hotter bias with low plate voltages

[gary]

I would be interested to know whether anyone has experimented with hotter than typical bias settings in cathode biased vvr/scaled amps. I'm making the assumption that if you always run your amp at home/practice levels, then the plate voltage will be nowhere near high enough to cause the tube to reach maximum plate dissipation - thereby affording scope to lower the cathode resistor value. Am I way off base here?

[Firestorm]

What do you consider to be a "typical bias setting?" If you're asking whether you can take a Class AB amp, dial down the supply voltage and rebias into Class A, well of course you can. Whether it will stay in Class A or not depends on signal voltage relative to cathode voltage (and to some degree whether you've bypassed the cathode resistor.)

There is a caveat: just because your idle plate voltage is low does not mean the tubes can't pull enough current to over dissipate, especially if you haven't also scaled the drive signal along with the supply voltage.

[gary]

I was wondering whether it might be another option to consider by those trying to eliminate fizz from their vvr'd el84 power amps

[Reeltarded]

Van Halen dialed the variac to 90vac and cranked the typical -38 ish at 450vdc bias of EL34 to around -80.

Is it what you asked? No, but it might be relevant? Maybe.