Mike,

The 811 has a very high amplification factor, and was designed for Class
B operation with no bias, or just a little bias at maximum plate voltage
(i.e. -4.5 volts bias @ 1500 volts plate). For this reason the 811 is a poor
choice as a single ended class A audio amplifier. The brother to the 811 is
the 812, and this dude is more suitable for what you are wanting to do
because the amplification factor is much lower.

It would be interesting though to play with that 811, and with a
suitable driver circuit, you could definitely make a lot of noise. Now
running grid current for 1/2 the audio waveform will require a very low
impedance driver. It remains to be seen if you can get low distortion out of
such a setup even when resorting to that dirty word for SE triode amps:
negative "feedback".

Sell that 811 to a ham operator, and look for a low to medium mu triode
instead.

Regards,
Jim


"michael Mueller" wrote in message
thlink.net...
Hello all./ Just got back from the TRW swap meet, Scored a dozen 807's a
few with ceramic bases. Big question though, I also bought an 811. Why"
, because it was nos, in military box , looked really cool etc etc etc,.
Doe any one have a schematic for an amp with this tube.
Thanks
Mike M