Someone flipped my magnets..

Eamonn

Eamonn

New member
I have a pair of Gibson Classic 57 pickups in a LP. I know they are out of phase with one another even though the wiring is stock. In the middle position they are thin sounding but there is no hum. When either pickup is on by itself it sounds stock but there is (what sounds like) 60 cycle hum.

I'm guessing that the mags have been flipped in both pickups. I'd like to return them to stock. These are uncovered zebra coils...if that makes a difference.

I have never opened up a HB pickup so please forgive my ignorance on this matter.


Thanks.
 
Re: Someone flipped my magnets..

if the magnets were flipped in both pups then they would be in phase. if they are out of phase only one magnet would have been flipped.

there are lots of reasons you might have hum but none of them have to do with the magnets or phase. there are magnet swapping tutorials here on the forum, you arent swapping magnets but the process is the same.
 
Re: Someone flipped my magnets..

I refer the honourable gentlemen to the answers given when he posed almost exactly the same question a week ago. https://forum.seymourduncan.com/showthread.php?t=220688

The essential detail - present last week but missing from this thread - is that the guitar is a Gibson LP Studio Faded. Classic '57s are not stock in that model so the pickups have probably been swapped between two Gibsons.

The majority of Gibson pickups installed into complete guitars come with single conductor and braided shield output cable. Hence, phase reversal - deliberate or accidental - is not physically possible except by inverting a magnet in one or other of the pickups.

EITHER somebody already tried that (and you need to reverse the offending magnet back to normal)
OR you have two of the three pickups from a 3HB Gibson LP or SG Custom.
 
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Re: Someone flipped my magnets..

Not the same question at all. A week ago my question was about the wiring. I now know a mag was flipped which poses an entirely new problem. I was basically asking how to I return the magnet to stock.

Thanks for the answer though.
 
Re: Someone flipped my magnets..

It's not at all impossible to reverse the wiring on a braid lead pickup, you would just get a lot of noise because the baseplate and cover would now be pumping noise into the signal instead of to ground.

The OP says lots of hum and noise, right? Well, check to see if one of them has the braid shield soldered to where the center lead should be, and the center lead to ground. If so, there's your explanation...
 
Re: Someone flipped my magnets..

Zhangliqun said:
The OP says lots of hum and noise, right? Well, check to see if one of them has the braid shield soldered to where the center lead should be, and the center lead to ground. If so, there's your explanation...
Click to expand...

Agreed.

It is just that, in over thirty years, I have only once met anyone dumb enough to get that wrong. Ironically, he was a fully qualified, ex-military radar electrician.

The guitar's owner requested that the cables on the neck PU be reversed to correct a phase issue. This is precisely what the electrician did. :smack:
 
Re: Someone flipped my magnets..

I just checked the mags and both positive poles are facing inward towards each other. I also re-checked the wiring and the braided leads are both going to ground.

I plugged it in and both pickups sound full individually but thin and strained when combined.
 
Re: Someone flipped my magnets..

Eamonn said:
I just checked the mags and both positive poles are facing inward towards each other. I also re-checked the wiring and the braided leads are both going to ground.

I plugged it in and both pickups sound full individually but thin and strained when combined.
Click to expand...

Do both p'ups read North in the slug bobbin and South in the Screw bobbin?

Are by any chance 4-conductor or normal braided wire?
 
Re: Someone flipped my magnets..

LtKojak said:
Do both p'ups read North in the slug bobbin and South in the Screw bobbin?

Are by any chance 4-conductor or normal braided wire?
Click to expand...

Yes. N = screw side on both. I'm pretty sure it's 4 conductor.
 
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