Can bad tubes cause "buzzing or sizzling" sound?

[Rotti]

I have an old Silverface Fender Super Reverb. Lately I'm getting a buzzing sound when I hit a certain note. I'm not sure if it's something loose on the amp itself or if it's a buzzing or electrical sizzling type sound from the speakers. I tightened all the screws I can find and I just can't locate the source of the buzz. Could it be the tubes are done? I had the caps and all the tubes replaced about five years ago. I've played the amp regularly and I've been playing the amp a lot for the past six months, like every day and I'm playing it loud. So can worn out tubes make a buzzing or frying type sound?

[sitting duck]

Well, the simple answer to your question is yes....

I had a similar sound on my amp recently - only on certain notes or frequencies though, and it turned out to be a bad cap. But I'd definitely start with the tubes...