F-50 Adjustable Bias Pot

Can anyone tell me exactly where to put a trim pot in the F-50 for adjustable bias? I can't find a schematic anywhere and I have searched all over for info but can't seem to get any specific to the F-50! I would much rather hear from someone who has done this mod instead of trying to poke around and experiment with my amp. I do work on amps so I am familiar with the hazards and the circuitry but I generally work with a schematic. Thanks!!

Mesa will email you the schematic if you call them.

if you find out i would quite like to know cheers andy