Where is the best place to add a volume control on this TDA3122 audio amp?

[millionreason]

I'd like to add a volume control to the following circuit (a 2x15W Class-D Stereo Power Amp Kit). The schematic below is an image clipped from a TDA3122 PDF (http://www.kynix.com/uploadfiles/pdf65976/TPA3122D2N.pdf) I found describing it.
This'll be being driven almost exclusively from my PC soundcard in case that changes anything. (I'd rather not exclusively use software volume control; I prefer the preciseness of an analog potentiometer :P)
Using a rheostat circuit on the audio input vaguely comes to mind, and that might turn out to be all I need, but I thought I'd ask anyway since I'm not certain (I know precisely zero about electronics).
I'm not familiar with the TDA3122 but I was thinking maybe fiddling with the
GAINA0/GAINA1 lines might produce the effect I'm looking for...? What might I alter here?

76992

[grumpy]

diyaudio.com has some threads on this amp... at least one with volume pot questions/responses.

Frankly, I'd set the fixed gain level, using the pins you've pointed out,
as low as I could (both gain pins shorted to ground) if that provides
enough volume with the computer output maxed... and just use the computer
volume control.

That said, you -could- use a pot wired as a rheostat (http://www.resistorguide.com/rheostat/)
to replace the input 10K and another in series (between the input jack and the DC blocking capacitor)
otherwise, when you turn the volume down you'll short the computer output to ground.

diyaudio is a much better place for such questions though... perhaps some better ideas.

Have fun.

[JeffW]

They quit making them, but Emotiva made a neat desktop volume control knob, the Control Freak. I use one on a computer system I run with amps that have no attenuation controls.

Not mine, just for reference

http://img.canuckaudiomart.com/uploads/large/834832-emotive-control-freak-ubal.jpg

[grumpy]

https://www.parts-express.com/alps-10kax2-10k-ohm-audio-taper-stereo-potentiometer-6mm-shaft--023-204

... or a ganged-pair of 10kohm audio-taper potentiometers (each replacing the 10K resistor to ground on the input)
with the pot's wiper going to the dc blocking cap.

I'm presuming that's what's in the Emotiva passive volume control. Other folks make those as well.

[toddalin]

I would use a stereo 100K audio taper (log) with a pair of 1K resistors to keep the signal from going to ground. Look How I set up the audio pots in this schematic (upper left).

http://www.audioheritage.org/photopost/data//500/medium/ScreenHunter_125_Dec_28_16_50.jpg

[millionreason]

diyaudio.com has some threads on this amp... at least one with volume pot questions/responses.

Frankly, I'd set the fixed gain level, using the pins you've pointed out,
as low as I could (both gain pins shorted to ground) if that provides
enough volume with the computer output maxed... and just use the computer
volume control.

That said, you -could- use a pot wired as a rheostat (http://www.resistorguide.com/rheostat/)
to replace the input 10K and another in series (between the input jack and the DC blocking capacitor)
otherwise, when you turn the volume down you'll short the computer output to ground.

diyaudio is a much better place for such questions though... perhaps some better ideas.

Have fun.

Thanks for your answers, it did help me!;)

[millionreason]

I would use a stereo 100K audio taper (log) with a pair of 1K resistors to keep the signal from going to ground. Look How I set up the audio pots in this schematic (upper left).

http://www.audioheritage.org/photopost/data//500/medium/ScreenHunter_125_Dec_28_16_50.jpg

This schematic is a little bit complicated for me as I'm new to this. I'll take some time to read this! Thanks!