Loud Hum

Is it dimmer hum of ground loop? Good explanation at[http://www.audioadvisor.com/store/productdetail.asp?sku=TRIBGG1&product_name=Ground%20Guard%201%20Ground%20Loop%20Eliminator] Turn off dimmed lights. Hum? Unplug cable. Hum? Ground loops (caused by the cable being grounded at a different potential from your electrical cable) can also be at your equipment. Unplug all video RCAs. If there is still hum, use 3 to 2 prong "cheater" plugs from the hardware store to remove grounds from all bu preamp. If the hum is from video you may need cheaters and cable ground isolator on video grounds.

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.