Switchable additional winds

[Hout]

Hi all, first post here

I have wound a few pickups for my own basses and I was wondering about the the possibilities of adding an additional circuit to a single coil to get more tonal options.
I am not completely new to this, but by no means any where near an expert, ore like a trial and error diy-er. I did a search and couldn't find anything on it, but since I'm not so familiar with the terminology I might have missed it, so apologies in advance if this has been discussed before.

So here's my idea:
When winding a pickup you stop at a certain point, cut the wire, and lead it somewhere it is fixed and not in the way, and then continue with a new wire, until you end up with an "overwound" pickup. These two coils are then hooked up through a dptp switch so you can switch between running the normal (or underwound) coil to the amp and normal+extra wounds to the amp. I made this following schematic to hopefully explain some more.


As I tried to depict, the coils are wound and wired in the same direction, so there will be no hum cancelling of course. I figure there would be a difference in volume from the two options, so maybe I can fiddle around to get an inline resistor or a trimpot to even out the output.

So what do think? Has anyone tried this? Would it work? Am I overlooking something?

[darkfenriz]

Cool idea, why not.

[LtKojak]

Has anyone tried this?

Your idea is called a "coil tap", and it's been around for ages.

[Hout]

Your idea is called a "coil tap", and it's been around for ages.

There you go So thát's the term
So the wiring schematic, is that correct? Or am I inducing a lot of trouble by using an additional resistor?

EDIT:
As I now know this is called a coil tap, do I actually need to use dpdt switching, or would it suffice to solder a "tap" wire somewhere mid way and just use that one coming out the middle of coil, and one out of the end? Then I could use a normal ON-ON switch for this.

[J M Fahey]

Not sure what you mean by ON-ON , what you need is a SPDT .
Ground is always connected and output is taken either from the full winding or from the tap.
I would not rush to compensate for overwound higher output, user will *expect* it to be louder than the less wound one, otherwise what´s the point?

[Chuck H]

It's also unfortunate that the term "coil tap" is used in novice circles to indicate splitting humbucker coils and running them as singles. Which, of course, is a coil split. But some bigger name manufacturers make the same error in the lit sometimes. I can only assume this is an attempt to communicate effectively with the electronically illiterate guitar players they cater to. At least I hope so. But misuse of the term makes it hard to know what someone is selling.

[epizootics]

That's one of the cool things when diving into the wonderful world of guitar pickups - you end up reinventing the wheel every other week, which is comforting in a way because it puts the process back into a human perspective. The very fact you reach the same conclusions as pickup makers back in the day should tell you you're on the right track!

You can indeed use an ON-ON SPDT switch for your wiring, simply ditch the resistor. But you can make any number of taps - as many as you can fit eyelets on the side of your flatwork! You can then tap your coil from the 'in' wire to any of the taps you want, or from any tap to any subsequent tap. This makes for a wide tonal flexibility. Some people use a rotary switch for this.

[Hout]

Thanks for all the advice! Very interesting world indeed, inventing and engineering your own sound! SPDT ON-ON was what I was trying to say with normal ON-ON, the correct abbreviation didn't come to mind.
Just for clarification, as you all seem to oppose the resistor, increasing the winds changes the tonal characteristics as well as the output volume, right? I'm not fond of changing my bass' output volume much as I find it messes with my pedal chain, so that's the reason for the resistor. Or will adding a resistor sort of undo both volume and tonal characteristics of the extra winds?

[Chuck H]

I should probably let the pickup guys handle this, but...

I think a resistor of any value that would significantly stave LF output would also roll down the resonant peak like turning down the volume control on your guitar. Making the overall signal balance favor LF for the relative amount of output.

Maybe a capacitor instead?

[Antigua]

Hi all, first post here

I have wound a few pickups for my own basses and I was wondering about the the possibilities of adding an additional circuit to a single coil to get more tonal options.
I am not completely new to this, but by no means any where near an expert, ore like a trial and error diy-er. I did a search and couldn't find anything on it, but since I'm not so familiar with the terminology I might have missed it, so apologies in advance if this has been discussed before.

So here's my idea:
When winding a pickup you stop at a certain point, cut the wire, and lead it somewhere it is fixed and not in the way, and then continue with a new wire, until you end up with an "overwound" pickup. These two coils are then hooked up through a dptp switch so you can switch between running the normal (or underwound) coil to the amp and normal+extra wounds to the amp. I made this following schematic to hopefully explain some more.
[ATTACH=CONFIG]47092[/ATTACH]

As I tried to depict, the coils are wound and wired in the same direction, so there will be no hum cancelling of course. I figure there would be a difference in volume from the two options, so maybe I can fiddle around to get an inline resistor or a trimpot to even out the output.

So what do think? Has anyone tried this? Would it work? Am I overlooking something?

An under appreciated aspect of coil tapping is that, suppose you wind it to 7,000 turns, then tap it, then wind it another 2,000 turns for a total of 9,000, when you use the 7,000 tap, it will not sound the same as a coil that was wound to 7,000 turns without the tap, because those extra 2,000 turns of wire remain in the circuit as a capacitive coupling. The amount of capacitance added by that extra bulk of coil is audibly significant.

[Jason Rodgers]

If the layers affect one another, can you use this to create some tonal variation? Here’s a scenario: say you wind 5000 turns, tap it, wind 5000 more, put a 4-wire lead on the pickup, then hook it up to a 3-way toggle. The toggle gives you inside coil, full series, outside coil. Would the inside and outside taps sound different enough to be worth it?

[Antigua]

If the layers affect one another, can you use this to create some tonal variation? Here’s a scenario: say you wind 5000 turns, tap it, wind 5000 more, put a 4-wire lead on the pickup, then hook it up to a 3-way toggle. The toggle gives you inside coil, full series, outside coil. Would the inside and outside taps sound different enough to be worth it?

If both halves are 5000 turns, both halves will perform near identically, regardless of whether the coil is on the inside or the outside.

[copperheadroads]

The coil on the outside is quite larger than the inside coil ,I wouldn't consider it half or even

[J M Fahey]

Inner and outer halves will sound slightly different, not sure this will merit the switching complication, maybe you can hear something playing alone in a basement at low volume and *focusing* on it, but I guess onstage, loud, and with other musicians around any difference will be lost.

Physically: output level and inductance remain the same, resistance will be somewhat higher ... but main component of pickup impedance is inductance, not resistance; capacitance will be slightly higher, although difference may be swamped merely by choice of a different guitar cable, so...

But in any case you are asking here things you should be experimenting

[Jason Rodgers]

Oh, for sure! I have a guitar in mind that will have one pickup and very simple controls (maybe just volume with push-pull for tap or coil cut, maybe just a toggle for full/cut/off) and this thread came up at the perfect time.