How do you guys ground the board to the chassis? Do you ground J4-3,4, or 5 directly to the chassis? The standoffs are isolated, right?
FYI, I just got done building a stereo Eiclone, e.g. two boards sharing a power transformer. I get an audible buzzing through one of the speakers when hooked up to a CD player. The buzzing seems to follow the input wire from the CD player which suggests that it might be the source. However, I don't get such a buzzing from the CD player when hooked up to other amps using the same cable.
I have the two boards grounded at a single point on the chassis from J1-4 terminals. I also grounded the CT of the PT at the grounding point rather than connected to a board. Could the high current going through the grounding point cause this (I usually ground CTs along with the - term of the first filter cap with input grounds donwstream when I p2p wire)? Should I route the CT to the board?
Thanks for you thoughts,
Min