[DIY] OT: Tube amp disaster

[Martin Czech]

AFAIK tubes are pretty robust. When shortet the anodes start to glow,
usually they can take it for some minutes. If you look at the tubes
you'll perhaps notice some anode surface coloring due to that.

HAM people often report incredible tortures for their PA stages
due to fallen down antennas or impedance mismatch etc.
Transformer less PA stages survive all that, they may degrade, however.

An open circuit should not matter for the tubes, with some exception...

But there's the output transformer. It will suffer from short (heating)
as well from open conditions (resonance will lead to very high voltages,
insulation breakdown or -> tube damage e.g. via feddback windings ("super-
linear" output circuit)).

After removing the push-pull tubes the transformer should be isolated
so that any insulation problem should be detectable.
How does the transformer smell? Burned insulation? Burned wiring, or pcb
(spark gap).


m.c. (no tube expert)