How to get rid of transformer hum?


I have a pair of Pass X600s and an ac line with about 5% clipping of the sine wave. This gives me a large amount of transformer rattle (mechanical hum). I have built a line filter with two diodes and a couple of caps that has gotten rid of 80% of the noise but I'm looking for a inexpensive fix. My power company will not fix the power coming in unless it is clipping by more than 7%. Any suggestions?

Tommy
tommy

Showing 1 response by garfish

Hi Tommy; I'm sorry I can't help you, but you've maybe helped me. I have a pair of McCormack DNA-2DX amps that hum at various levels. I've talked to Steve McCormack about this at length, and he says that most likely there is DC leakage into my AC lines, and that there is nothing they can do about it (is this the sine wave clipping that you mention?).

I have not yet contacted the power Company, but have a hard time believing they would have much interest in it? BTW, my amps are at SMc being upgraded, and I specifically asked them to check out their tendency to hum. Steve has told me that they do not hum in S. Calif.-- probably not enough power to muster up a hum ;>). We'll see. Craig.