Mesa Studio .22 Rebuild?

[fsmith]

I was just given a Mesa Boogie Studio .22 of unknown quality and was told if you can fix it you can have it.

So I played with it this weekend and know this about it now.

The presence knob has been broken off. The other pots are scratchy while adjusting.

There was some broken glass from a tube in the bottom so I'm pretty sure at least one may have been replaced. I'm not sure if the others are original, they are Mesa tubes though.

The overdrive channel will drop out after about 3 minutes of playing. If you switch to the clean and back it will more often than not come back. Only to go out again a few minutes later.

Any ideas if I am looking at just cleaning and replacing the busted pot, a new set of tubes or should I put it in the shop for an overhaul? Overall it doesn't appear to have been abused to death, just old and not used in a while.

I'd like to keep it as a spare or something for my step-son to use.

Any leads on where I should send it if that's the most popular option?

thanks,
fred

[John Phillips]

Replacing the Presence control should be easy - they're panel-mounted on Mesas. The channel-switching problem sounds like a faulty relay - not a huge job to change, although you will have to get the PCB out (or at least lift it). Finding which one is the trick though...

The other thing to check while you've got it apart is that there isn't any charring damage on the PCB around the power tube sockets. This is a known problem with these amps after very long periods of hard use - the tube sockets are mounted directly on the PCB with no means of heat dissipation. If there is, you may have to bridge any damaged traces with solid wire - but it doesn't sound like this will be the case if the amp is still basically working.

Not bad for free, anyway. :)

[clay_finley]

Make sure the FX jacks are making a good shorting contact by bypassing using a guitar cord in them.

The board does get hot. Also, there are some carbon comps on the board close to the power tubes. They'll go bad (drop-outs or volume-drop) when they get hot. Try replacing them.

There was also a revision to the early ones to correct a power supply problem.

[Blueser]

What about calling Boogie, and getting an estimate, and having it professionally repaired? I think that would probably be your best bet.

B