Black Plaid
Other Alan!
I still believe that power differences (varying voltage levelss and dirty power) are the main reasons our amps sound better one day than the next.
I'm glad I am not the only person who notices this. I never put it together with voltage fluctuations though!
The reason it's more critical to at least some older amps is they just use a voltage multiplier to get the plat voltage correct, and are expecting voltages from teh dayes off yore.
I think there was an Uncle Doug video on the topic where I learned about this.