Loud Hum

Dynasys- No, if you turn off the lights, and the hum remains, it's a ground loop problem. Good thing; you don't have to listen in the dark! You don't need a separate ground for the wiring. In my system, I had a terrible time getting rid of the hum. My Plinius pre-amp had no ground switch (internal cheater?) which helped a little. Eventually I had to put a cheater on everything but the preamp ( I plugged everything into a PSAudio plugstrip,except the power amp. I put a cheater on the plug strip. I still had the hum. I unplugged the cable. Less hum. I put a cheater on the power amp. The hum went away...) I also bought a coax ground cheater to divorce the cable from the ground (you can get the mondial magic isolator from audioadvisor.com for 100 bucks.

I had a similar problem. I solved it by installing dedicated 20 amp circuits.
You've got a lot of amplifiers drawing juice and when they don't get the juice they want, the transformer hums. Not exactly sure why -- I'm a layman when it comes to the technical side and I cannot recall the explanation I was given.
Everything in my system with a transformer, amplifiers, sub-woofer, and even
AC Conditioner was humming. But, when I installed the dedicated 20 amp circuits, all humming stopped. System is quiet as a stone.

I once had a problem with hum. It was caused by Halogen lite bulbs. I asked a few of my knowlegable friends how to get rid of the hum but nothing worked.Since it only buzzed when the lites were on, I thought why not go to regular bulbs. Presto, no more hum. My friends were impressed.
Do you have any halogens in the room or nearby?

Try putting the proceed on the same dedicated line as the Brystons. You may have a problem where the lines at the panel are not on the same phase . If the line now running power to the Brystons is on the right side of your panel and the line powering your Proceed is on the left, this could be the problem.Easy to fix yourself, just shut off the power coming into your panel and check that it is off.