20/20 crackle problem

[lost_cause_bb]

Hi, I'm looking for some advice on trouble shooting a crackle problem I’m having with my 20/20

things I have tried or observed....

- I only get a crackle on the left channel. (right channel is fine)
- I cleaned the volume pot and presence pot, no effect
- I changed all the tubes, no effect
- The crackle is only noticeable when you're not playing
- the crackle doesn't get louder with the volume
- it crackles with and without a preamp being used

any suggestions ???

thanks....

 

[disassembled]

Did you replace ALL of the tubes? Maybe you should try swapping the tubes from one side to the other.

Does it make noise without a cable plugged in?

Greg

 

[lost_cause_bb]

Hi Greg,

Yes I swapped the tubes left channel and right channel with no effect, and it doesn't matter if there is an input cable plugged in.

I appreciate your help

 

[disassembled]

Maybe a bad cap or a bad solder joint. It's hard to diagnose unless you really get in there and start trying to find the culprit.



Greg

 

[tedsticle]

If your still having problems just call Rich at Mesa Boogie... Super nice guy and very helpfull.

 

[Monsta-Tone]

I had the same problem with my DC-3.

It ended up being burned power tube sockets.

I replaced all of them and found one with a broken filament leg on the socket itself.

All of the noise went away after the socket change.

 

[lost_cause_bb]

thanks for your advise !!