> Most of the tube designs have been significantly "over engineered".
> That is, the tubes have excess plate dissipation for the power output
> and grids that will take a significant beating.
What you are saying is tube amps would fail if they were not "over
engineered" but assuming you are correct and they are, then they are
in fact more robust so reality trumps theory.
3-500z with 20 w. grid dissipation is a tube you pretty much have to
deliberately damage, in order to damage it.
I don't know how often unobtainium FETs show up at flea markets but
you can often find tubes out of production--3-1000z, 4-1000...sure
they may not be cheap but at least they are there. Most of the amps I
have seen with tubes that become unobtainium were goofy one-offs that
should have never been made. Stick to buying an amp that uses a tube
that is also used in amps made by a number of other manufacturers and
you'll probably never be hung out to dry.
> Given proper design and protection, modern solid state devices will
> last a lifetime unlike tubes that *will* need to be replaced due to
> filament/cathode aging. Transistor amplifiers don't suffer from
> catastrophic arcing and certainly don't represent the electrocution
> danger of tube amplifiers.
Dangers only to hams who don't know what they are doing. I guess it
is easier to make a s.s. amp appliance operator idiot proof but making
one as bullet proof as a tube amp costs a fortune. The Dishtronix
amp, about the only s.s. HF amp I have seen that comes close to being
on a par with a 1.5 kw tube amp in a number of ways is around $10,000.
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