I have a problem with my a15mk2
lots of crackling on the speaker (tried different cabinets 8 and 16ohm same problem)
even when the volumes on both channels are down
the crackling is not on the send of the pre amp
so i thinks it s the power amp
i check all the measurements: everything is in the 10%
exept pin 1 on v4
its 271 and it has to be 171 in the schematic
any idea what the problem could be?