Blew up the Krell S-300i

[Poultrygeist]

One thing I've learned is how robust and reliable tube amps can be. I have a Rotel/Martel EL-84 that's been going strong since the 1960's and I doubt it's ever had anything other than a few new tubes. Just over the past 20 years I bet I've lost close to a dozen sand amps. Even the slightest power surge can take out a solid state while a tube amp can go unscathed. Steve Deckert says on his website that negative feedback in the case of solid state devices is often the only thing keeping the transistors from exploding all over the inside of your amp. Someone once said you won't find a tube amp that sacrifices it's life to save the fuse.

Point to point hand wiring as often found in simple circuit SET tube amps is far easier to trouble shoot and repair verses complicated solid state PCB's where a cold solder joint on a machined board can be almost miroscopic.

Biasing push pull tube amps is necessary maintenance for reliability purposes but is not required on fixed bias SET amps. Some might consider changing tubes a repair like changing brake pads on a car but it's way too much fun to be classified as a repair. I know guys who can't wait for a tube to go bad so they can relive the pleasure of shopping and trying something different. I can guarantee rolling tubes is more fun than rolling cables and cheaper in most cases plus no one will question that it sounds better.

Tube techs are available even in smaller towns. You will find one in most music shops that sell guitar amps. Repairing an audio tube amp is the same as repairing a guitar tube amp. If you know a retired TV repairman chances are he's a good tube tech as TV's from the 50's and 60's used vacuum tubes.