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Guitar Preamp

PhilNorris

Apr 30, 2015
1
Joined
Apr 30, 2015
Messages
1
Hi People,

I have a preamp - its a Mesa Boogie Triaxis. It's started to rumble on the output. That's the best way to describe it, like distant thunder, some standard component that is shot, loading up with a charge or releasing it sporadically. It still works, sound comes thru it, but I can't really use it with the rumble for anything serious. The guy who used to fix it has moved away, he once said that it was typical for those XXXXX's to go like that.

Here's a link to the schematic

http://www.schematicsunlimited.com/...triaxis-amplifier-schematic/download/ODk4Nw==

Does any body have an idea what kind of component might be a candidate? I suppose I can test some components, I have a scope (although I'm not sure how to use it yet). It would sure be cheaper to find out what is causing it and fix it myself.

Thanks.

Phil.
 

Arouse1973

Adam
Dec 18, 2013
5,178
Joined
Dec 18, 2013
Messages
5,178
My first thought would be the power amp tubes or a faulty power supply capacitors. Also have a look over the PCB and see if you can see any dry joints.
Thanks
Adam
 

Skezza

May 3, 2014
15
Joined
May 3, 2014
Messages
15
Sounds like the pre-amp tubes to me. Do you have a tube tester?
 
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