05-12-2016, 02:32 PM
(This post was last modified: 05-12-2016, 02:37 PM by Diabolical Artificer.)
Played some music through it today and whilst it didn't overheat, the LH channel was a lot warmer, so the problem has followed the pre-amp board. Could it be I'm just no setting it right? I've been setting it with the input's shorted, volume controls to 0 after letting it warm up for a while.
AFAIK the amp is the same as schematic apart from Q4/5 have another cap (4N7) from base to emitter, oh and the diodes and resistors under the board. You'll see that one side isn't used, it looks like the other half of the amp, (can't remember whether it's the neg or positive side) has provision for another pot the same as VR1. See pics -
jpg 1091 shows pre-amp board.area around Q4/5, which are the Q's near the blue pot (VR1) and QC label. Underneath this are pads for the pot I mentioned. Pic 2 jpg 1091 is the underside flipped 180 deg through it's long side. Pic 3 is looking through the board of the same area. Pic 4 is the op amp end.
I've looked everywhere I can think of and tested all R's/C's etc, what should I be looking/testing for Mark? Thanks for your help on this, Andy.
AFAIK the amp is the same as schematic apart from Q4/5 have another cap (4N7) from base to emitter, oh and the diodes and resistors under the board. You'll see that one side isn't used, it looks like the other half of the amp, (can't remember whether it's the neg or positive side) has provision for another pot the same as VR1. See pics -
I've looked everywhere I can think of and tested all R's/C's etc, what should I be looking/testing for Mark? Thanks for your help on this, Andy.
