Peavey Classic 30 - Tube failure?

[Ard]

I own a Classic 30 for several years and sometimes wondered if it wouldn't be time to change out the tubes, after reading about that, but never did that - yet. Being very happy with the great sound from the amp I thought just leave it as it is. While rehearsing yesterday I suddenly heard a loud squeal which left me with no sound at all.
Changing from guitar Input to Effects return didn't change a thing. The power tube at the far left doesn't glow, so could this indicate a tube failure of that particular one? Thnx for your advice!

[bnwitt]

Of course. Re-tube your amp now. The bad thing about pushing power tubes beyond their rated hours, is they can short and take out other components.

[tubeswell]

Yep those EL84s need retubing about every 12 months (if you play it every day). Put a new quad in.

[Ard]

OK guys, thanks for the quick reply.

I've ordered 4 JJ's and will let you know the results.

[CharlieP]

You may also have a bad fuse. Bad power tubes can blow fuses.

[Ard]

You may also have a bad fuse. Bad power tubes can blow fuses.

After finally receiving the new tubes and installing them late in the evening yesterday I soon found out to still have no sound. But alll tubes glow now so tonight I will dig into it again and check the fuses as you suggest.

[drewl]

They really run these too hot.
I always install a bias pot and set the bias where it should be when I fix these, just did one last week.
Anyway, check the screen grid resistors on pin 9 of the output tubes. When they go they often fry these resistors causing the tubes to light up but not amplify.

[Ard]

Final update

There also was a fuse blown indeed, also replaced it and again enjoy the great sound of my Classic 30.

Thanks for the help you've been giving!

[CharlieP]

Rock On! Glad you have it fixed.