Try this thread also. Sounds like a ground loop hum, and the hands-down most common culprit is a coaxial cable (TV) feed comming into the same circuit. Had the same problem, and the linked discussion (as well as many other's you'll find) tell you how to lick it -- if that's what's ailing you.
why is this thing humming?
I just hooked up my new mcintosh 207. I made sure the cables arent bundled and what not everything looks pretty clean. But this amp is humming something bad. I rehooked up my rotel 1095 no hum what soever. This is up setting since the reason I bought this amp was the Rotel was supposed to be the wink link. Please help I need my tunes up and going.