My Deliverance II 60 makes a mechanical buzz when I take it off standby. It seems to correlate volume-wise with the buzz I can hear through the amp, meaning if I change the outlet to one that has less audible buzz through the speakers, the mechanical buzz I can hear from the top of the amp is reduced as well.
The amp also just has a general buzz level that’s significantly higher than my other amps plugged into the same outlet.
I could ignore the mechanical buzz, but I think whatever is causing it is causing the amp to have an unacceptable level of buzz from the speakers.
Update: I took the metal cover off the back to listen more closely. The buzzing seems to be coming from both transformers as far as I can tell, or from the circuit underneath the chassis. It’s actually pretty loud (physically/mechanically).