Bill, you wouldn't want me to come over with my Aloia preamp w/phono stage now, would you? (if you don't tell Andy, I won't ;~). Although I'm not up-to-date with your wiring scheme, I thought that you had planned a dedicated (supplementary) earth ground for the system, via the dedicated circuit box - the AC should not be an issue if you've got this. I believe Extremephono has a point about possible ground loops - one pole in the ground is enough.
As you haven't mentioned any problems with playback via the AAC-II, your efforts should concentrate on the IO --- power supply vs. grounding scheme.
Good luck, and be careful if you go poking around (I mean in the IO unit).
Arooj
As you haven't mentioned any problems with playback via the AAC-II, your efforts should concentrate on the IO --- power supply vs. grounding scheme.
Good luck, and be careful if you go poking around (I mean in the IO unit).
Arooj