2 types of wire in a HB?

[voodoochild]

[QUOTE=

There is a lot of variation in copper diameter from spool to spool, and formvar generally tends to be thicker than plain enamel.

[/QUOTE]

Yes this is very true. You can only argue there is no difference between insulations when in fact both spools are identical in copper diameter and insulation thickness. Otherwise you are barking up the wrong tree.

[Possum]

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Well if you want to get really nit picky no two spools of wire are identical in any way. I'm talking same build, same O.D., I hear a noticeable difference between formvar and plain enamel. My ears, my experience. If you want to tame some treble in a humbucker use single build formvar instead of PE. thats why I don't use it, especially noticeable in a neck position.

I don't know how you would even get an accurate measurement of bare wire and insulation thickness without getting some kind of lab equipment. You're talking .00001" differences when you get to insulations, hand held micrometers get real innaccurate at that tiny of a measurement, then there is the problem of how you remove the insulation without taking any of the copper with it? No one has answered that question on this forum so far. So you'd need to contact a lab and probably have a laser device do measurements, maybe a magnet wire manufacturer would be the only place that would know how to do this kind of work. AT a pickup maker's level all one can do is get a vague idea by how easy it is to scrape the wire off, it becomes obvious which wire has a thicker insulation etc. and you just use your ears on the particular wire you're working with.

[Joe Gwinn]

Well if you want to get really nit picky no two spools of wire are identical in any way. I'm talking same build, same O.D., I hear a noticeable difference between formvar and plain enamel. My ears, my experience. If you want to tame some treble in a humbucker use single build formvar instead of PE. that's why I don't use it, especially noticeable in a neck position.

I don't doubt that you hear it. The question is what are you hearing.

I don't know how you would even get an accurate measurement of bare wire and insulation thickness without getting some kind of lab equipment. You're talking .000,01" differences when you get to insulations, hand held micrometers get real inaccurate at that tiny of a measurement,

You can do 0.000,1" ("tenths") by hand, with care, Wire folk don't try to measure any closer.

then there is the problem of how you remove the insulation without taking any of the copper with it? No one has answered that question on this forum so far.

Sure we have. Use methylene-chloride based paint stripper. Or, heat.

So you'd need to contact a lab and probably have a laser device do measurements, maybe a magnet wire manufacturer would be the only place that would know how to do this kind of work. At a pickup maker's level all one can do is get a vague idea by how easy it is to scrape the wire off, it becomes obvious which wire has a thicker insulation etc. and you just use your ears on the particular wire you're working with.

Overkill. Just mike the insulated wire, strip the insulation off by fire or chemical, and measure again, all with a micrometer calibrated to tenths.

[Possum]

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Well, I am going by actual experience from alot of prototyping, rewinding the same pickup structure with different wire, same number of winds, same winds per layer. I just will not use single build formvar in a humbucker, it sounds good but lacks enough treble bite that plain enamel of the same diameter has. It might be good in a bridge pickup but its a better idea to use the same wire in both pickups, if you make minor changes in one pickup, changes you can't even hear, you will hear it in the middle switch position. Using a dark wire type in the bridge will cloud the middle position more than I like.

Most formvar is whatever build you order. Most buy the heavy build stuff and never consider the single build. Alot of vintage pickups like the DeArmonds used single build formvar 44 guage, I see alot of this in those types. I was lucky to score a 14 pound spool of that stuff, will probably last a lifetime :-)

If you don't think insulation type makes a difference just buy the cheap poly coated wire and stick with it. I used to be of the mindset but experience proved otherwise.

[Joe Gwinn]

Well, I am going by actual experience from alot of prototyping, rewinding the same pickup structure with different wire, same number of winds, same winds per layer. I just will not use single build formvar in a humbucker, it sounds good but lacks enough treble bite that plain enamel of the same diameter has. It might be good in a bridge pickup but its a better idea to use the same wire in both pickups, if you make minor changes in one pickup, changes you can't even hear, you will hear it in the middle switch position. Using a dark wire type in the bridge will cloud the middle position more than I like.

Most formvar is whatever build you order. Most buy the heavy build stuff and never consider the single build. Alot of vintage pickups like the DeArmonds used single build formvar 44 guage, I see alot of this in those types. I was lucky to score a 14 pound spool of that stuff, will probably last a lifetime :-)

If you don't think insulation type makes a difference just buy the cheap poly coated wire and stick with it. I used to be of the mindset but experience proved otherwise.

The original question was in effect if what you were hearing was due to different insulation type, or due to differences in copper diameter and insulation thickness.

[mootej]

Been grappling with this question on a quest to duplicate some Musicman Sabre guitar low wind pickups. Reading lots of books on the properties of insulating materials:

1. Handbook of electrical and electronic insulating - W. Tillar Shugg

and these from a post on Tesla coils

Dielectric


1. Polymer Engineering Principles, Richard C. Progelhof and James Throne
2. Plastics for Electronics, Martin T. Goosey
3. Handbook of Plastics in Electronics, Dan Grzegorczyk and George Feineman
4. SPI Plastics Engineering Handbook, Society of the Plasitics Industry
5. Electrical Engineer's Handbook, Pender - 4th Edition
6. Phelps-Dodge magnet wire product data

Here's what I am finding out. Inductance of the pickup forms the high pass filter part of a pickup along with the dc resistance. The low frequencies drop off due to the inductance.

At the high end, the coil wind-to-wind capacitance causes the high frequencies to drop off. These two effect lead to the resonant frequency that should be characteristic of the tonal quality of a pickup. The referenced books have a lot of info on the various dielectric constants and dissipation factors of the different insulations. Nylon 6/6, for instance has a high dielectric at around 8. Formvar is low, around 2 or 3. A factor of 4x in dielectric should lead to 4x capacitance which should dramatically affect the resonant frequency. I haven't wound enough pickups to know by ear but on paper, this should be a big effect.

These books also comment on the fact that the dielectric can change over a period of years, mostly dropping, as the insulation ages. Could this be the magical "aged" pickup sound as the capacitance of the coil drops with time and allows a brighter sound? More plausible IMHO than alnico magnet aging. Anyway, the short answer should be "Yes", insulation type should change the sound of a pickup.

Normally magnet wire is considered "better" with a high dielectric but for pickups, just the opposite may be true. Low dielectric allows a brighter sound.

Now, Leo Fender was trying to drop the inductance AND the capacitance of a pickup with the Stingray and the Sabre. He wanted to move the resonant peak out to higher frequency. Fewer turns but an active pickup to compensate for the loss in signal. According to UIUC pickup measurements, it worked.

See

UIUC Physics 498POM Guitar Pickup Measurements

The excel file has some great info on pickups. Fender 8KHz, MM Sabre 14KHz. Love to wind some pickups exactly the same with only the insulation change and have Prof Steve E. and his undergrads measure them.

[Possum]

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You are forgetting eddy currents, if you are talking humbuckers, this is a critical part of the equation, every alloy has a different effect on tone, and there is alot of metal in a humbucker. In single coils eddy currents happen with alnico and varies by type of alnico.

As far as "aging" coils getting brighter, its really the other way around, they get darker. But thats not really been proven either, all I can tell you is if you rewind a PAF with modern wire it gets brighter. Some think the copper back then was less pure, but no one has done the lab work to find out. The insulation on plain enamel formula used now isn't the same as used back in old days, formvar is about the same though.

A good pointer that maybe the old wire was less pure is that I have a '63 early patent, basically its a true PAF but was wound with poly wire, its as dark in the coils as the plain enamel is though not quite as dark. I have early TTops and by then the pickups are just about shrill in comparison to the '63's coils, part of this is the pole screw alloy but everything else is about the same. One could spend alot of money on lab work but what is the point of proving this or that when we can only get wire from very limited sources made in the modern way. No wire maker is going to crank up and produce wire with old time insulation because those old methods were quite toxic compared to today's procedures.

I was told you could age a coil by using heat, well I tried it and stunk up the whole kitchen, the end result was no change in any of the LCR measurements or ear testing. Smelled good though...

[JGundry]

If you are talking about vintage era Gibson humbuckers PAf's in a way they do have different coil wire on each bobbin. 50's era plain enamel was not sorted min. nom./nom.-min. as it is now. Plus the build thickness varied more that with T-Top era poly wire. In addition the likelihood is pretty big that the screws cois and slug coils for PAF's were wound from different spools of wire. Put all of that together and you have two different types of wire effectively on both coils. I personally think this wire mismatch is part of PAF tone. By the time you get to T-Top's the poly wire being used is more consistent in size and build thickness than older PE.

I think the main difference with old PE is the variation in build thickness. The old wire tends to be darker in color and the the darker wire seems to have a thicker build. But even the old wire varies in build. There is one wire company still making wire on par with old PE wire. But most modern PE is made with different enamel formulation and also seems to be more reliable size wise from spool to spool than the old stuff. All of this effect the tone in a humbucker.

[mickmutante]

I hear a difference in tone among the insulations. Especially comparing SPN and Plain Enamel. But everyone's ears are different.
.

What about SPN vs. Formvar or PE...??
I have build some pickups but not as many to hear the differences....

[LtKojak]

If you are talking about vintage era Gibson humbuckers PAf's in a way they do have different coil wire on each bobbin. 50's era plain enamel was not sorted min. nom./nom.-min. as it is now. Plus the build thickness varied more that with T-Top era poly wire. In addition the likelihood is pretty big that the screws cois and slug coils for PAF's were wound from different spools of wire. Put all of that together and you have two different types of wire effectively on both coils. I personally think this wire mismatch is part of PAF tone. By the time you get to T-Top's the poly wire being used is more consistent in size and build thickness than older PE.

I think the main difference with old PE is the variation in build thickness. The old wire tends to be darker in color and the the darker wire seems to have a thicker build. But even the old wire varies in build. There is one wire company still making wire on par with old PE wire. But most modern PE is made with different enamel formulation and also seems to be more reliable size wise from spool to spool than the old stuff. All of this effect the tone in a humbucker.

Well, all this tends to support my "blasfemic" statement:

The best PAF p'ups are being produced TODAY, and not by just one but by MANY producers, and not only boutique winders but also mass-producing producers as well.

Are you with me on this too?

[Chadheckler1]

So if I wanted to wind one coil with 42 and one with 43, what would I want to watch to make the two coils balanced as far as humbucking properties? resistance? number of turns? Total area of the wire?

I think you would match the # of turns to get the best humbucking possible...but you could try +/-1000 turns with respect to the other bobbin if you wanted to try and tweak your tone and still get good humbucking properties. Resistance is not as important as turns. The area of the coil will change the tone but I don't think that it has a large effect on the coils ability to reduce hum (Unless you get crazy with the size)

[Mark Hammer]

Anything that changes the dimensions of the coil will change a number of outcomes. The inductance can be different. The cumulative DC resistance can be different if the outside circumference is larger. In that respect, noticeable changes in the insulation thickness can have the same cumulative impact as simply altering the height of the to-be-filled area of the bobbin or coilform, or using the same height/width of bobbin but having the polepieces inserted in a plastic core vs "naked" with the wire snuggled right up against it.

But note that I said "cumulative". The impact of insulation thickness on coil dimensions/properties of a small number of turns is negligible. So, if I underwind a coil, insulation thickness differences should have less impact than if I overwind it.

Given that, one might expect that insulation thickness has a very noticeable impact on single-coil pickups with 7500+ turns, even when wound to the same # turns on the same polepieces and bobbin, but much less impact on HB pickups where the total number of turns is often much smaller.

So, I guess before people get all "wound up" about winding, they should probably consider what sort of pickups they draw their experiences with insulation thickness from. Some may be thinking about contexts where insulation has the least impact, and some thinking about where it has the most.