Pickup Winding Questions...

[thegarehanman]

I'm winding some p90's for a guitar I'm building and for a friend. In an attempt to make something I can be proud of, I'd like to attempt to make these a sort of humbucking p90. All of the p90's that are humbucking that I can locate seem to have stacked coils. Now, does this mean that on one pickups, the two coils would have polarities that look like NSSN or SNNS?

Anyhow, I'm wondering if it would be feasible to wind the pickup as though it were going to have one coil, except to about half the resistance, then stop winding, tape down the current coil, so that it won't shift, then wind the rest of the pickup in reverse. This would mean that one coil would be in the center of the pickup and another coil, with an opposing polarity, would surround the inner coil. It seems to me like there shouldn't be anything wrong with this setup, especially considering the way magnets are arranged under a p90. Then again, I'm a mechanical engineering major, not an electrical engineering major. That said, can anyone see any potential problems with this design?

peace,

russ

[crafty]

Problem is you'll just be making a big transformer and you'll probably get little usable sound and almost no noise-cancelling at all out of it. Bad idea unless you can figure out a way to reverse the polarity on one of the coils, which is pretty much impossible in this application.

Edited October 24, 2006 by crafty

[GuitarGuy]

My only reservation on that one is that the output of a coil is relative to its proximity to the magnet/slug. In that scenario the 2nd coil would be larger than the first and because of its distance from the center not react the same as the inner coil.

My thoughts are that you would have some hum cancellation but not like a humbucker. But then again I've never tried it. I say give it a whirl, the results may be cool.

[thegarehanman]

crafty, the polarity would not be the same because the windings would be reversed on the outer coils.

Winding to specific resistances is a non-issue as I regularly check my resistance as I wind by exposing some wire, using a multi-meter, then coating the exposed area with some vinyl sealer.

Can anyone confirm that humbucking p90's simply have one coil stacked on top of the other with opposing polarities and that there are no other physical differences?

peace,

russ

[Phil Mailloux]

My only reservation on that one is that the output of a coil is relative to its proximity to the magnet/slug. In that scenario the 2nd coil would be larger than the first and because of its distance from the center not react the same as the inner coil.

That's exactly what I was thinking. To top it off too, you would end up with a lot more wire in the outer coil than the first one thus making the output of the second coil higher than the first. Unless of course that you wind it to resistance instead of turns count.

Like guitarguy said, try it and we'll all learn from your experiments

[thegarehanman]

Like I said, phil, I wind to resistance, not coil count. Since I'll be wax potting these, it won't be a big deal if they have to come appart to be reconfigured.

[Mr Alex]

I tried your idea of reversing half way through. Measuring resistance and all that. It works. But I thought it sounded like rectum juice.

Every humbucking p90 I've seen is stacked coils, except one, it had a small coil either side of the pole pieces(they were dummy polepieces).

Hope that helps.

Alex

Edit : I should also point out, hum cancelling p90s don't sound "right".

Edited October 24, 2006 by Mr Alex

[crafty]

crafty, the polarity would not be the same because the windings would be reversed on the outer coils.

russ,

You're forgetting that pickups are an AC device, not a DC device. I don't think that it's going to work very well because of the transformer effect of having one coil wrapped around the other coil. The polarity may be reversed, but I don't think it's going to be 180 degrees out-of-phase electrically.

[marksound]

Hey Russ, check this out: http://curtisnovak.com/pickups/tel-hc.shtml

No idea what it sounds like, but it's an idea ...

[thegarehanman]

Thanks guy, and thanks for the link, marksound. I actually have been toying with that idea. It certainly should preserve the tone associated with the p90. The only problem there would be the fact that I have this setup with two polepieces for each string. That might make for a tight size constraint between the D and G polepieces. Once I have a few new bobbins put together, I'll start winding and see where it leads.

peace,

russ

[Phil Mailloux]

The Curtis Novak design wouldn't work in this case because P90 pickups are very thin, making the coil quite large. If you were to build something like that it would look more like a Precision bass pickup. They wouldn't fit next to each other.

I've got a feeling you already know that Russ, right?

[unklmickey]

one possibility would be to use stacked coils.

the first coil would be just like a standard P-90.

the bottom coil would be mounted UNDER the baseplate, connected in series, out of phase with the normal coil.

since a p-90 is pretty shallow to start with, the rout probably wouldn't need to be any deeper than a standard HB.

oh BTW, in your idea about reversing the winding halfway through....

since the windings would be reversed, but the magnetic polarity is the same, you would get effective hum-canceling.............and equally effective signal canceling.

Edited October 25, 2006 by unklmickey

[thegarehanman]

The Curtis Novak design wouldn't work in this case because P90 pickups are very thin, making the coil quite large. If you were to build something like that it would look more like a Precision bass pickup. They wouldn't fit next to each other.

I've got a feeling you already know that Russ, right?

Yes phil, I'm well aware of that. I'm going slightly taller and narrower than a traditional p90 though, for a bit more clarity at the cost of some growl. So in that respect, it could still be possible, but the pole piece issue rules that out anyhow. It's all a learning experience. Pickups are a whole different animal than the woodworking aspect of this hobby, and I'm just getting started.

Edited October 25, 2006 by thegarehanman

[psw]

Hey there...some interesting ideas here...maybe this tread could grow like mine...

Speaking of which, there have been some similar questions and solutions posed from time to time on the sustainer thread as well as innovative ways of making coils. The sustainer driver is afterall, very much a pickup in reverse but suffers from emiting interferance (EMI), not attracting it!

Off topic, here is the latest coil made from a very simple jig...

Back on topic...

oh BTW, in your idea about reversing the winding halfway through....

since the windings would be reversed, but the magnetic polarity is the same, you would get effective hum-canceling.............and equally effective signal canceling.

So, no...this is not going to work for you...no hum but no sound!!!

The bi-lateral idea is neat...think the P-bass or Fender/G&L Z-coils too. I am surprised that Novak was able to fit them end to end like that without there having to be some overlap.

The stacked coil is just that with a magnet that is north on the top, south on the bottom and so making a humbucking effect given their placement on the magnet as mirror images of one another. If you wanted to make a more P-90 type configuration, you could put thin magnets to nuts that hold the screw poles with a coil on top and bottom in a kind of sandwich between the coils.

Part of the sound of the p-90 is the wide magnetic field and wide thin coil design...

Edit : I should also point out, hum cancelling p90s don't sound "right".

Yes...well, so far. They will perhaps sound different, they won't be p-90's but what is right?

If you ignore the hyperbole of Kinman, there are a few interesting approaches he has taken. Now many say that his pickups do sound convincingly right. Certainly for a stacked pickup, he has got some of the main elements of the "sound" right. One aspect is the use of a magnet in the top coil and steel slugs, magnetised by the above coil, for the second coil. Similar is the approach of Fender's noiseless and a few others both past and present...novel ideas can be gained from patent searches of kinman, lace, lawrence, fender, gibson and others...

There is room in the p-90 format for a lot of interesting humcancelling propositions many of them that mirror the desired sound that a traditional pickup can produce. As long as you are content to experiment, you may find yourself with an entirely different animal that has it's own growl that may appeal just as well.

Interestingly, with pickups, it is often the inconsistancies that produce the most desired results (scatter winding for instance) and a home made pickup may produce a superb result...

In the P-90 format, I'd like to see two bi-lateral coils that slightly overlap with screw poles off-centred (so would need to make own covers I guess) and thin coils and dual magnet wide fields. A similar approach would be a thin rail like pickup but with poles only for each coils under the lower and higher strings, half of the coils, though spanning the whole string set, only producing some output.

These kinds of strategies have been explored lately in the sustainer thread as I have said with a number of configurations for both the driver, and for the pickup that exists below them.

For those not wanting to do a full on custom winding and bobbin constructing, and don't mind a bit of extra depth...you could take apart a cheap rail driver, pot it and spread the rails apart a little more and incorporate two magnets to the outsides of the "blades" (or substitue screw poles) to mimic the wider magnetic field certainly could add something different, even if it weren't a P-90, it could provide something of the flavour you are looking for...

Just a thought...will be interesting to see what you come up with... pete

[Robert_the_damned]

Lace are even kind enough to furnish you with a nice diagram of what exactly the inside of their pickups looks like:

they even explain how they work on their site!

[unklmickey]

Hey there...some interesting ideas here...maybe this tread could grow like mine...

grow, yes.

like yours? yikes!....another thread that needs it's own zip-code? scary thought, that.

Robert,

that drawing resembles the innards of the 'Sidewinder' bass pickup, used in the neck position, on Gibson EB0s and EB3s.