Is it possible to change a pups magnetic polarity?

[rmcfee]

I have a Strat pup (from a Godin guitar - fantastic sounding single coil) that I want to use with another Strat pup but I would like to have hum cancelling when they are on together.
The pup in question has a bar magnet on the bottom attached with wax and the usual 6 rods (like any Strat pup).
Is there some way I can change the mags to get this opposite to my other pickup?
At the moment they do not not cancel hum when used together. Thanks. Any advice would be great! - Rob

 

[Aceman]

Re: Is it possible to change a pups magnetic polarity?

Yes - just have superman fly around it faster than the speed of light. Not only will the polarity be reversed, but it will be taken back in time to a pooint where it is suddenly an aged vintage pup! :jester:

 

[rmcfee]

Re: Is it possible to change a pups magnetic polarity?

I like your thinking Aceman! It may be difficult to do however. - Rob

 

[tone4days]

Re: Is it possible to change a pups magnetic polarity?

have you tried flipping the pickup in question around, then wiring it reverse?

by 'flipping it around' i mean to say "so that the polepiece that use to be under the Low E string is now under the High E string, and vice versa ..."

by wiring it in reverse, i mean to say "so that the wire that use to be hot is now ground, and vice versa ... "

try that and let us know

t4d

 

[Artie]

Re: Is it possible to change a pups magnetic polarity?

have you tried flipping the pickup in question around, then wiring it reverse?

I'm not positive, but I don't think that will work. If the coil was wound clockwise, it will still be clockwise. Same for CCW. I believe a coil must be reverse-wound and reverse-polarity (RW/RP) to be humcancelling.

I think.

Artie

 

[tone4days]

Re: Is it possible to change a pups magnetic polarity?

yeah - you are right about RW/RP artie .. i am skeptical, but this was all i could come up with ... i was trying to visualize in my mind if flipping it then using start as finish and finish as start would get it done

still not clear in my mind the effect of the pole pieces themselves ... are they little bar magnets that would have to be inverted from "North facing outward" to "south facing outward"?

 

[JacksonMIA]

Re: Is it possible to change a pups magnetic polarity?

still not clear in my mind the effect of the pole pieces themselves ... are they little bar magnets that would have to be inverted from "North facing outward" to "south facing outward"?

On a single coil, yes. At least that's the way I understand it.



What about some sort of phase inverter? I know it would be like building a nail gun to drive a single nail, but would it work?

 

[STRATDELUXER97]

Re: Is it possible to change a pups magnetic polarity?

I had Seymour Duncan Company reverse the magnet polarity on an SSL6 so I could use it with a set of Fender Fat 50s several years ago...I sent the pickup to Scott Miller and he took care of it for me..

 

[Artie]

Re: Is it possible to change a pups magnetic polarity?

The pup in question has a bar magnet on the bottom attached with wax and the usual 6 rods (like any Strat pup).

If it has a bar magnet, the poles probably aren't mags. Can't you just pry it off gently, flip it like a humbucker mag, and re-attach it. You may need to hit it gently with a hair dryer to reflow the wax.

 

[octavedoctor]

Re: Is it possible to change a pups magnetic polarity?

You can do it with the alnico rods as well, but only on the ones with the moulded bobbins. You need to rest the bobbin on a block of wood with some holes drilled in it and gently push them out with a dowel.

Don't try it with a vulcanised fibre bobbin though; you'll stuff the coils.

Evan, if you read this, what did you say that vulcanised fibreboard they use for bobbins was called?

 

[Zhangliqun]

Re: Is it possible to change a pups magnetic polarity?

have you tried flipping the pickup in question around, then wiring it reverse?

by 'flipping it around' i mean to say "so that the polepiece that use to be under the Low E string is now under the High E string, and vice versa ..."

by wiring it in reverse, i mean to say "so that the wire that use to be hot is now ground, and vice versa ... "

try that and let us know

t4d

Changing a pickup's physical position won't have any effect on it's magnetic polarity. If you then reversed the leads, not only would the pickup be out of phase with other pickups, you would have more noise because the ground lead, which grounds the rod magnets, is now the hot lead.

To change polarity on Strat pickups, you would have to pull the rod magnets out and put them back in upside down, which is not a good idea because they would scrape against the coil and possibly cause a short.

Luckily on humbuckers it's real easy -- just pull the bar magnet out and flip it over.

 

[dr.barlo]

Re: Is it possible to change a pups magnetic polarity?

Buy another pickup if this is giving you real headaches. There is nothing you can do.

What you need is NOT reverse polarity. Forget it. What you need is a reverse wound (with respect to yours) single coil pickup. Then, even if the two pickups have the same polarity 60's hum would be eliminated when both are active. RWRP is the way fender did back in the way. But all you need is RW and not RP (because you can handle the RP with using the ground as the hot connection). Think of HB's, there the two bobins have to have the same polarity!

I think RWRP is rather a tradition thing, while RW is a necessity. (DiMarzio does not do RP at all as far as I have seen.)

B

 

[Artie]

Re: Is it possible to change a pups magnetic polarity?

Hey Doc; I don't think thats quite right either. I'm pretty sure that both RW and RP are required. The two coils of a humbucker do see opposite polarities of the magnet due to the way it lays underneath.

Here's how noise-cancelling works:

Both coils are wound opposite of each other. They both pick up noise out of the air in phase. You connect the two coils out-of-phase. Thus, the noise cancels. The strings, on the other hand, vibrate within opposite polarity magnet fields. They generate opposite polarity voltages. Since the two coils are connected OOP . . . the two signals add together to make the final signal.

Eliminate either the RW or the RP and the pup won't have much signal.

 

[dr.barlo]

Re: Is it possible to change a pups magnetic polarity?

Yep I was wrong, but you are wrong too. :beerchug: :burnout:

Check this out:

https://forum.seymourduncan.com/showthread.php?t=32899

You need reverse polarity but not reverse winding. Indeed you can correct the reverse winding by switching the hot and the ground. I should have remembered :smack: from the middle position on LPs! :smack:

Anyway that's it: RP needed but not RW. I did not remember entirely right. So gotta correct what I have written by reversing RW and RP! :laugh2: :burnout:

Best,

B

 

[Artie]

Re: Is it possible to change a pups magnetic polarity?

Now my head is spinning. But yeah, you're right. After I posted that I remembered that I disassembled a humbucker once, and tested the coils with an o'scope. They were wound the same direction.

Someday . . . this will all sink in.

Artie

 

[Aceman]

Re: Is it possible to change a pups magnetic polarity?

Swap wires will do the job. But the superman solution is way more fun...

 

[rmcfee]

Re: Is it possible to change a pups magnetic polarity?

OK ! I did the experiment and this is what happened:
It worked! No hum in the "in between " position with both pups on and the pups are IN electrical phase (in other words no thin tone -- beautiful Strat "out-of-phase" sound.)
I flipped the magnet over (after loosening the wax with my soldering iron) and then reversed the pup leads also ( black had been hot, is now ground).
Thanks so much to all for the advice! - Rob

 

[tone4days]

Re: Is it possible to change a pups magnetic polarity?

glad to have helped

i wasnt confident enough to stake my reputation on it , but i had a sense that both the flip and reverse wire would get it

if it had been a traditional single coil pup with rod magnets as poles (instaed of a bar magnet underneath), it wouldnt have worked for the reasons outlined above by others

enjoy
cheers
t4d

 

[octavedoctor]

Re: Is it possible to change a pups magnetic polarity?

You need reverse polarity but not reverse winding. Indeed you can correct the reverse winding by switching the hot and the ground. I should have remembered :smack: from the middle position on LPs! :smack:

That's quite correct, however if you are picky RW is preferred because if you just swap the signal and earth you get a change in the s/n ratio.

Some manufacturers prefer to take the signal wire from the blind (inner) end of the coil. This makes the outer windings connect directly to the earth circuit, effectively screening the inner coils. If you have screening tape on a pickup and the output wire comes from the outer windings then the screen will be proximal to the signal output, which will see a capacitance across the signal path knocking off some of the h/f component. Taking the signal from the inner coils avoids this, though at the expense of some inductive coupling which presents as a buzz when you touch a pole piece.

 

[Imp]

Re: Is it possible to change a pups magnetic polarity?

reading this, you've gotta appreciate how much further ahead of his time seth lover was

tom