Soundcard amplitude

[Douglas McDonald]

I have a program that mixes two frequencies and plays them just like DTMF but not telephone freq's. That works great. Now I need to control the amplitude to .07,.15,1.4,2.07,3.07 and 3.37 volts rms. Is there away to do this on code?

Thank you
Doug

[Peter House]

I am sure there is a way to control the voltages RELATIVELY.  I am pretty sure you will not be able to control the absolute amplitude without some type of calibration procedure.

[Robert Eaton]

I am sure there is a way to control the voltages RELATIVELY.  I am pretty sure you will not be able to control the absolute amplitude without some type of calibration procedure.

Or with some kind of fancy sound card like this one:
http://www.renkus-heinz.com/easera/easeragateway.html

[Douglas McDonald]

I keep coming back to this. I really want to use a pc sound card and a geniric built in one, AC97 type. but for now I've moved to a hardware solution. Using a dsPIC MCU I can do every thing I need in firmware as the dsp part has some great active filtering. The DTMF stuff is easy its the amplitude at different frequencies thats was killing me. With DSP and the filters I can make them all exact for DAC output.

Thanks
Doug