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Original Message
Odd hum issue - suggestions ??
Posted by rogerh113 on May 30, 2017 at 15:41:04:
I've been going through an amp to be my backup, and am stalled at an odd hum issue. Turn the amp on and it has a fairly loud hum. Touch the front panel, or any of the amp chassis, and it goes away. Run the amp ungrounded, and much (but not all) of the hum goes away.
I thought it might be a bad internal ground. Sure enough, the ground lead was secured at one of the inside foot screws. Of course, the chassis is enameled, so the ground lead was against enamel. Cleared the enamel, used a star washer, and re-secured the ground lead. No improvement - if anything, it is a bit worse. Except if you touch the chassis, in which case it still goes away.
Does anyone have any suggestions, or have encountered and solved something like this. I am assuming that it is something really simple...
regards -- Roger