a volume control position of only 9:00 o'clock.
 
Steve

I realize the validity of this this despite my original question on about the pots -- but wouldn't it be nice if CDA actually provide a sensitivity specification for the product?  Forgive me if I say the specifications in general are pretty scant.

[roymail]

Direct your questions to Tom, he's very responsive and helpful. 

[Nick77]

        It's probably a subtle difference,                                       

Its a little more than subtle, but system dependent. If you have a revealing system the difference is much better control.

[jtwrace]

Tom will make the gain whatever you choose.  I'm confused about all the fuss over gain pots (which are a good think IMO).

As for the Super D vs IR Board sonically this will be dependent on YOUR ears and YOUR system.  There is no doubt (to me) that the adustable gain pots are a nice feature for initial system setup.  Once they're set, they're set as long as you don't change components...the good thing is that you can change the gain if you so choose. 

Then again, maybe I'm crazy!  OK.  I am.   

[Feanor]

Direct your questions to Tom, he's very responsive and helpful. 

Tom is indeed very responsive and I thank him for it.  On the other hand he only said I needed to use the gain pots and that I "will like them", (see above), which isn't has helpful as if he'd offer explanation and/or alternative suggestions.

[Barry_NJ]

Tom will make the gain whatever you choose.  I'm confused about all the fuss over gain pots (which are a good think IMO).

As for the Super D vs IR Board sonically this will be dependent on YOUR ears and YOUR system.  There is no doubt (to me) that the adustable gain pots are a nice feature for initial system setup.  Once they're set, they're set as long as you don't change components...the good thing is that you can change the gain if you so choose. 

Then again, maybe I'm crazy!  OK.  I am.   

I'd like to keep the signal path as simple as possible. Also since there is a separate trim pot for each channel, how can you be sure they are set equally? If the gain really must be set, I'd prefer a choice of a few matched resistors that could be inserted/selected via a jumper.

My pre-amp has an adjustment range from -96 to +31.5 dB in half dB increments, so it should be no problem for me to find a usable setting for the volume without having an additional set of adjustments inside the amplifier.

[Nick77]

You guys are missing the point, the benefit of the Super is not having adjustable gain but the the rare Ingenus input receiver Tom is fitting the board with. Its super low noise gives the amp control that shines over the regular series even while using rca's.

I'd like to keep the signal path as simple as possible. Also since there is a separate trim pot for each channel, how can you be sure they are set equally? If the gain really must be set, I'd prefer a choice of a few matched resistors that could be inserted/selected via a jumper.

My pre-amp has an adjustment range from -96 to +31.5 dB in half dB increments, so it should be no problem for me to find a usable setting for the volume without having an additional set of adjustments inside the amplifier.

[jtwrace]

You guys are missing the point, the benefit of the Super is not having adjustable gain but the the rare Ingenus input receiver Tom is fitting the board with. Its super low noise gives the amp control that shines over the regular series even while using rca's.

I don't think I'm missing the point...I've been futzing with the Super D for awhile now. 

[Nick77]

I don't think I'm missing the point...I've been futzing with the Super D for awhile now.

Jason like you said it is system dependent. But my experience was equal to Steve K and Tom's thoughts about the Super having much better control. Adjustable gain is certainly a nice feature also.

[jtwrace]

Jason like you said it is system dependent. But my experience was equal to Steve K and Tom's thoughts about the Super having much better control.

OK.  and?