F
Fleetie
Enthusiast
You must open up the amp, switched on and running, after it has been on for quite a while, say an hour or two, as warming up DOES affect this.This sounds interesting. Care to elaborate on how this manifest itself and the effects of it? Also - is it risky?
Adjust the small trimmer potentiometer mounted to the top of each of the left and right PCBs, while holding the 2 probes from your digital millivoltmeter on to the 2 test pins (very small and close together, so tricky). I did on my own, but it might be easier with a friend or 2 mini-croc-clip-leads.
You must make the voltage be 11mV (0.011V). You need to have a very light touch with that screwdriver! Move it SLOWLY and carefully.
Too much bias and your amp will run hot.
Too much OR too little bias will cause your amp to be non-linear, or even clip early, making a really nasty sound instead of nice undistorted music.
BE CAREFUL; THERE IS MAINS VOLTAGE ACCESSIBLE IN THERE! RATHER ALARMINGLY ACCESSIBLE, I REMEMBER.