30-40 AWG What is it good for ?

[Lyrebird Steve]

Hi Guys,

I've just picked up a job lot of gear and supplies passed down to my uncle who passed them down to me.

It comes from an old electrical engineer who would wind transformers and motors (?) and the occasional guitar pickup. Most of it sourced in the 60s/70s but some is more modern.

Amongst the boxes was a number of boxes of magnet wire ... most of the labels were faded too badly, so I've had to double check every spool with a micrometer.

Most of the wire is between 30 and 40 AWG.


There's an very large spool of 40 AWG ... about 5kg (11lbs) and a huge amount of 36AWG

Are these of use in any model of pickup ?

Thanks
Steve

[David King]

Sure, good for any of the low to medium impedance designs like Alembic.

[big_teee]

Hang on to those nifty Wooden Spools.
That all looks really old.

[Mark Hammer]

The larger gauges can be used for making chokes for power supplies, or inductors for speaker crossovers or wahs. You can buy coilforms for making highly-prized wah inductors, like this one: Wah Inductor Kit

(I misspelt a word above, and quickly realized I wasn't doing anyone any favours by linking them somewhere that they could buy a "coliform" )

[charrich56]

I'm winding with #32 to #36. You should put some of the spools up on Ebay if you don't plan to wind low to medium impedance pickups.

[big_teee]

I'm winding with #32 to #36. You should put some of the spools up on Ebay if you don't plan to wind low to medium impedance pickups.

Remember he Is Down Under in Oz land.
It would probably not be feasible to ship across the big Pond!

[mojoatomic]

Also, Charlie Christian type pickups are usually wound with #38 -

[Lyrebird Steve]

Also, Charlie Christian type pickups are usually wound with #38 -

Was thinking of making a Blade type Humbucker using some of the 40 AWG, do I need to use ceramic mags if the DCR is low (ie < 4kOhm)?

[charrich56]

No, for some reason the ceramics are associated with some of the mega-crusher blade or rail pickups such as the Dimebag Darrell pickup, at least in some people's minds. Ceramic magnets in and of themselves aren't necessarily bad or good; it depends on the rest of the design. To quote the late Bill Lawrence, "magnetism is magnetism." You can use any magnet type with any impedance range in terms of windings that you want. That's part of the fun. I am experimenting with a low-impedance rail humbucker with ceramic mags right now in the midst of too many other projects.

Since you are going to build a rail humbucker it's natural to infer that you aren't going to use Gibson vintage construction for the pickup for the most part. So give the ceramics a whirl if you would like. But you don't have to. You can search the forum for some other posts and opinions on this.

Practically, if you check out Mojotone for example, ceramics are the only magnet option they say works with the single-coil size blade humbucker parts they sell, and another ceramic part number is used for their rail-type full size humbucker parts (albeit 2 or 4 of them per pickup).

If you wind with #40 you should end up with a medium impedance pickup of about 1K to 4K DCR as a guess depending on whether you go series or parallel with the coils. Alembic has used this general formula for years. Their approach is/was to put the self-resonant frequency above the audio band and voice the pickup with electronics (state-variable filter) which can emulate the resonant peak of a "normal" pickup, but with the flexibility of tuning to taste.

If you stay with a passive pickup the pickup will tend to be "hi-fi" in nature, and won't have as much output, which might lead you to the idea of a smple onboard preamp. One of these would work fine with about 6-10 dB gain from a Stratoblaster type FET preamp. You could voice it without using the fancy Alembic approach, and end up with something that you might like.

If you don't know about this already, Salvarsan on this forum has written an excellent coil estimator which can take the bobbin dimensions and estimate the number of turns for a given wire gauge and DC resistance. It is a self-contained HTML page which can be downloaded and run locally. I use it quite a bit and am very grateful for this tool.

Here's the link:
Coil Estimator

Just as another suggestion, you might want to just strip down an old pickup or two and rebuild it with the old hardware but rewind the bobbins with your own formula. That's what I did to start, and still do for experimentation.

An Extech or DE-5000 quality LCR meter will earn its place as your essential companion on the journey.

-Charlie

[David Schwab]

I made medium impedance pickups with ceramic magnets for a number of years.

Ceramic magnets are used a lot in over wound pickups, because they tend to sound brighter than alnicos, because they are often stronger.

I currently use 40 gauge wire in one model.

[charrich56]

David,

Oh, you're right, I should have brought that up, too. The ceramic magnets are/were used in massively overwound (like 15-20K+ DCR), therefore dark, pickups to brighten them up like you said.

I can't help thinking humorously how far away from that world I'm getting right now with 700 to 900 turn, 50 ohm DCR, 30 millihenry pickups. I suppose you could call them "massively underwound." ;-)

-Charlie

[Lyrebird Steve]

I currently use 40 gauge wire in one model.

David,

what types of Mags would you recommend for a Strat blade pickup wound to 3,000 ohm (6000 turns of 40AWG) ?

thanks
Steve

[David Schwab]

David,

what types of Mags would you recommend for a Strat blade pickup wound to 3,000 ohm (6000 turns of 40AWG) ?

thanks
Steve

Well what magnets can you find in the right size? That's always the question. Is it a single coil? Or a humbucker? For the Strat size humbuckers you can't find alnico magnets that narrow. The ceramics work fine.

[David Schwab]

David,

Oh, you're right, I should have brought that up, too. The ceramic magnets are/were used in massively overwound (like 15-20K+ DCR), therefore dark, pickups to brighten them up like you said.

I can't help thinking humorously how far away from that world I'm getting right now with 700 to 900 turn, 50 ohm DCR, 30 millihenry pickups. I suppose you could call them "massively underwound." ;-)

-Charlie

I've made medium impedance pickups (about 1.5kΩ) with ceramic magnets and steel poles. They sounded very nice.