Grounding Hum

I had a hum coming thru my preamp from a little 12V transformer used to power something unrelated that was too close to the pre.....look around the unit for anything that might cause the problem. Also turn off any dimmer, automatic light sensor and flourescent fixtures anywhere in the house. (auto light sensors and dimmers can create havoc).

Is the IC that runs from your preamp to amp shielded? I recently had this same problem and discovered that it was said IC and not the TT ground. Switching to a different IC did the trick for me.

It's Monster Cable interconnect cable, if that helps. Besides taking the cable apart, is there a way to tell if it's shielded?

I finally (3+ days) figured out. I pass along this update in the hopes that it helps someone else out. The source of the hum wasn't grounding at all. It was airborne RF given off by a Kodak camera dock in a distant room. All I can figure is that the electrical circuit for that device went through a wall behind my stereo system.

A big thank you to all those that responded.

Never mind what I said in the previous post. The buzz returned. After venting my frustration, I went to turn the volume up on the preamp, so I could the noise while I went around the house searching for the source. When I went back to the preamp, I inadvertently touched the faceplate, thereby grounding it, and the hum stopped. My conclusion is that the preamp itself is having a grounding problem, that only be heard when the phono input is selected. So the issue becomes one of grounding the preamp. Any suggestions? I don't want to have to act as the ground myself...