I recently finished bringing a 1963 Fender Showman back from the dead and I used all the original transformers. All voltages check out perfectly but when I power the amp on (in standby) I can hear the power transformer humming and vibrating like a high voltage power station. It vibrates the chassis and when I turn off standby, I get a little pop and the buzz is transferred through the output to the speaker. It's not overly loud and I can play through it on a gig fine without it effecting the sound. That said, I'm concerned... Any advise? Maybe re-pot the PT?