Does biasing the tubes determine the output wattage?

[kiteman]

I was wondering about that. When I biased my Alchemist at 50% (35ma) which is 15 watts per tube it sounds clearer and spacious. Before, I had it at 47ma which is under 70% for 20 watts per tube, I got some warmth and husky sound which is nice but gets hot.

I guess the amp has some cooling problem.

[jim p]

If you bias the tubes cold with a higher negative voltage on the control grid the tubes will run cooler at idle and you will get a greater voltage swing out of the amplifier. But at that point you may have crossover distortion this where both tubes are off and there will be no signal from the amplifier during that portion of the output waveform. To test for the point of crossover distortion you would need to use an oscilloscope and waveform generator to see what the output signal looks like. If you bias hot there should be no crossover distortion and the signal swing of the output will be reduced versus being cold biased so there is some wattage increase with cold bias but you may have crossover distortion.

here are two links on bias http://www.tone-lizard.com/Biasing.htm
http://www.tone-lizard.com/Marshall_bias.htm

[kiteman]

Yea, I know what you mean and I've played quite a bit so far and it sounded good (to me at least).