Fuzzy bending, and not in a good way.

[nicholaspaul]

I built a humbucker as a kind of experiment. One coil has six neodymium pole pieces, like a single coil, and other has six screws and a neodymium bar magnet. Split, it sounds great. Not exactly '57 strat like, but rich and bell like nonetheless. I like it. Un split, it's a little quieter, but that's not my main concern at the moment. I'm just going to assume the magnet on the screw side is weaker resulting in the total being less than the sum of its parts.
The problem I'm having is that when I bend the low E and A strings, the sound goes fuzzy (think AM radio rather than Hendrix) and then dies, like the sustain has been cut off. The poles are 5mm wide and pretty powerful so it doesn't seem like an issue with bending the string out of the magnetic field. The other four strings are fine, as are the other pickups.
Before I rip this thing apart and start problem solving, can anyone point me in the right direction as to what on earth may be causing this?

[copperheadroads]

I'd say the strong Neo magnets are pulling the strings & possible interfering with the other coils field .
First thing I would do is adjust the humbucker quite far away from the strings & see if this helps .

[madzub]

when it's split, which coil are you using? have you tried each coil, and are they the same or different output?

the one with the screws should be higher output, as the screws give it inductance. The one with the neo poles will have very low inductance, as neodymium has almost no permeability.

Have you got the pole directions all properly aligned? All north up on one coil, and south up on the other?

[David Schwab]

I'd say the strong Neo magnets are pulling the strings & possible interfering with the other coils field .
First thing I would do is adjust the humbucker quite far away from the strings & see if this helps .

I agree here. I would not use neo magnets as pole pieces. But using them to charge steel pole screws is fine.

Also, are all the magnets oriented the right way? In other words, all facing the way way on the pole piece coil, and the opposite on the screw coil? Almost sounds like you are bending onto a different magnet polarity.

And when in humbucking mode, are the two coils connected electrically out-of-phase? Assuming they are both wound in the same direction, that should be start to start, or finish to finish. And north up magnets on one coil, and south up for the other.

If the two coils are wired in-phase, they will hum, and be out-of-phase to the strings, and sound thinner and weaker.

[Rick Turner]

That sounds like the neos may not all be pointing the right way. If you have something like NSNSNS, then when you bend a string, you're getting Barkhausen distortion as you move a string from one pole orientation to another.

[Mike Sulzer]

On the other hand, the permanent field might be higher at the strings over the coil using the individual neos. Not sure which will be stronger. Also, hum might not cancel so well with different inductances for the two coils.

(And I second DS's suggestion to check the polarity of the neos for consistency. Reversing the one under the A string, for example, could cause the type of loss of output when bending that np reports.)

when it's split, which coil are you using? have you tried each coil, and are they the same or different output?

the one with the screws should be higher output, as the screws give it inductance. The one with the neo poles will have very low inductance, as neodymium has almost no permeability.

Have you got the pole directions all properly aligned? All north up on one coil, and south up on the other?

[nicholaspaul]

I've had good results making single coils using neo rods so I figured they would work in a humbucker. The idea was to make a humbucker with a more single coil sound when split - I know, I'm not the first, probably something everyone wants, and all that, but it was worth a shot. As it happens, it does split well, with a marginal drop in volume. The humbucker sound isn't exactly a massive PAF type, but that's how I like it. I like upper frequencies (perhaps it's my age and subsequent loss of hearing... )

I fixed the fuzzy problem though. Those two magnets were indeed the wrong way around. Sloppy workmanship. Pfft. But I learned something today!

Big thanks Rick, David, Andrew and Mike.

So clearly others aren't keen on neodymiums..what kinds of success have you had, or was it just not worth the bother?

[David Schwab]

I've had good results making single coils using neo rods so I figured they would work in a humbucker. The idea was to make a humbucker with a more single coil sound when split - I know, I'm not the first, probably something everyone wants, and all that, but it was worth a shot. As it happens, it does split well, with a marginal drop in volume. The humbucker sound isn't exactly a massive PAF type, but that's how I like it. I like upper frequencies (perhaps it's my age and subsequent loss of hearing... )

Half a humbucker is not the same as a single coil. It can be done though.

I fixed the fuzzy problem though. Those two magnets were indeed the wrong way around. Sloppy workmanship. Pfft. But I learned something today!

Big thanks Rick, David, Andrew and Mike.

I thought that was what it was! I've had that happen myself.

So clearly others aren't keen on neodymiums..what kinds of success have you had, or was it just not worth the bother?

I use neos. I've been using them since about 2005. I like them. I'm just not so sure I'd use neo rods as poles, as they might be too strong. But it depends on the size of the magnets. Mike uses small neos in conjunction with ferrite rods.

[rjb]

Half a humbucker is not the same as a single coil. It can be done though.

Do you mean something like this (reputedly the first hum-canceling pickup on the market that sounds like a single coil)?
https://docs.google.com/viewer?url=p.../US3902394.pdf

[Rick Turner]

Oy vey! Not another old claim that this sounds just like that...which is built completely differently!

BTW, Willie Loretz Stich = Bill Lawrence. And to me, Bill's pickups sounded increasingly like the inverse of his hearing loss the older he got, God bless the man... I knew him, I respected him, but he was a piece of work. I was "the fly on the wall" once with Bill and Les Paul verbally duking it out re. who had done what first. It was hilarious.

[nicholaspaul]

Half a humbucker is not the same as a single coil. It can be done though.

Is that due to the poles not being the magnets or different magnets being used? Can a humbucker of sorts not be made with one half as a single coil, or even both, like the StagMag from Seymour Duncan?

I use neos. I've been using them since about 2005. I like them. I'm just not so sure I'd use neo rods as poles, as they might be too strong. But it depends on the size of the magnets. Mike uses small neos in conjunction with ferrite rods.

Do you find neos suit bass pickups more than guitar pups?

[Rick Turner]

The StagMag is a great pickup. I modify them for use with bronze wound string sets by drilling out the base plate holes under the B and E so I can push the magnets farther away from the strings to get better string to string balance.

[rjb]

Is that due to the poles not being the magnets or different magnets being used?

My guess is that David was referring to the shape of the magnetic field.
In humbuckers, some flux travels along the string between the rows of poles- whether or not one of the coils is cut.

I tried to elicit some elaboration on "It can be done though" by introducing the Bill Lawrence patent.
But so far, DS hasn't taken the bait.

RE BL's personality: I've never met him, but I have noticed a bit of braggadocio in his writing....
RE BL's patent: I took a double-take on reading this line...

Although it is not understood why this particular pickup construction works fantastically well,...

[big_teee]

Another issue with splitting humbuckers?
The common method is to just ground the finish lead.
That splits it, but the other coil is usually still tied to the circuit on one end.
IMO they never really sound like a single coil, split like that.
To prove that, when split, tap on the unused coil magnets with a steel device, and you still get some popping sound.
Less than the active coil, but still seems some sig is going to the supposed unused coil.
Maybe others can shed more light on better ways to split them.
T

[Rick Turner]

Try going "open circuit" with one coil instead of shorting it out and see what happens.

Also, you can bang on a supposedly dead humbucker coil without there being some kind of magnetic coupling from the core of the "deadened" coil to the other coil. You've got relative motion going on there.