First post, by vstrakh
How's the mixing implemented on CT2940, and what are the common failure modes?
I have this card, it plays FM nicely in diagnose.exe, but the PCM (both 8/16 bit) are just barely above the noise floor.
The card has lots of op-amps, mlcc caps and vias, something that might die or crack relatively easy, and I was hoping that since FM sounds is ok, then it's a matter of checking the PCM signal path.
But looking closer it appears that the CQM DAC op-amp (U7) output just goes back into CT2502 chip, so all the mixing happens internally. How it's possible to lose the PCM then? The mixerset shows voice/master levels close to the max.