1941 EH125 Gibson troubleshooting help please

Dennis Waltman · From: Wisconsin, USA

I just bought the subject steel guitar, replaced tuner buttons, cleaned pots and put a new set of GHS lap G tuning strings on this beauty. When I plug it in there is low volume output and it's very much treble biased. The far pot (volume) seems to sweep nicely through the volume but the near (tone) pot does not significantly affect the tone setting. Full CCW on the tone pot also seems to shut off the volume. Neither pot is scratchy and there appear to be no modification to the guitar. Ohm reading across the output jack with both pots fully at CW is 474K Ohm (see photo).

All solder joints look good. Any ideas?

Thanks, Dennis

Chris Reesor · From: British Columbia, Canada

Sounds like an open pickup coil. Disconnect one pickup lead and read the resistance. Should be something like 6K to 12 K. I bet it will read infinity, meaning at least a tricky pickup repair but more likely a rewind or replace situation.
Good luck.
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Dennis Waltman · From: Wisconsin, USA

Thanks Chris,

I unsoldered one pickup lead and found no continuity across the PU. If I unsolder the PU cover to inspect the coil winding is there a spot that is a usual suspect in the open leads?

Dennis

Carl Mesrobian · From: Salem, Massachusetts, USA

I'm not familiar with this pickup, but you might do a visual check on the spots where the thin wire from the pickup meets the wire (possibly single conductor with braided shield) that goes to the controls. On my old Gibson guitars with P-90's the pickup is mounted on a plate and the connections are tape wrapped splices. The white and black wires go to the pickup magnet wire, which is VERY fine (42-43 AWG). The pictures show a P-90 from a "later" date, probably the 60's without the mounting plate.

Are you checking that wire? If you get a typical resistance reading there, then the pickup is probably ok, and there is an open in the wiring from that point on. I would then check each solder joint along the way, leaving the common on one end, and testing for continuity starting from the first solder joint to the next to the next, etc. It could be as simple as a break somewhere outside of the pickup coil.

Picture file

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--carl

"The better it gets, the fewer of us know it." Ray Brown

Stephen Cowell · From: Round Rock, Texas, USA

I might be interested in your old tuners if theyâ€™re for sale.
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Chris Reesor · From: British Columbia, Canada

Dennis, I would suspect the connection between the actual coil wire and the leads which emerge from the metal case, or a break in the coil itself. This is where it gets tricky.
Carl has covered some likely construction details, which will become clearer when the case is unsoldered and open.
If you don't have the soldering skills and tools and supplies of an experienced electronics tech, I'd respectfully suggest you should probably send the pickup to a specialist for repair or rewind.

CR.
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Excel Superb U12, MIJ Squier tele, modified Deluxe Reverb RI, Cube 80XL, self built acoustics & mandolins

Carl Mesrobian · From: Salem, Massachusetts, USA

Soldering magnet wire is definitely a skill that requires a learning curve. Smile

_________________
--carl

"The better it gets, the fewer of us know it." Ray Brown

Dennis Waltman · From: Wisconsin, USA

Thanks all,

I unsoldered the PU cover and could find no easily located open in the fine winding wire or its connections. At this point Iâ€™m going to try and locate someone who can perform a repair or rewind as needed on the PU. Any suggestions?

Thanks, Dennis

Dennis Waltman · From: Wisconsin, USA

Stephan,

I only replaced the plastic tuner buttons and retained the tuning machines.

Thanks, Dennis

Carl Mesrobian · From: Salem, Massachusetts, USA

Jerry Wallace - I haven't used him, but lots of good things said about him.

http://www.jerrywallacemusic.com/

EDIT - after some research I found that this is a P-13 pickup.
_________________
--carl

"The better it gets, the fewer of us know it." Ray Brown

Chris Reesor · From: British Columbia, Canada

Jerry Wallace could be your guy, but if nobody comes up with any others, try a forum search on "pickup rewinding".
I recall a new guy got mentioned fairly recently in that line but his name escapes me.
IIRC, he is quick, does nice work at a reasonable rate, and can handle about any kind of pickup.

CR.
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Excel Superb U12, MIJ Squier tele, modified Deluxe Reverb RI, Cube 80XL, self built acoustics & mandolins

William Rasch · From: Vermont, USA

Tom Brantley does excellent work. 804 467 5887

Dennis Waltman · From: Wisconsin, USA

The pickup is in route to Tom Brantley.

Thanks, Dennis

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