Magnetic Polarity of SD Pickups

[Phostenix]

Everything I've read on the internets said that Seymour Duncan pickups are typically configured this way:

Black & White wires are the slug/inside coil with North magnetic polarity.
Red & Green wires are the screw/outside coil with South magnetic polarity.

I just bought a couple of SD pups off ebay from 2 different sellers - a Jazz neck & a JB bridge. That should be about as typical as it gets from SD, but on both of these pups, the inside coils are South magnetic polarity & the outsides are North.

I've confirmed that Black & White are the slug/inside coils and Red & Green are the screw/outside coils and that the electrical polarity is correct. One is new in box, the other used. Neither shows any sign of having been disassembled to have the magnet reversed.

Here's a picture of my compass & the red tip IS pointing to true (earth) north.

Here's the slug coil of the Jazz neck (NIB):

Here's the screw coil of the Jazz neck:

Here's the slug coil of the JB bridge:

Here's the screw coil of the JB bridge:

Am I doing this wrong or have I just been confused all along about the magnetic polarities of SD pups?

 

[Funkfingers]

Re: Magnetic Polarity of SD Pickups

Yes. You have been confused. Output conductor wires have no polarity.

On circuits were spilt coil combinations of coils are required with noise-cancellation, one of the magnets needs to be inverted (e.g. PRS Custom with rotary PU selector.)

 

[Phostenix]

Re: Magnetic Polarity of SD Pickups

Output conductors actually do have a polarity, in the sense of getting a positive voltage from a particular coil due to ferrous metal passing through the magnetic field vs. getting a negative voltage from the coil. With SD pups, the Green wire is - and the Red wire is + of the one coil. On the other coil, the White wire is - and the Black wire is +. In order for the coils to stay in electrical phase, you have to connect them - to +, - to + (the standard Green to ground, Red to White, Black to hot output). This electrical wire polarity also comes very much into play when you start connecting split coils together.

Yes, I also understand that if you want hum cancelling with split coil combinations, you need to have a North coil & a South coil together. That's why I'm determining the magnetic polarities.

What I'm wanting to know is if Seymour Duncan pickups (other than P-Rails, which I know are different) consistantly have the inside/slug coils as South magnets & the outside/screw coils as North magnets. Everything I've read in the past stated the opposite.

 

[drdave]

Re: Magnetic Polarity of SD Pickups

Your pictures aren't showing up for me. But the "N" on your compass should be attracted to the South coil on the pickup. Is that what you're seeing?

 

[Phostenix]

Re: Magnetic Polarity of SD Pickups

Your pictures aren't showing up for me. But the "N" on your compass should be attracted to the South coil on the pickup. Is that what you're seeing?

That's exactly what's happening. That's where I'm getting confused, thinking North on the compass will point to the North coil. Makes perfect sense that the North tip of the compass needle would be attracted to a South magnet, now that I think about it.

Thanks!!

 

[Phostenix]

Re: Magnetic Polarity of SD Pickups

I'll attach the pics in case there are others who can't see them.

They are in this order:

Jazz Slug
Jazz Screw
JB Slug
JB Screw

 

[sssteeve]

Re: Magnetic Polarity of SD Pickups

I had always assumed that the N needle of a compass would point to the S coil of a HB but I eventually earned that my reasoning was wrong:

Originally, the end of a magnet that pointed approximately North was termed its 'North-seeking' pole, and its opposite end was termed its 'South-seeking' pole. Over time, we have dropped the 'seeking' part of these terms, and the ends are now simply called their 'north' and 'south' poles, respectively. These names now represent the magnetic polarities of these ends. Since 'unlike poles attract', the magnetic polarity of 'Magnetic North' (the location) must be south.

http://wiki.answers.com/Q/What_is_magnetic_polarity_of_the_geographic_North_Pole_of_the_Earth

A compass will tell you if two pickup coils have the same magnetic polarity or not, which is what really matters if you are dealing with pickups on hand. However if you are going to order them you do want to consider that the N needle point will point to a coil with the N pole on top.

This chart from SD shows the wiring and polarity for some of the different brands of pickups:

http://www.seymourduncan.com/support/schematics/schematics.php?schematic=color_codes

HTH