Well this sucks I'm done with the amps . After 4 hours yesterday and a few hours today I'm about to put my system back together. I did everything I could think of to silence the amps with no effect. Nothing in my room has power to it but the amp and speakers no rca connected just speaker cable with no effect. Something is wrong with my power and all my amps that I've owned are not this sensitive to bad power I've never had a ground loop hum that I couldn't get rid of. Thanks for the responses. I guess I will stick with my rotel amps and be happy maybe buy a new prepro or a Sony 4k projector.