Try installing a better quality dimmer - some of the "better" ones have RFI filtration caps. etc. so they output less radiated noise back onto the AC lines. I had this same problem for years, & didn't discover the source until that old round-knob dimmer finally failed & was replaced. The new one is a toggle switch type, but price was comparable BTW. Also I have seen little filters available that you can install across the AC line input & line output. I don't know the manufacturer, but someone here probably does? It appeared to be a quality cap. & a series resistor package, something like 0.1uF in series with 47 ohms?
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!