[QUESTION] Review wiring / humbucker wiring clarifications?
So I'm trying to replace the humbuckers on my HSH guitar with another set, because I didn't really like the neck humbucker and it was also not coil-splittable. The bridge humbucker is currently coil-splittable via push-pull pot and is noise cancelling in the 4 position with the middle single coil. A slight complication here is the fact that both of those humbuckers are the "no polepieces" types, as in they look like active EMG pickups, but they're normal passive ones - so without the polepieces accessible, I'm not 100% sure which coil of the bridge humbucker is actually used when split - the voltage measurements seem to suggest it's the North coil, as I would assume it should be for noise-canceling to work with the middle South single coil, but I'm not 100% certain.
I got a set of two humbuckers (dedicated bridge and neck) that supposedly use the Seymour Duncan color code. I would really love to get the wiring correct the first time if possible, not mess around with out of phase pickup combinations for hours, so using the multimeter (and the pull method) and compass, I've came up with this kind of wiring to make both of the humbuckers coil splittable and noise cancelling in both the 2 and 4 position when coil split:
https://photos.smugmug.com/photos/i-CmRv2NH/0/9cd68b13/O/i-CmRv2NH.png
This wiring seems to give me the same polarity of the output signal when measured with the multimeter on all individual coils and pickup combinations. So I would assume it's correct. The wiring of the bridge pickup is also how both of the pickups came pre-wired. The faint grounding on the connection between the two coils of each pickup is supposed to show how the coil split will be done. The plus sign shows the wire that is identified as positive when doing the multimeter pull test (as in that's the wire that shows positive values on multimeter if connected to the red probe and while putting a metal object to the polepieces, negative when pulling it away).
What I'm wondering, though, is if it *is* indeed correct, because there seems to be a lot of contradicting information about how to wire the coils. I've seen people explain that you should identify your positive wire on both coils, and then connect the coils by connecting + and + (or - and -) together, while using the other pair as your ground and signal. I've also seen people explain that you should use say - on the first coil as ground, connect + on the first coil to the - on the second one, and then use + on the second one as your signal. Some wiring diagrams seem to also identify the wires as "coil start" and "coil finish", and here once again I've seen both versions of the wiring (analogical to the + and - versions). All of those are supposed to be for the standard noise-cancelling humbucker series wiring. Though I'm not even sure if the + and - thing is indeed just a different way to say "coil start" and "coil finish"...
So I'm a bit lost as to what is actually correct. Both of those wiring options can't be correct. As mentioned, the pickups I got are supposed to follow Seymour Duncan color code, and come pre-wired like this, but if you're really supposed to wire + and + or - and - together like many seem to suggest, then they're pre-wired wrong...?
Add to it the magnetic polarity thing, and it all becomes clear as mud, really.
So I would really appreciate if someone could take a look at the wiring I came up with if it checks out, and if they could clarify what's the deal with the coil finish and start and + and - wiring. Are quite a few people on the internet actually wrong about the correct wiring? (I know, what an outlandish concept... ;) )
Thank you and sorry for the lengthy post, I wanted to explain it as accurately as I could.
Posted Apr 21, 2021, 11:28 PM UTC
“+”/“start” and “-“/“finish” are different names for the same thing, both indicating the winding direction. Winding is half the equation when it comes to noise cancellation - the other is polarity (but changing that takes a lot more effort).
For a conventional humbucker, you would wire the two “finish” wires or the two “start” wires together, as you want the two coils connected in series while being wound in opposite directions. Which one is which way only matters if you’re also trying to maintain noise cancellation with a single coil pickup.
As for your pre-wired pickups, they do follow the SD color code, you just have it labeled wrong. N+ is black, N- is white, S- is red, S+ is green. They’ve connected “finish” taps together to make a conventional humbucker.
I’ll need to look at your overall diagram again in the morning, as it’s late here, but I should be able to help you.
I haven't labeled it wrong. That's what I've measured using a compass and using the multimeter method to identify the positive wire of each coil. Maybe the wiring is wrong, but the labeling absolutely isn't. I've verified it several times over, because I was trying to understand it.
Bear in mind that only the bridge pickup matches the original wiring in my image, the neck pickup is rewired analogically to give me north coil on split, as the original wiring would've given me south instead.
And if start is the same as + and finish is the same as -, then I really don't understand why for example this guy in this video shows how to identify the wires:
https://www.youtube.com/watch?v=7UfxQBhqen8&t=1120s (timecode 18:40 and forward)
Which is exactly what I've done and that's how I identified the positive wires on each coil.
But in a following video, he talks about connecting the pickup itself and shows an example with a DiMarzio pickup, where he talks about how with DiMarzio pickups, green is negative from one coil with white being the positive from the same coil, and for the second coil, black is negative and red is positive, and literally says you should wire it "minus, plus, minus, plus to keep them in phase and how you would typically install them" (timecode 4:30 ish):
https://www.youtube.com/watch?v=bTKuqT1OkxI&t=270s
And yet, if you look at DiMarzio color codes and wiring, you usually get this:
https://cdn3.bigcommerce.com/s-fxdzp2uudp/product_images/uploaded_images/dimarzio.jpg
So the options are that the guy who just showed (correctly) how to identify positive and negative ends of the coil in one video doesn't know how to wire the pickups correctly in the next video, or that the DiMarzio color codes on the pictures are labeled wrong, or that + and "start" are not the same thing.
And this is just one example of many I've seen where this contradiction seems to emerge.
Mind you my current humbucker's wiring measures exactly like the one I'm about to install, and in accordance what the guy says in the video (so it's wired -, +, -, +), and it's in phase, definitely in series and also coil taps correctly with noise cancelling with my middle pickup). So... ¯\_(ツ)_/¯
(But thank you for responding, in any case, it's appreciated, even if it might not perhaps seem like it from what I just wrote :) )
After watching the video, I see the problem. The problem is an overlap in terminology/notation.
That video is applying principles of electromagnetics to guitar pickups. While this obviously works, guitarists and guitar techs are rarely electrical engineers. He's talking about +/- in terms of electromagnetics. In his case, "+/-" is inherently different from "start/finish", but pickup manufacturers (and subsequently guitarists) will use them interchangeably to mean the same thing in my experience. From that perspective, you have labeled them wrong, but not for the method of identifying which coil is which.
When you wire a humbucker, the two coils are reverse-wound and reverse-polarity from one another. You also see this when dealing with single coils connected in series like in a Strat - the middle pickup is often RWRP from the other two so that it cancels hum in the series (2 and 4) positions.
Reversing the polarity on a magnetic field affecting a coil of wire obviously has the effect of reversing the direction of current flow (electrical + and -). Reversing the winding direction is functionally the same as reversing the direction of current flow as well, so what you get is two coils that are electrically +/-/+/- wired in series (as makes sense), but with opposing magnetic polarities. Which means that common noise is phase-cancelled as it only receives one of the two flips, being external to the magnetic field of the pickup. There's actually a good series of articles about it on Seymour Duncan's blog.
Edit: with all that being said, having successfully overcome the notation discrepancies, and seeing that your coil splits* work the way you want with your middle pickup (which would be the only potentially tricky part of your wiring diagram, for reasons we don't need to get into) I can clearly see that your wiring diagram works.
*They are "coil splits" not "coil taps". A coil tap is actually something else entirely. Guitarists have an apparent passion for taking a term that means one thing and applying it to something related but wholly distinct. They did it with tremolo/vibrato (switching the terms from their original meanings) as well. /rant