ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

Insulation tonal differences?

5/4/2006 9:50 PM
Ken	Insulation tonal differences? I'm really curious... First I was reading about plain enamel wire, and it's 'tone'. Then, I learned about Formvar, and it's specific tone. Then I come here, and I'm reading about stuff like 'armored polythermaleze' wire. Seriously, how much does different insulating materials on coil wires have to do with actual pickup tone? Does different insulation thicknesses REALLY make that much of a difference? Ken

5/4/2006 9:50 PM

Ken

Insulation tonal differences?

I'm really curious... First I was reading about plain enamel wire, and it's 'tone'. Then, I learned about Formvar, and it's specific tone. Then I come here, and I'm reading about stuff like 'armored polythermaleze' wire.

Seriously, how much does different insulating materials on coil wires have to do with actual pickup tone? Does different insulation thicknesses REALLY make that much of a difference?

Ken

5/5/2006 4:18 AM
Dave Stephens	yes it does, its all about capacitance, heavy build wire should be called low capacitance wire......

5/5/2006 1:08 PM
Greg Simon	Think about it....as you wind the coil, if you use thicker insulation, the wire will build differently on the coil with less wire per turn than if the wire insulation is thinner. This all assumes that the tension and wire gauge is kept the same between coils but that you just change from say polysol to heavy formvar. This has to affect something, and it definitly does. Changing the tension, or the wire gauge also change the sound, and you can see that winding pickups is more an art than anything else, and requires experimentation to a certain degree. Greg

5/5/2006 1:08 PM

Greg Simon

Think about it....as you wind the coil, if you use thicker insulation, the wire will build differently on the coil with less wire per turn than if the wire insulation is thinner. This all assumes that the tension and wire gauge is kept the same between coils but that you just change from say polysol to heavy formvar. This has to affect something, and it definitly does. Changing the tension, or the wire gauge also change the sound, and you can see that winding pickups is more an art than anything else, and requires experimentation to a certain degree.

Greg

5/5/2006 9:11 PM
Ken	So, what you're saying is that thicker coil wire insulation will change the way the coil reacts, due to the fact that the coil will be a larger physical size for the same turn count. I always thought that was an 'old wives' tale, but I can see the logic. Years ago, I had a friend look for 'barrel wound' single coils, he said they had a 'fatter' tone. But, if you wind a coil with straight sides, you can get more wire into the coil. What about differing insulative materials? If two insulated wires close together in parallel have capacitive frequency rolloff effects, would differing coatings like Formvar or 'thermaleze' have different tonal effects simply due to the differing dielectric materials? I'm going to have to get some different wire types and experiment. I learn something new from every pickup I make, every one I ever made is documented for every variable, and for any tonal 'variations' I find. You're right, this is an art... I have to explain to my customers sometimes that you don't just throw wire onto a coil and it's done. Ken

5/5/2006 9:11 PM

Ken

So, what you're saying is that thicker coil wire insulation will change the way the coil reacts, due to the fact that the coil will be a larger physical size for the same turn count. I always thought that was an 'old wives' tale, but I can see the logic. Years ago, I had a friend look for 'barrel wound' single coils, he said they had a 'fatter' tone. But, if you wind a coil with straight sides, you can get more wire into the coil.

What about differing insulative materials? If two insulated wires close together in parallel have capacitive frequency rolloff effects, would differing coatings like Formvar or 'thermaleze' have different tonal effects simply due to the differing dielectric materials? I'm going to have to get some different wire types and experiment.

I learn something new from every pickup I make,
every one I ever made is documented for every variable, and for any tonal 'variations' I find.

You're right, this is an art... I have to explain to my customers sometimes that you don't just throw
wire onto a coil and it's done.

Ken

5/6/2006 12:07 AM

Dr. Strangelove

Ken wrote:

quote:
"What about differing insulative materials? If two insulated wires close together in parallel have capacitive frequency rolloff effects, would differing coatings like Formvar or 'thermaleze' have different tonal effects simply due to the differing dielectric materials?"

Yup.

The insulation quality that determines capacitance is called "dielectric constant".

A bigger dielectric constant means more capacitance. Thicker insulation means less capacitance. Most polymer insulations have a value around 3.0-4.0.

For comparison, here are a few more values:
1.0 - AIR
2.1 - paraffin (potting)
2.8 - polystyrene (used in coil dope)
3.0 - polyester (insulation)
3.0 - vinyl formal (AKA formvar)
3.3 - nylon (insulation)
3.9 - polyimide (aka kapton, insulation)
77 - water

All of these values change with applied frequency, some more than others.

Many more constants:
<http://www.clippercontrols.com/info/dielectric_constants.html>

-drh
--

5/6/2006 11:13 AM
Ken	This would explain why 'partial potting' would work... You are replacing for example air (dielectric constant or DC of 1.0) with, say, paraffin (DC 2.1). Just replacing the air will shift the capacitive rolloff of the entire pickup by the new amount, also the pickup's 'tone'. Each differing potting media has its own DC too, so shellac sounds different from paraffin, which sounds different from beeswax, etc. You can finetune the response changes somewhat by changing the amount of time the pickup is in the potting medium, and also by the medium's actual viscosity. Not to mention the DC of the wire insulation you're using, and the thickness of the insulation... Ken

5/6/2006 11:13 AM

Ken

This would explain why 'partial potting' would work...

You are replacing for example air (dielectric constant or DC of 1.0) with, say, paraffin (DC 2.1). Just replacing the air will shift the capacitive rolloff of the entire pickup by the new amount, also the pickup's 'tone'.

Each differing potting media has its own DC too, so
shellac sounds different from paraffin, which sounds different from beeswax, etc.

You can finetune the response changes somewhat by
changing the amount of time the pickup is in the potting medium, and also by the medium's actual viscosity. Not to mention the DC of the wire insulation you're using, and the thickness of the insulation...

Ken

5/6/2006 1:21 PM
moocow	Sorry, but you guys are getting way off track here. The capacitance of a pickup is very small, around 70-100pF or so. The capacitance of a guitar cable is much larger, from 600 to 1000pF is typical. This means the guitar cable capacitance dominates the pickup capacitance, and any small changes in pickup capacitance will be inaudible. Even if pickup capacitance were important, you would need to measure the capacitance to see if it even changes when you change a parameter in your pickup. It is one thing to come up with a theory as to how the capacitance changes, but very few people actually take the measurement to verify their theories. I'd be very curious to see the capacitance numbers but so far no one has ever made measurements that show one kind of pickup construction method produces less winding capacitance than another. Anyway, I have done these sorts of calculations, simulations, and measurements and I am trying to help you pickup winders understand what is going on with your pickups. If you are hearing a difference, that's fine, but don't waste your time pursuing these capacitance theories. I've already done that for you, so if your pickups sound different because of winding, potting, etc., that's great, but they sound different for some other, unknown reason.

5/6/2006 1:21 PM

moocow

Sorry, but you guys are getting way off track here. The capacitance of a pickup is very small, around 70-100pF or so. The capacitance of a guitar cable is much larger, from 600 to 1000pF is typical. This means the guitar cable capacitance dominates the pickup capacitance, and any small changes in pickup capacitance will be inaudible.

Even if pickup capacitance were important, you would need to *measure* the capacitance to see if it even changes when you change a parameter in your pickup. It is one thing to come up with a theory as to how the capacitance changes, but very few people actually take the measurement to verify their theories. I'd be very curious to see the capacitance numbers but so far no one has ever made measurements that show one kind of pickup construction method produces less winding capacitance than another.

Anyway, I have done these sorts of calculations, simulations, and measurements and I am trying to help you pickup winders understand what is going on with your pickups. If you are hearing a difference, that's fine, but don't waste your time pursuing these capacitance theories. I've already done that for you, so if your pickups sound different because of winding, potting, etc., that's great, but they sound different for some other, unknown reason.

Page 1 of 4

Next>

Last Page>>