JCM800 pots change failed

[phos81]

Hi, I changed all the pots in my amp and now the volume is really really low. I respected all the same pots resistances but I changed some of the log 1meg pots for linear pots. Any ideas where could I check first to find the problem?? What can I test??

Thanks,

[g1]

JCM800 is a series, not a model. What is the model # of your amp?
If it was working properly before, than you most likely made an error in your wiring, or installed a new defective part.

[phos81]

Just found the error, wrong wiring, thanks for the answer.

[Helmholtz]

Was it really necessary to replace all pots?

It typically suffices to disassemble the pots and clean the track and all metal contacts with Deoxit on a Q-Tip.

[Chuck H]

Was it really necessary to replace all pots?

It typically suffices to disassemble the pots and clean the track and all metall contacts with Deoxit on a Q-Tip.

Agreed. Were all the pots bad? I've owned four Marshalls from that era and as I recall the pots were of decent quality. I think I still have a couple of those pots leftover after a modification I did to one of those amps. They're perfectly good, so I kept them.

Restoring the originals would have preserved the original tapers too. Looking at the pots in there now I don't imagine they're of better quality than the originals.