Dual humbuckers muted and thin in middle position. Why?

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FluffyDog6

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Have a (new to me) guitar with dual humbuckers.

It sounds fine in either bridge or neck position, but in the middle position it sounds like someone turned the volume half-way off.

Would reversing the leads at the switch on one of the pickups fix this?

Thanks.
 

Steve 78

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Yes, the most likely cause is the pickups are out of phase with each other. The fix is exactly what you say, reverse the leads coming out of one of the pickups. Just make sure the active isn't connected to a shield (shielded wire or humbucker cover) that needs to be grounded.
 

FluffyDog6

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Just make sure the active isn't connected to a shield (shielded wire or humbucker cover) that needs to be grounded.

Um.. I'm not sure what that means.

They are covered humbuckers in a semi-hollow guitar. Just flippping the wires at the switch should be it, right? Or am I overlooking something?

(Since I have to fish the wires out of the F-hole to work on it, I'm not able to really even peek at the configuration before hand.)
 

charlie chitlin

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Not so easy as that.
If it's a typical Gibson style layout, both leads from the pickup go to a volume pot. One goes to the body of the pot and the other to a lug. They need to be swapped.
I guess the quick and dirty, no pot fiddling way would be to pull a pickup, cut the wires and splice them back together, reversed.
 

fatcat

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Not so easy as that.
If it's a typical Gibson style layout, both leads from the pickup go to a volume pot. One goes to the body of the pot and the other to a lug. They need to be swapped.
I guess the quick and dirty, no pot fiddling way would be to pull a pickup, cut the wires and splice them back together, reversed.

NOOOOOO!

Sorry but hearing that makes me cringe.

Swap them at the pots.
 

Gaz_

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Not so easy as that.
If it's a typical Gibson style layout, both leads from the pickup go to a volume pot. One goes to the body of the pot and the other to a lug. They need to be swapped.
I guess the quick and dirty, no pot fiddling way would be to pull a pickup, cut the wires and splice them back together, reversed.

Finally, the forum is getting to MY level!
 

charlie chitlin

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NOOOOOO!

Sorry but hearing that makes me cringe.

Swap them at the pots.
Awwww...come on....what makes one solder joint any better than another?
A little shrink tube and it's all sanitary.
And if the OP is a beginner at this stuff, soldering to pots is tricky.
I swapped pickups on an archtop once by cutting and splicing, saved a lot of hassle and never felt a twinge if remorse.
 

Vizcaster

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Here's an idiotic idea: check and see if you don't already have a push-pull switch on one of the volume or tone pots that would toggle the phase in and out between the two pickups. Some wiring harnesses have the option of phase and series/parallel.

Also, see if you don't have a stereo jack. Guitars with stereo output were often out of phase because the two channels of a twin or DR are out of phase.

Because if your pickups are out of phase and they have normal stock wiring you don't have that many options.

Most humbuckers have coaxial wire where the braided shield works not only as a shield but also the ground part of the circuit. The pickup cover is likely attached to one end of it. If you were to simply reverse the connection at the other end, you would make the pickup cover hot (so it will buzz loudly if you touched it), and it would turn the wiring runs into antennas because there's no shielding.

Imported guitars often have less expensive coaxial wire with a thin vinyl covering and really delicate wires inside that don't behave well being soldered too many times. If it is proper Gibson style wire, then the braid is rather robust but it's also exposed so it quite likely would short out the guitar because somewhere inside the guitar those braids from different leads might touch each other (not an issue as the manufacturer intended if they're all connected to ground, but quite a problem if the braid on one is supposed to be hot). Also I'd hazard a guess that there's a bare wire soldered to the braid of one of the pickups and it's connected to the tailpiece or bridge studs - so if you reverse that particular wire you'd make the strings hot, too (again that noise as if you touched the tip of the guitar cord). So no, rewiring the switch or even the volume pot is not going to solve your problem.

If you are sure that the pickups are out of phase, the best option would be to rewire the pickup with multi-conductor shielded cable (most aftermarket humbuckers come that way, but original equipment probably does not). If you disassemble the pickup you might be able to flip the magnet over to change the polarity of the pickup (lore has it that the Peter Green mod happened accidentally this way, I don't subscribe to that theory). Or, after disassembling the pickup you could reverse the leads where they connect to the coil wires (a delicate job) - If I was going to go that far I'd just convert to four-conductor color-coded shielded cable.

BTW many repair people shy away from hollow-body electrics because of the extra time involved in reassembly. Also you might not have a big enough notch in the center block to get everything in and out of the bridge pickup cavity - you might need to feed it all in and out of the f-hole (I like to use aquarium tubing from the pet store, attached to the pots, to help fish them out and back in again, another tip is to make up a piece of cardboard with the same hole pattern as your guitar top, so that when you solder the pots the wires want to stay more or less in that configuration).
 

schmee

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Yes you are likely out of phase, just reverse ground and hot leads on one pickup. If you have a choice I would do a pickup that doesn't use that metal woven shield. If you use that as how you have to watch it doesn't ground out on some thing or shield it somehow.

BUT, be aware that two humbuckers tend to sound a bit that way, "hollow" even when phased correctly.
 

moosie

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Here's an idiotic idea: check and see if you don't already have a push-pull switch on one of the volume or tone pots that would toggle the phase in and out between the two pickups. Some wiring harnesses have the option of phase and series/parallel.

Also, see if you don't have a stereo jack. Guitars with stereo output were often out of phase because the two channels of a twin or DR are out of phase.

Because if your pickups are out of phase and they have normal stock wiring you don't have that many options.

Most humbuckers have coaxial wire where the braided shield works not only as a shield but also the ground part of the circuit. The pickup cover is likely attached to one end of it. If you were to simply reverse the connection at the other end, you would make the pickup cover hot (so it will buzz loudly if you touched it), and it would turn the wiring runs into antennas because there's no shielding.

Imported guitars often have less expensive coaxial wire with a thin vinyl covering and really delicate wires inside that don't behave well being soldered too many times. If it is proper Gibson style wire, then the braid is rather robust but it's also exposed so it quite likely would short out the guitar because somewhere inside the guitar those braids from different leads might touch each other (not an issue as the manufacturer intended if they're all connected to ground, but quite a problem if the braid on one is supposed to be hot). Also I'd hazard a guess that there's a bare wire soldered to the braid of one of the pickups and it's connected to the tailpiece or bridge studs - so if you reverse that particular wire you'd make the strings hot, too (again that noise as if you touched the tip of the guitar cord). So no, rewiring the switch or even the volume pot is not going to solve your problem.

If you are sure that the pickups are out of phase, the best option would be to rewire the pickup with multi-conductor shielded cable (most aftermarket humbuckers come that way, but original equipment probably does not). If you disassemble the pickup you might be able to flip the magnet over to change the polarity of the pickup (lore has it that the Peter Green mod happened accidentally this way, I don't subscribe to that theory). Or, after disassembling the pickup you could reverse the leads where they connect to the coil wires (a delicate job) - If I was going to go that far I'd just convert to four-conductor color-coded shielded cable.

BTW many repair people shy away from hollow-body electrics because of the extra time involved in reassembly. Also you might not have a big enough notch in the center block to get everything in and out of the bridge pickup cavity - you might need to feed it all in and out of the f-hole (I like to use aquarium tubing from the pet store, attached to the pots, to help fish them out and back in again, another tip is to make up a piece of cardboard with the same hole pattern as your guitar top, so that when you solder the pots the wires want to stay more or less in that configuration).
Excellent post. Yes, if OP has stock Gibson wiring, it's a tough fix. No way around it.

What bothers me is how it got this way... begging the question already posed... are you SURE they're OOP, without special switching to make them that way?
 

Peegoo

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Get a flashlight and a small inspection mirror (a dental mirror works too) and have a peek in there through one of the F holes.
 

AJBaker

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Instead of flipping the wires, you could also just flip the magnet inside one of the pickups.

Pics would be helpful in any case.
 
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