Help with Mark 3

[boogiemanmark3]

I own a Mark three purple stripe simulclass. As we all know the R2 channel is a good bit quieter than the other 2 channels. I put on my amp today and R2 is normal and i have lost clean and lead. The clean is quiet and compressed and the lead is quiet and thin sounding. The R2 channel is super loud and full. After letting the amp sit being on for hours everything returns to normal. The lead is full and louder than r2 as is the clean. I have checked all the pre amp tubes and all are good. Can you guide me to what could be the possible problem.

 

[Restless Rocks]

I would say off hand to check the R2 relay and the LDR's.

 

[boogiemanmark3]

Thanks for the reply, but if the R2 has not been affected by whatever has gone wrong, is it that you think that it may be the R2 relay is affecting the other 2 channels?

 

[Restless Rocks]

Real difficult to diagnose an amp I can't look at but just imagining scenarios which might cause your symtoms. The R2 relay along with an LDR attenuate the signal when R2 is engaged. Now if this were to fail to disengage it could attenuate the signal for R1 and Lead as well even when the R2 boost has kicked out. Again just a guess. The schematic is not completely accurate for the R2 part of the circuit. If you are not familiar with normal trouble shooting techniques to trace a signal path you may be better off to find a good tech.