A Stupid Idea
On Apr 18, 11:48*pm, "Watt? Me worry?" wrote:
Hi RATs!
The reason a tube sounds good is the circuit it is in, if it ever
sounds good. Not because it was "designed" for low (audio) frequency.
Low frequency is not a huge technological leap, unlike GHz, for
instance.
I am using old TV horizontal amplifiers, 6BQ6, My music is not as
demanding as kicking the electron beam across a CRT.
But, having a ten watt continuous plate rating is a bit less limiting
when the tube is also speced for 500 watts for short periods.
It doesn't matter what the tube was designed to do. If you put it in
an audio circuit and like what you hear, it is an "audio" tube.
No rules for us fools.
They built specific audio, HF RF, VHF/UHF RF, and sweep tubes for
good reason.
Audio types were designed for linearity and to operate their screen
grids at close to the plate supply voltage to make ultralinear
operation feasible.
Some smaller transmitting types are perfectly okay for audio use,
with others it's bad practice when any others are available. The 4D32
is an especially bad choice, plus being rare. The 807 is a decent
choice, as is the 6146 if a separate screen supply is available.
Ultralinear operation of them requires an output transformer with
screen windings.
Sweep tubes are in the same predicament. They are expensive because
the CB keyclowns still run a lot of 11 meter amplifiers with them.
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