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Parallel Versus Serial

Dugz Ink

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I'm trying to sort out everything that I'm reading, but there are a few things that still don't make sense. I'll start with what I think I know, then go on to what I know I don't know.

In a side-by-side humbucker pickup, there are two coils; one is North up and the other is South up. When you reverse the wires on the South up coil, this reverses the reverse phasing. When that is mixed with the signal from the North up (in phase) coil, it cancels any noise (plus minus mix) while adding the signal of both coils.

If you run your humbucker coils in parallel, then you should also cancel any noise that is picked up by the wires that are running to the control cavity. However, if you run the coils in series, I don't see how it could cancel that noise... so wouldn't parallel wiring be better for noise reduction?

I can see how serial versus parallel will affect total output, but not the noise cancellation properties of serial wiring. If you can help, I would appreciate it.


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Humbuckers are actually wired in series by default. Since the noise cancellation is only dependant on the polarity of the coils (not the magnets) then it really doesn't matter which way they are wired (series or parallel). It comes down to the coil winding direction. If they are the same you will get an increase in the noise signal; if they are wired opposite they will cancel out the noise signal. This has nothing to do with the coils being in phase (so switching the output and input wires won't affect it). It has to do with the direction of the windings. Think clockwise and counterclockwise and it may be more clear.

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It has to do with the direction of the windings. Think clockwise and counterclockwise and it may be more clear.

Hmmm... okay... but, on the assembly instructions for the Stew-Mac Humbucker Pickup Kit (Sheet i-5961) I read that...

6. Traditionally PAF wire is wound counterclockwise (looking at the face of the bobbin).

Then, in a series setup, by connecting the "start" wire for each coil to the switch/pot, and connecting the "finish" wires together, one coil is "in" phase while the other is 180° "out"... which creates the noise cancellation... but that would only produce sound if something else was inverting the signal that was generated by the strings moving over the magnetic field(s). That's why I though that the magnetic polarity was changing the phasing, not the direction of the coil winding.

EDIT: Here's something that supports my conclusion, from the same instructions...

13. With the hookup wire running flush along the baseplate fence, place the metal spacer and magnet on the baseplate (south polarity facing the metal spacer). Locate the slug coil (north polarity) on top of the magnet and...

I'm still confused, but at least I don't feel like I'm losing my mind.

Well... at least not when it comes to magnetic polarity, but...


Edited by Dugz Ink
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And now I see part of the source of confusion... in one of the first links that was posted...

In a humbucking pickup, the two coils are wound with opposing electrical polarity, but the magnetic polarity for each coil is also reversed. (snipped) The polarity of the desired signal is dependent on both the polarity of the magnet and the direction of the coil winding so this signal is "in-phase" across the two coils. The polarity of the noise signal is independent of the magnets -- it depends only on the direction of the coil winding -- so the noise signal across the two coils is cancelling, or out-of-phase.

That would be like taking a pickup coil, flipping it over, and mounting it face down. And since the winding and magnetic polarity are both reversed... the wire re-reverses the phasing if the pickup so that only the wiring is "out" of phase... but I'm still confused because that isn't what Stew-Mac's site describes.

Also, I would think that wiring finish-to-finish would make a huge difference, depending on whether the coils were wound the same direction or opposite directions, because that directly affects polarity.

Maybe I shoud just make wooden flutes.... (SFSF)


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  • 3 weeks later...

Since I didn't get any more responses, I decided to experiment with my humbuckers.

With my first project guitar near completion, I hooked up the humbuckers (each has 4 iwres, plus woven shielding around them) to a connnection strip, and then used the strip like a patchbay. My shop has several florescent lights over the work benches, and I did not hook the shielding to a ground, so I got a ton of buzz... but that was a good thing.

Hooking up one half of one humbucker was noisy and weak, of course.

Hooking up both coils (on either humbucker) in series reduced the noise and greatly enhanced the sound.

Hooking up both coils (on either humbucker) in parallel reduced the noise more, but it also lost some of the punch and levels in the sound. Turning up the amp until this wiring sounded as loud as the "in series" wiring still seemed to produce a little less buzz, but not enough of a difference to justify the loss of presence in the audio.

I know, there are a lot of sites that say "wire them in series"... but I want to learn "why"... instead of just following what everybody else is doing.


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