Jul 3, 2016

"Reel Character" Woodybucker

The second hand-wound pickup I've built by hand with the "Reel Great" pickup winder, the"Woodybucker", an asymmetrically wound humbucker with wood bobbins and hex polepieces.  A humbucker is an even bigger pain to wind than a single coil but opens up a lot of opportunities for unique tone as well.

The winding process went almost identically to my previous pickup with a few exceptions as I learned from before.  The biggest of these was a simple change in my setup with huge real benefits.  The layout with the wire spool vertically introduced a lot of friction and wobbling that was all corrected by mounting it horizontally clamped to a chair instead of to the table.  

Before mounting horizontally, I had a break every ten minutes it seemed, but after swapping layouts it didn't break a single time except once when I tried sanding through the insulation to check the resistance and went a little too far.  This change makes it feasible that I might expand production and start selling a few pickups rather than calling it off due to the headaches.

With the bobbin nearly fully wound
I opted for an asymmetric winding; the two bobbins have unequal amounts of wire wrapped around them and uneven resistance values.  The coil closer to the bridge (screw coil) is wound to 4.5K ohms, while the neck side bobbin (slug coil) is wound to a hotter 5.5K ohms, for a fairly strong mismatching and a total resistance of almost 10K ohms even.

The unequal coils should allow a more single-coil like sound to come through with the higher voltage of a two-coil humbucker.  It also has most of the hum-cancellation properties but not quite all of them, allowing a fraction of the hum of a single coil through.  However, this is a more than acceptable compromise in my opinion because very closely matched humbucker coils also cancel out some of the high frequencies, leading to a more muffled sound than bright and punchy single coils.

I also took a creative route to potting; instead of dealing with the dangers and pains of dunking it in hot wax, I "painted" clear coat polyurethane into the coils several times during wrapping.  This ensured the poly got all the way inside the coils and hardened, reinforcing the wraps through and through.  This does make it near impossible to rework the windings, unlike wax, but isn't something that I'm worried about in this case.

After sealing the coils with poly and letting them dry for a few hours, I wrapped each in teflon tape to fully protect the wraps.  I assembled the bobbins on the wooden bobbin plate, and the metal baseplate to the magnet and plastic spacers.  I took the small leads from the bobbins and soldered them together in series, and then tucked those wires under another level of teflon tape.

A wrap of Gorilla tape around that fully protected the very thin vulnerable lead wires.  It's not a terribly aesthetically pleasing exterior from the sides but does a better job protecting the thinnest wires.  I ordered a black plastic cover that I should be able to modify for a more aesthetically pleasing and even more solid exterior.

The (just about) finished product here; clocking in at exactly 10K ohms, it should be a little hotter than the typical vintage PAF (around 8K ohms) and a bit cooler than modern metal pickups, at 12-14K ohms.  The asymmetric coils combined with scatterwinding should allow some very clear and bright treble to shine through for a humbucker.  I don't yet have a guitar to test it in but did some very rough preliminary testing by holding it over another guitar, and it sounds like a good humbucker should, stay tuned for more in-depth studies once I have the project guitar I have in mind to try it out.

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