I have 2 Parasound amps which power my back four speakers in my HT; they are each 125 x 2 ; the side speakers hum appreciably; the back ones hum alot less, but still present; I have 500$ power cords in each; a recently purchased noise harvester from PsAudio. Is this the famous "ground Loop" problem or is this a problem with the amp ?? Thanks. JCB PS My Parasound 200 x 3 amp (fronts) does not hum at all.
Sounds like it to me. If the amps have balanced inputs, use them. If not, start by disconnecting any coax for cable or sat. If this stops the hum you need a ground break or try a cheater plug on the amps.