Quote from: Roly on March 27, 2013, 08:11:33 AMJust wanted to comment on this even though we are now dealing with a different model of amp. The gv60 or gv100 power amps are basically copies of later (cathode driven) Musicman amps. The cathodes are not at ground due to the transistors, so the full B+ is not across the tube. Also, the screens are run at around half the plate voltage. I believe this is how these circuits get away with running 6L6's at such high voltages (see Musicman schematics). I believe the higher power Musicman amps claimed 150W from a quad of 6L6.
I also have to say that I'm mildly astonished a) by the manufacturers' claim of 100 watts out of a pair of 6L6's, then b) by the HT voltages shown on the circuit, 585V for the 60 watt version, and 715V for the "100 watt" version.