I've searched the forum but come up dry so far.
I've had a pretty major hum problem, so much so that I gave up on using the amp.
Construction is typical/stock, with the Edcor transformers others here have used. Chassis is by Tom McNally so layout is the same as dozens of others shown here.
Long story short, after trying several things I finally thought to just short the inputs and it's solid-state silent. With the inputs open, it's very loud. With the inputs connected to a passive pre it's quieter, but still loudly humming.
The wiring looks almot exactly like this amp of Tom's:
http://www.diytube.com/phpBB2/viewtopic.php?t=5150
The only difference I can see is that IEC inlet ground (not neutral) is grounded at the chassis and at J6 as someone here said it must be, even though Tom's isn't that way.
Can somebody suggest how to go about figuring out how to break the ground loop? Is it safe to ground the IEC connector to the chassis only and not J6? I don't want to change something and try it out only to empty a fire extinguisher on it.
Thanks for any help.