I'd like to post what I discovered last night. First off, like most people, my cable was 80% of the problem.

I still had a little hum left. I have a junk Sony "ES" receiver, used as a pre-amp. Incidentally, will the 997 EVER be released!?! On the back, it has a little grounding screw. I connected a wire to it, and connected it to my ground, and immediately, no hum at all. Dead silence.

The Sony pre-amp has just a two pronged plug, so I wonder if that's the problem. Granted, I'm no electrician. All I know is what I've learned from Google for the past few weeks.