wrote:

I was looking at some old 813 tubes that were once commonly used for
Amateur radio transmitters, as the final output tube. While the common
audio output tubes like 6L6 and 807 can produce about 25 to 30 watts
audio output (per tube), running around 300 to 450 volts plate voltage,



** Versions of the 6L6GC made by RCA and Sylvania can be operated in pairs in class B with 700V on the plate and 400V on the screens.

Audio output power can be 100W per pair in this mode, with low distortion.

EL34s can also be used the same way to deliver 100W.

Guitar amps made by MusicMan and Dynacord are commercial examples.


...... Phil