mkay, that was a mouthful.
I'd like to upgrade my quad amplifier by adding a 3 channel mixer controlled by an MSP430. remote control, display, internal health check all these will be added one at a time.
volume levels for the channels - PC (front & rear), spdif in (front), line in (front) and for the front-to-rear pan will all be set via a few PGA2311 chips via SPI.
my first thoughts have been laid out in the following schematic [1]
I thought of placing the project here for peer review. if you see anything stupid in the audio circuit your comments are more than welcome.
[1] https://raw.github.com/rodan/ampy/master/hardware/mixer.png