On one leg or two legs?

Don't know where to begin, well:
I was hoping to find interference from my PC or cable, but no luck. I disconnected and unplugged PC, cable modem, wireless router, switched off all breakers, except the power amps- hum is still there.
Tried different speaker- still there
Tried different power cord- still there
Plugged the amp into a different outlet upstairs, separate from the dedicated panel, through the long extension cord- still there.
Hum, or buzz, is very constant in nature and nothing seems to change it. it does sound like a ground loop buzz to me, more, than anything else.
Again, L channel amp hums more, than the R channel with everything disconnected from it.
Hevac1, thanks for your ideas, but in lieu of the above statement, I don't think compatibility of the different components is the culprit.

Jea48,
I don't know why I didn't ask him to move GFI breakers (they are the ones with yellow markings on them?).
Where do you think they should be in the panel?

Did I mention how frustrating that is ?

One last thing- I switched the amps left to right, and the hum moved too. I don't know, maybe it's inherent to that amp? At any rate, hum is there.

Ozzy,
I run them balanced

Maril -- Do try what I suggested with a battery-powered portable AM radio, checking to see how much interference or buzz it picks up in the room, and if it is significant, walking around with the radio to try to track down its source.

How close are your nearest neighbors -- maybe it's coming from them.

Aside from interference being picked up through the air, the one other possibility that occurs to me, given that the amps worked fine before being moved to your house, is that perhaps the mechanical jostling that occurred during the move affected something within the amps. Such as, perhaps, a screw loosening slightly, causing the contact between a metal transformer housing and the chassis to lose its integrity.

-- Al