I had the same problem when I installed a Krell 300i into my system. I started disconnecting interconnects,etc one at a time and it came down to the only piece that had a 3-prong cord which was ny new Krell at the time. Using a cheater plug cured the problem, but shortly thereafter I purchased a Tice Elite plc and no longer need the cheater. Now everything is real quiet.
Amp "Hum" caused by dimmer switches
I just recently got an Acurus 100x3 amp to drive the front 3 speakers of my home theater system and I am disapointed to find out that my room light dimmer switch is causing a very noticeable "hum" that can be heard from the listening position when no audio signal/ low passages are present. I did not have this problem using the amp in my harmon/kardon receiver. I do not want to remove the dimmer and go to an on/off switch and do not have the money for a power conditioner. Am I out of luck and have to resell the amp? I bought it used from this sight so I can not return it. The amp sounds very nice when the lights are not in use. I'd love to get some sound advice! Thanks!