Pickup Magnet "slug" Direction

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Nudger
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Pickup Magnet "slug" Direction

Post by Nudger » Sat Jun 05, 2021 8:02 am

Im in the middle of building a stereo Marauder..

Ive got two split XII style pickups.
All four halves are wound in the same direction.

Thing is !??!

The bridge pickup magnets are north
The neck pickup magnets are south

Would this be a problem?

Just scribbled a quick (basic) diagram...
Image

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adamrobertt
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Re: Pickup Magnet "slug" Direction

Post by adamrobertt » Sat Jun 05, 2021 9:42 am

They will be in phase in the middle position but they will not be hum-canceling. You need to have them with reverse polarity AND reverse wound to also get the hum-cancelling effect. They will still work, though.

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Re: Pickup Magnet "slug" Direction

Post by Nudger » Sat Jun 05, 2021 10:52 am

Thanks thats good to know..I wasnt bothered about hum cancelling.

I specified that I wanted non hum cancelling for this build as I wanted all pups wound in same direction.

More worried about phase problems with the multiple half pickup combinations. With each half having on/off.

For some reason the bridge and neck pups magnets are in opposite directions so thats where I was stumped.

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Embenny
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Re: Pickup Magnet "slug" Direction

Post by Embenny » Sat Jun 05, 2021 4:16 pm

If a single coil pickup is out of phase with anything, you just flip the leads. The magnet direction will simply determine whether the in-phase tone happens to be humcanceling or not. It's impossible for you to end up in a situation where you can't get these pickups all in phase with each other.
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Re: Pickup Magnet "slug" Direction

Post by timtam » Sat Jun 05, 2021 8:58 pm

If the 'up' magnetic polarities are opposite (as yours are), then the "in-phase" (same electrical polarity) combination of the coil wires will create a RWRP pair in the middle position. That is, the in-phase combination will always be hum-cancelling. If you flip the coil wires on one pickup then the pair would be out of phase with no hum cancelling. So with opposite magnetic polarities, your only real option is RWRP (ie hum-cancelling) in the middle position. Most people would probably regard that as "good". ;)

You can determine if the electrical polarity a pickup (magnetic polarity plus wind direction) is positive or negative with the "screwdriver" test, using current, voltage, or resistance deflections (those different approaches at the links below - the ammeter is the clearest). If both pickups have the same electrical polarity (both negative or both positive), they will be "in phase". That saves having to wire them up and listen to the pair to figure out if you have the hot and ground wires the right way round to be in-phase.
https://www.premierguitar.com/mod-garag ... ter-part-1
https://www.mojotone.com/support/knowle ... f-A-Pickup
https://www.youtube.com/watch?v=2lFQzmRvePc
https://youtu.be/7UfxQBhqen8?t=1122
"I just knew I wanted to make a sound that was the complete opposite of a Les Paul, and that’s pretty much a Jaguar." Rowland S. Howard.

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Re: Pickup Magnet "slug" Direction

Post by Nudger » Sat Jun 05, 2021 10:44 pm

mbene085 wrote:
Sat Jun 05, 2021 4:16 pm
If a single coil pickup is out of phase with anything, you just flip the leads. The magnet direction will simply determine whether the in-phase tone happens to be humcanceling or not. It's impossible for you to end up in a situation where you can't get these pickups all in phase with each other.
Thanks, I can now finish the wiring with the confidence that I wont have to start again from scratch.

I had the pickups hand wound by Alegree UK but forgot to specify "Non" RWRP ::)
Im guessing the bobbins had been made before I got back to him to correct my specs.

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Re: Pickup Magnet "slug" Direction

Post by Embenny » Sun Jun 06, 2021 11:05 am

Why did you want them to be all the same magnet polarity? All that flipping the magnets in this manner does is ensure that if you activate a neck and bridge coil together, they will cancel hum.

Personally, when I built my Jaguar with XII pickups, I asked for each pair (bridge, neck) to be RW/RP like a P-bass pickup, so that any combination of bass coil and treble coil would cancel hum.
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Re: Pickup Magnet "slug" Direction

Post by Nudger » Sun Jun 06, 2021 1:07 pm

Simplicity "lack of knowledge" :D
Wanted each half to be identical like four separate Single coils.
This is basically two Tele circuits converging on a switch to give stereo or mono...
Treble halves one circuit bass halves the other, Something ive not tried before.
With each half "pickup" having an on/off switch I wanted to be sure that whatever combination they would all be in phase.
When they arrived With different magnet directions it just threw me..

I personally dont worry about hum and have even given up shielding my builds..

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