Mesa 50/50 Considerably Weaker on One Side

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CaseyCayce
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Joined: Sun Jan 15, 2017 8:37 pm

Mesa 50/50 Considerably Weaker on One Side

Post by CaseyCayce » Mon Jan 16, 2017 6:32 am

Hey, Boogie Board;

I'm running a Mesa 50/50 Stereo from about the mid 80s, so it's logged some miles. I've had a problem for a while where I have to push the left side almost 3 notches higher then the right to balance my speakers, and over this last week started eliminating possibilities to track down the problem. I re-cabled my speaker cabs, installed all new valves—4 6L6s and 3 12AX7s—but still can't get it resolved. It's not an imbalance in my input signal, because when I have no signal going in—just connected to my patchbay—the natural hum of the amp has to be set at 7 on the weak side side to match 4 on the strong. I'm the original owner and the piece has never gone beyond my rack in the studio, so whatever it is, it's age related rather than road effect (arthritis? Alzheimers?).

Any suggestions for further diagnostics would be hugely appreciated.

Thanks.

Cayce

JMMP
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Joined: Wed Dec 22, 2010 2:57 pm

Re: Mesa 50/50 Considerably Weaker on One Side

Post by JMMP » Mon Jan 16, 2017 12:08 pm

Did you check your speaker cables and speakers? Make sure they are plugged in all the way, and try swapping sides.
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CaseyCayce
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Joined: Sun Jan 15, 2017 8:37 pm

Re: Mesa 50/50 Considerably Weaker on One Side

Post by CaseyCayce » Tue Jan 17, 2017 6:37 am

JMMP wrote:Did you check your speaker cables and speakers?
Thanks, JMMP...

Yeah, as mentioned I re-cabled my speakers and have eliminated all connection related possibilities. I've switched sides and the problem stays consistent with the left output from the amp. It's definitely something internal. I'm hoping to get some 'most likely' components to begin checking and get it straightened out.

Thanks.

synaesthesia
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Joined: Mon Jul 18, 2011 6:11 pm

Re: Mesa 50/50 Considerably Weaker on One Side

Post by synaesthesia » Thu Jul 20, 2017 4:26 pm

Did you solve this? My 50/50 is acting up like this and I have this weekend to see if I can solve it.

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