Help with weird humbucker!

[888guitars]

I have listed the colors of the wires. How would you wire this?? It’s a humbucker with a coil under the slug side. I’ve never seen one!?!

[bbsailor]

I have listed the colors of the wires. How would you wire this?? It’s a humbucker with a coil under the slug side. I’ve never seen one!?!

This is the first time I have seen this style pickup. What I am going to say is just how I would approach wiring this pickup to extract the most tonal variations.

1. Wire the two upper coils as a typical humbucker with the coils in series.

2. Wire the two stacked coils as a single tall coil like pickup. Wire it with the upper and lower coil in series and then reverse the phase of the lower coil and listen for tonal change or noise reduction when the lower coil is out of phase with the upper coil.

3. Switching between these two configurations cold be done by shorting out the unstacked coil and unshorting out the lower stacked coil.

You may even get a third effect by using it in a normal humbucker mode but with both the upper and lower coils working as half the humbucker mode.

Wire them up manually to listen for the pickup tone differences as well as the noise differences when the stacked pair is used either in phase or out of phase with each other.

Once you identify the combination you like, then you can figure out how to use common SPDT or DPDT switches to get the two or three sound combinations you seek.

This is just my best guess!

Joseph J. Rogowski

[888guitars]

I’m assuming that when the humbucker is tapped, the single coil tone is now “noiseless” using the coil underneath?

[bbsailor]

I’m assuming that when the humbucker is tapped, the single coil tone is now “noiseless” using the coil underneath?

That is a good assumption. Do this test to listen for how much string induced signal is going into the lower coil. Just attach the lower coil to an amp input and listen for any signal. If little to no signal this there, then the lower coil is designed for humbucking noise reduction.

Let us know how you wire this unusual pickup.

Joseph J. Rogowski

[Chuck H]

That looks to be a dedicated magnet for the screw side coil left. If the slugs go all the way through BOTH coils on the right I would think that the two right coils are intended to be wired in series/phase as a dedicated single coil. If the slugs do not go through the lower right coil it's probably intended to be wired like a noiseless single coil.

I actually like the tone of asymmetrical humbucker coils. Even though it IS less humbucking. So if the slugs DO go through both right coils you could also try the pickup wired as a humbucker with a "tap" for the slug coil side. Like bbsailor's "third effect" above.

But I think it may be telling as to whether the slug side magnets go through both coils is my point.

[Helmholtz]

. If the slugs do not go through the lower right coil it's probably intended to be wired like a noiseless single coil.

A "noiseless single coil" would actually be a (stacked) humbucker as opposed to a side-by-side humbucker.

[John_H]

How would you wire this?? It’s a humbucker with a coil under the slug side. I’ve never seen one!?!

As others have stated, the first two obvious options is that it can be wired as either a HB, or a noiseless type single coil. What are the measurements of the 3 coils. DC resistance, and inductance?

[Chuck H]

A "noiseless single coil" would actually be a (stacked) humbucker as opposed to side-by-side humbucker.

Ah. Ok. But doesn't a humbucker have the windings in series out of phase and opposing magnetic polarities? I guess it's not clear to me how to get that with magnetic slugs through stacked coils.

[Helmholtz]

Ah. Ok. But doesn't a humbucker have the windings in series out of phase and opposing magnetic polarities? I guess it's not clear to me how to get that with magnetic slugs through stacked coils.

To me humbucking means the principle of using 2 coils wired for hum compensation (either series or parallel wiring).
With a side-by-side humbucker both coils can be used to pick up a string signal.
With a stacked humbucker only the upper coil receives a string signal while the lower one is just a "dummy coil".
Any residual string signal picked up by the lower coil will reduce output.

I dunno how the PU here is meant to be used/wired, but following bbsailor's advice might give some clue.
Not sure if the coil arrangement makes much sense.

[Chuck H]

To me humbucking means the principle of using 2 coils wired for hum compensation (either series or parallel wiring).
With a side-by-side humbucker both coils can be used to pick up a string signal.
With a stacked humbucker only the upper coil receives a string signal while the lower one is just a "dummy coil".
Any residual string signal picked up by the lower coil will reduce output.

I dunno how the PU here is meant to be used/wired, but following bbsailor's advice might give some clue.
Not sure if the coil arrangement makes much sense.

Thank you. I just did some research and got some clarity. It's definitely an imperfect device (stacked humbuckers). I wonder then if having pole slugs in only the upper coil wouldn't be better. Unless the actual inductance of the coil is critical to hum cancellation? I didn't think it was.

[Helmholtz]

Slugs extending into the lower coil would produce some unwanted string signal.
No slugs in the lower coil probably requires using more turns for good hum cancellation.

It's not directly related to inductance, but a ferrous core increases the number of hum fieldlines passing the coil.

[Chuck H]

Slugs extending into the lower coil would produce some unwanted string signal.
No slugs in the lower coil probably requires using more turns for good hum cancellation.

Well I'm it's probably been tried considering how many people innovate in the pickup genre. If there were merit to the idea someone would be making them that way. Thanks for the clarity.

[Chuck H]

FWIW Fenders current stacked humbucker designs use a metal plate between the coils. I expect this would do two good things. It would offer some directional shielding to the lower coil and probably make the upper coil and lower coil tend more towards the magnet polarity at either end of the slugs. Both would seem to make the design more efficient.

[bbsailor]

Slugs extending into the lower coil would produce some unwanted string signal.
No slugs in the lower coil probably requires using more turns for good hum cancellation.

Helmholtz,

The uncertainty of the slugs going through the lower coil was the reason why I suggested to listen for the signal level of the lower coil alone. Little to no signal could indicate that the purpose of the coil is noise reduction.

If you were to place a hand held magnet under the lower metal plate, assuming it is not magnetic, and attempt to feel some attraction under the lower coil would indicate that the slugs were going through the lower coil.

My best guess is that it works in humbucking or noise reduction in both the traditional humbucking way and the single coil stacked noise reduction way.

Joseph J. Rogowski

[Helmholtz]

FWIW Fenders current stacked humbucker designs use a metal plate between the coils. I expect this would do two good things. It would offer some directional shielding to the lower coil and probably make the upper coil and lower coil tend more towards the magnet polarity at either end of the slugs. Both would seem to make the design more efficient.

Right, and Alnico poles are poor magnetic AC field "conductors".
So little of the string field can enter the lower coil.