Wider coils than Jazzmaster pickups?

[epizootics]

Hi everybody,

Has anyone in here experimented with *really* wide coils? The widest I have encountered so far are JM pickups, which I love (wound one yesterday that sounds pretty mean), but it makes me want to see how much further the concept behind those can be expanded. Most of the pickups I make go on home made guitars, so non-standard bobbin shape & size aren't really an issue.

The one problem I can see for now is that a larger portion of the coil, ie. on the sides, would be useless as there would be no string vibrating above it. I assume the result would be an even darker overall sound.

Any thoughts on this?

[Rodent]

if by wider you mean perpendicular across the strings, then these 7-string bass pickups should certainly qualify. they're 145mm long x 32mm wide, and require a custom made cover since none are available in the free market for this 'standard' Bart size



and these are for a bass with 'only' seven strings. there are basses on the market with up to 13 strings - now that a wide (err ... long) pickup!

[epizootics]

Ah, sorry, I meant wider as in flat and wide all around, but most importantly spreading further parallel to the strings rather than just being a longer coil. Nice looking wood covers though!

[big_teee]

If you mean a short height between the flats?
A wide flange across the wound coil, like a P90, or a Jazz Master coil?
If you get wider than that, don't you end up with a darker or muddier pickup sound?
T

[rjb]

If by wider you mean perpendicular across the strings, you can't get much wider than this configuration by Bruce Johnson. I know it's not what you were considering- but there's always more than one way to skin a cat.



Here's Bruce's original post: http://music-electronics-forum.com/t32943/#post301401


-rb

[Chris Turner]

This is the widest I've seen... never heard one, though, so no idea how this kind of thing sounds.

[rjb]

This is the widest I've seen... never heard one, though, so no idea how this kind of thing sounds.

Yup, same idea but with lipsticks instead of "Strat-type" pickups.
I've never seen anyone use that configuration other than on bass.
IIRC, wide sensing window emphasizes the fundamental(?)

-rb

[parentheticalfact]

I've done this quite a few times.
Tonally, RJB is on the right track, more fundamental emphasis. Basically a fat tone with lower emphasis on high harmonics.
Side effect is it becomes a huge antenna for hum.

[epizootics]

If you mean a short height between the flats?
A wide flange across the wound coil, like a P90, or a Jazz Master coil?
If you get wider than that, don't you end up with a darker or muddier pickup sound?
T

Yup, exactly. I have a feeling the flange can be taken a bit further, as Jazzmaster pickups aren't even close to being dark or muddy...I'm curious as to what a few extra millimeters on each side would do, flattening the bobbin accordingly to keep things in the 7-8k area.

[big_teee]

Yup, exactly. I have a feeling the flange can be taken a bit further, as Jazzmaster pickups aren't even close to being dark or muddy...I'm curious as to what a few extra millimeters on each side would do, flattening the bobbin accordingly to keep things in the 7-8k area.

If you wish to stay with standard parts and covers?
You could try 43PE, and, or, 250-300k Pots.
You can increase the turns count a bunch!
That would be my remedy, rather than all the fabrication of custom parts.
Unless you like making custom parts?
T

[epizootics]

I do like to make custom parts! I make my own guitars (no money to buy the gear I like & unlimited access to my dad's cabinet making workshop) and non-standard dimensions aren't an issue. As stated above, I don't want to go over a fairly standard DCR/output, I've never been one for hot pickups.

I guess I'll just give it a try - increase that flare size until it gets too dark. I'll try and post the results on the board as I go if anyone's interested...

[big_teee]

Sounds good. If you like to make parts, make parts.
I prefer to make Pickups, not pickup parts!
Actually going to smaller wire makes the size of the coil smaller for same turn count.
Smaller coil size usally means brighter.
So with 43 same turn count will be more DCR, but not hotter.
You would have to increase turn count to make it hotter.
Anyone else?
GL,
T

[parentheticalfact]

If you wish to stay with standard parts and covers?
You could try 43PE, and, or, 250-300k Pots.
You can increase the turns count a bunch!
That would be my remedy, rather than all the fabrication of custom parts.
Unless you like making custom parts?
T

Turns count and DCR are only part of the picture and while a higher resistance will generally darken the pickup so will a wider coil. Don't forget how important coil shape is to a pickup, which accounts for why most P-90 for tele type pickups don't truly sound like a P-90. Lots of factors to experiment with here to get your desired result.

[epizootics]

Sounds good. If you like to make parts, make parts.
I prefer to make Pickups, not pickup parts!
Actually going to smaller wire makes the size of the coil smaller for same turn count.
Smaller coil size usally means brighter.
So with 43 same turn count will be more DCR, but not hotter.
You would have to increase turn count to make it hotter.
Anyone else?
GL,
T

There's a thought here - I could try awg 43 to brighten up the design, reducing the bobbin's height further to compensate for the thinner gauge but reaching an overall theoretical balance with the darkening of the tone from the flatter shape of the pickup...

[Mike Sulzer]

It makes sense to review how a pickup works in order to understand when a wider coil would have the kind of effects you are interested in.

1. The permanent magnetic field from the pole pieces magnetizes the strings. Right over the pole pieces, the field from this string magnetization points towards the pole pieces. The string magnetization becomes weaker further from the pole pieces along the strings, and it increasingly points along the string rather than towards the pole piece.

2. A turn of wire in the coil produces a voltage that depends on the time varying field from the magnetized vibrating string, but it is only field lines that pass through the loop that count. Furthermore, it is only the component of the field that is perpendicular to the plane of the loop that counts. So the field from the part of the string over the pole piece is very effective since it is strong and points through the coil. But the field from a part of the string that is farther away is both weaker and it points less directly through the coil because the magnetization points more along the string.

3. When you wind more wire on a coil, whether it is by making the coil wider or deeper, you increase the inductance, making the resonant frequency lower, and the resistance, making the resonant peak broader and less high.

4. When you make a coil wider, the turns near the outside enclose the magnetic field from the part of the string over the pole piece just as the turns near the pole pieces do. However, the additional field that the outer turns enclose (from the parts of the string further away from the pole piece) do not add much.

5. If you made the coil very wide, you would get almost nothing. This is because magnetic field lines have no beginning or end. So a field line from the vibrating string that passes directly through the coil loops back to the string. A wide enough coil would enclose this line twice, once in each direction, and so its effect would cancel out.

6. A narrow strat pickup gets nearly all of the field from the most effective part of the string. A wider pickup sees this field more times (because it has more turns), but gets very little voltage from the additional parts of the string that are sampled because these parts are weakly magnetized, and the field mostly points in the wrong direction.

7. You can use information such as this to guide experimentation, but the exact sound you get is only learned by winding it and listening.