Sorry... everyone's probably sick of my biasing questions by now. But I cannot help myself. I was checking voltages in my Fender Vibro Champ and looking at the schematic. I know the Champ is "cathode biased" right? But nonetheless, a 6V6 is still max 12 watts (or possibly 14 watts depending upon the tube), so the same rules should apply with respect to currents, shouldn't they? So when I measure plate voltage, I get about the same as stated in the schematic: nominally 340V. That would mean my absolute maximum plate current should be 12/340 or we'll say about 35mA (if this is class A, then I don't need to take 70%). The cathode voltage at the 470 ohm resistor also roughly matches the schematic at about 24V. That makes the current through the cathod 24/470 or about 50mA, which is much larger than 35mA. That would mean, to remain under the maximum power dissipation of the plate, that the current through the 220K screen resistor must be at least 15mA (and, unfortunately, I didn't measure that last time I had the thing open--duh). Does that make sense?