Why 6L6s running so cool?

[Randall]

I have a Fender 30 on my bench. It is a 6L6 amp with lots of pull pots for channel switching, boost, etc. It's biased at 22mA @ 417v on the plates. The schematic shows -46v for bias. Cranked all the way, I can only get 39 -40mA at idle. Anyone have an opinion on if/why Fender wants this amp to run so cool?

http://www.webphix.com/schematic%20heav ... _schem.pdf

[Randall]

My suspicion has been confirmed on another forum by one with experience with this amp. It is running cool because the break up was designed to come from the preamp, which it does quite well actually. They wanted the outputs to handle whatever the over driven preamp throws at them and stay clean. Makes sense.

[martin manning]

I think that biasing to around 50-60% of max plate dissipation would still be desirable to avoid un-musical crossover distortion. At 420V that would be 35-43 mA. In biasing, the current is more important than the voltage.