Yes, even if I can only hear it when nothing is playing.
The two types I have had to deal with in practice in recent years is EM and hiss from noisy or aging tubes.
EM inducted noise really bothers me and I have zero tolerance. I suspect it affects sound quality even at levels not easily heard in practice. Mu-metal shielding around my step up device was the solution. Hiss from noisy tubes can also bother me but not as much.
The two types I have had to deal with in practice in recent years is EM and hiss from noisy or aging tubes.
EM inducted noise really bothers me and I have zero tolerance. I suspect it affects sound quality even at levels not easily heard in practice. Mu-metal shielding around my step up device was the solution. Hiss from noisy tubes can also bother me but not as much.