Well, I tried the above, bypassing the audio connection from the main board and routing the input and output signal via X4 and X5 on the volume board instead. I set the input channel count back to zero and the power up input channel back to zero. Unfortunately I get no sound. just a little distorted music when the power is off, which mutes completely when the power is on.
I don't see anything wrong with my build. I can swap in another muses chip, but the soldering on that looks good to me. I imagine the firmware chip is okay since I can set the remote keys and parameters.
If anyone has ideas regarding what to try next, I'll gladly entertain them. I've never had a DIY audio build failure, and I am hoping to avoid a failure here.
Any progress?
I'm in the same situation as you.