guitar speaker/tube challenge redux

[J. Larry Hendry]

> 2) Martin Czech wrote:
> 
> >  How can one destroy a tube (without an elephant sitting on it)?  Too
much
> >  anode current will make the anode glow (good idea to look at it), but
> >  amateur radio people said to me that the tubes can stand that for a
> >  while (a bipolar transistor or mosfet will die very soon if the SOA is
> >  left so far behind). Tubes can also withstand very large anode voltage
> >  transients/overstress compared to transistors (2nd breakdown,
snapback).
> 
> >  If you do something wrong to a tube amp, either a cap or a transformer
> >  will blow, tubes die slowly (my own experience and that of my amateur
> >  radio collegues, perhaps radio tubes behave different from "audio"
> >  tubes?).

Seems like a slow acting fuse in the plate circuit might be good protection
for expensive output tubes Anyone ever seen a tube circuit fused that way?

Larry Hendry