McIntosh hum problem

Ligi,
I tried different outlets, cheater plugs and no change. Units are in a different room well away from cable TV. Seems to be a problem with noisy power transformers. Thanks to all for your advice.

Those transformers should not be that loud. You need service as a problem prior to the transformer hooup may be creating the noise.

Thanks Ligi for the advice !

If you've narrowed it down to a transformer hum, try to find which circuit the amplifier is running off of. Then check the circuit breakers in the service panel.

Chances are that your amps' circuit is on the opposing phase of some of your other audio circuits and therefore generating some AC noise thats affecting the transformer. Have an electrician move all of your audio circuit breakers in the service panel to the same phase of 110 volts.

I moved all dedicate audio circuits to the same phase and that cured my transforer hum.

Thanks for the advice Stehno and I will check this out.