SS bias pot tweaks?


Anybody out there playing with their bias pots? Is it just me or is somebody else ending up with a better amp than they started with also?
csontos
Csontos - I agree that bias might not be set to optimum on particular amp especially for the best channel match. If you can find sweet spot by listening - great. You might want to measure just to know where you are. It is voltage drop measurement on one of two large resistors (usually around 0.3 ohm) near power transistors to determine current.

Heat sinks in class AB amps are undersized (average music power is only few percent of peak power) so be careful.
Without specific instructions and a quality DVOM to make accurate measurements makes for a foolhardy endeavor. Turning screws and tuning by ear = bad idea. I have done bias adjustment on Classe Dr-8's. The measurement for that amp was a range of 70-96 ma per channel divided by the four bias pots per channel. An infrared gun is handy to measure heatsink temp as well. The amp needed to be powered several hours at idle prior to making any adjustments. I preferred 88ma or 22ma per pot.
Points are very well taken, guys. I do agree you must be very careful but I'm just convinced by my own experience that the only way to pinpoint it is by listening. I've listened to lots of high-end stuff over the years but never heard the kind of sharp spatial positioning between instruments and vocals that I hear on my own stuff. Limitations in source material is simply apparent and not obtrusive or fatiguing. Ambient sound is so present that I can tell I'm hearing "all" of the information. I've been doing this for many years and have never blown an output or fried anything. Incidentally, I wonder if the self bias function in my Meridian 559 is why my other amps sound so much better?
I should mention that having said all that, I would definitely not attempt this procedure on an amp with multiple pots on each channel.
Be careful - my amp is in the shop because I very stupidly shorted something out when I was measuring the bias voltage.

Mark