I can't say I understand all of that, but it's good to know! I haven't had a chance to check the breaker box yet, but as far as location, it is about as far away as possible.
I'll selectively pick your suggestion to use larger size wire as a recommendation to use esoteric power cables, eh?
One thing I just thought of, I should try plugging the Onkyo directly into the outlet and see if I'm getting the same result, right now it's running through a surge protector. Methinks that could potentially cause a problem, yes?