...I actually finished my pair of monoblocks!
Pictures to follow, but I do have a question for those of you that have completed these amps already.
Earlier in the "It's Build Time!" thread I asked a few questions about reducing the 60Hz humm back when the amplifiers were electronically complete, but without a chassis. I found that I hadn't properly grounded the transformers to the safety and signal ground. Once I did that the amp was silent at idle...
However, now that the amps are done the slight 60Hz humm is back. The metal top panel, and the transformers are grounded to the signal/safety ground. I've found that directly connecting the line-level input shield/ground directly to the amplified signal ground reduces the humm by about 50% at idle (on my chassis that requires about a 2-inch jumper wire, which short circuits the long leads that go to the shield/ground terminals on the PC board.
The other element that might be limiting me is that my input shield (that is connected to one of the ground plane terminals on the 11-position terminal strip) lays right on top of two of the input capacitors...could that my my 'humm antenna?'
I'll move the input shield lead away from the caps and report back.
To be fair, the humm is very minimal and only noticable at idle...but I'd prefer if it wasn't there at all. Yellow_Light_Colorz_PDT_17
Thanks!
drew*