Humbucker Pickup Rewind

we bought an Epiphone SG, the G-400, made of nice Mahogany from China, for $300.

nice lookin axe, but it does have it's problems, like a bad nut and terrible pickups,

we can DIY a new bone nut, there is a grave yard right down the street, if someone complains about the smell, tell em we have a DIY dentist shop in the garage, 
but those pickups, why sink 300 bucks in pickups into a 300 dollar guitar?

souping up a sparrow hawk does not make an eagle, so we go cheap and rewind.

maybe set the DCR of the bridge pickup at 7.6K instead of 15.25 k ohms like the stock pickup,

this will put us right between the Billy G's Pearly Gates bridge pickup at 7.4K and the Jimmy Page #1 bridge pickup at 7.8K,

with any luck, we will end up with Duane Allmans 58 PAF sound, 

so lets get under the hood and take a look,

Go baby, go!

now if you take apart one of these guys, you have to start taking notes, because you have 4 wires, a N-S magnet, reverse wind on one of the coils, screws on 1 side and pole pieces on the other, lots of options when reassembling on what goes where,

there are some cool links on this just in case you get stuck,

like a pickup wiring link,

http://www.1728.org/guitar1b.htm

and a magnet replacement link,

http://www.projectguitar.com/tut/barmagswap.htm

here is the guts, notice the melted wax from the low wattage soldering iron,

that magnet has the edges polarized to north and south, the screws and pole pieces transfer the mag field to the top of the pickup,

Jimmy and Willy use alnico 2 for their magnets, you can get alnico 5 which has a slightly different sound, or ceramic for max gauss,

South Pole usually goes towards the screws, which is nearest the bridge,

you can go either way, if you like Peter Green's sound, then spin the magnet and you will have out of phase bridge and neck pickups without flipping the coax around, this will retain your Start-Finish orientation in relation to the coax hookup,

North should be marked with a black stripe or black dots as seen in this hard to see pic,

black and red are used on magnet schematics for N and S,

wtach out for color codes on the wires, everybody uses something different, this one has two wht leads and a wht and black, how the poor factory workers knew what was the Start and Finish on a coil with two white wires is beyond me, 

if you notice on the first link i posted, there is even a case where they use wht for a start on one coil, and black for a start on the other, they use wht for + polarity i guess,

digi cameras are also a help in taking notes on wiring,

i did some inductance tests on the original pickup just so i would have a comparison of how the new coils stack up to the old, used 100hz and 1 khz at 200mv, 1 volt and 20 volts

inductance stayed pretty constant with level, figured out that this is because this is mostly an air core inductor with a few chunks of steel and a distant magnet for a core, so the BH curve for screws and pole pieces is such that the inductance is pretty linear with respect to level, unlike a typical transformer,

DCR will usually be higher on the coil with the  screws, unless it is an original PAF, which could have various DCR's due to the fact that they just stopped winding when the bobbin got full, no turns counter required, this is one reason why vintage sound is kind of the luck of the draw,

Henries for the stock hi turns coil were about 8 H for 1 k hz and 24 H for 100 hz,

we are going to leave off the pickup cover and paint one bobbin with white lacquer so we can fool the blues freaks down at Charlies into thinkin we have super rare mismatched bobbins from an original PAF,

original pickup had about 14,000 turns compared to the 9600 we want to spin on, no wonder the tone suffered so much, you can overwind for a hot pickup, but the law of diminishing returns will catch up eventually,

now the way a humbucker works is that you have one top back wound coil and one top forward wound coil, (this is pickup winders jargon for regular wind and reverse wind, or clockwise/counter clockwise, whatever you want to use), you have a south pole for one coil and a north pole for the other, so with the flipped magnetic polarity and a reverse wound coil, you end up with two coils that will be in phase, so when you series connect them, you have a strong signal.  when hum enters the windings, which act as nice antennas for noise, the hum does not care about the magnet, it is out of circuit so to speak, so since the hum is hitting both coils, and one coil is reverse wound, one coil will be out of phase and the hum cancels out,

this was figured out by a guy named Butts and a guy named Seth Lover, who both applied for patents as they were building the same thing at the same time,

ok we spun on 4780 tuns of #42 nylon coated wire, now we can use color coded leads for start and finish hookup,

wrap the untinned magnet wire around the stripped lead and then solder, this will keep the magnet wire from being heated twice, which will make a stronger connection as the big wire soaks up a lot of heat,

ok we have both coils wound and assembled onto the back plate with a flipped magnet having North energizing the coil with the screws so we can jam out some Big Mac tunes,

DCR came out to 7.60 ohms, the wire snapped on the second coil right when the bobbin was just about full, somebody must have known what resistance we needed,

ready to wire the coils to the coax lead,

stuffing the coil assy back into the cavity,

Henries came out to be about 12 at 100 hz and 2.8 at 1  khz, so we should have a lot more high end coming out of this thing, i wound the coil with a lot of space between each turn so the leakage C would be low, strung it up with 011 GHS Boomers, we are gonna solder up the coax in the cavity on the back and let the neighbors have it, 

you can also wire the two coils in paralell and keep the humbucking thing, output will be off by about 30 percent but you will get more high end, we might just do that  to the neck pickup instead or rewinding, you end up using the bridge pickup most of 90 percent of the time anyway,

will report on results in a bit,

jeez what a difference, can't put this thing down, let the neighbor try it and i had to pry it from his hands,

turned a dumpster guitar into a keeper, my heart is soaring like an eagle,

to bad Epiphone put in those weird pickups, all they had to do is use less copper and they would have had a problem keeping these things in stock,

a few notes on the pickup, i did not pot it in wax like 98 percent of all pickups use today, and when you hand wind, you can space the turns out, i bet seymour duncan has his machines set up to wind side by side turns so he can get more wire on and make it look neater, this rolls off the hi end

so no wax and random winding will get you closer to the 59 PAF sound,


i will try to put up a sound bite,

Good stuff CJ - nice to see this.

>and when you hand wind, you can space the turns out,

On my winder I have taken to setting the spacing to about 3x the wire gauge, so for 42AWG, which is 0.063mm, I set the lateral arm movement for 0.2 mm spacing. This seems to reduce the winding capacitance quite nicely, and still looks quite neat.

cool!  do you add more turns to the coil with the adjustable screw coil like a lot of people do?

i ended up with a few hundred more tuns on the "dummy" coil but it still sounds killer,

i wonder if the imported pickups have weak magnets that make them more like an Al 2 rather than the Al 5 that they spec,

why do they usually put more turns on the neck pickup? you would think that with the extra string movement that they would put less, plus you want a brighter pickup there to get rid of the muddy bass,

how do you check the resonant  frequency?

I haven't made many humbuckers - mostly been focusing on the single coils, P90s and of course the hexaphonic pickups!



>why do they usually put more turns on the neck pickup?

Seems daft to me. I think with vintage single coils like strats and Teles, there are more at the bridge to get a balanced set. For a strat set, I've been doing something like 7000 on the neck, 7500 on the middle and 8000 turns on the bridge, more or less if you want a 'hot' set or something brighter.

>how do you check the resonant  frequency?
Still at the 'does it sound good' stage - haven't invested in any fancy pickup testers. This spreadsheet is pretty handy though to calculate it....

http://guitarnuts2.proboards.com/index.cgi?action=display&board=reference&thread=3627&page=2

The problem is getting a good value for the winding capacitance, which is hard to separate from the inductance and resistance.

holy cow a seprate pickup for each string awesome!

hey, can i convert this neck humbucker that i am rewinding into a stereo pickup by drilling out 3 pole pieces on one side and unscrewing 3 screws on the opposite side?

would it still humbuck if i reverse wind one coil?

wow, youlube does not require any registration, just point and click!

here ya go>

http://www.youtube.com/watch?v=LZJD_kRjEPQ&feature=youtu.be

this one is very interesting, shows a comparrison between hand wind and machine wind>

http://www.youtube.com/watch?v=CW_ZW3aMMB8

CJ said:

hey, can i convert this neck humbucker that i am rewinding into a stereo pickup by drilling out 3 pole pieces on one side and unscrewing 3 screws on the opposite side?

would it still humbuck if i reverse wind one coil?

Click to expand...

Yup, that would work, but you won't get great separation as the coils are still wound under all the strings. I did six separate mini-coils.

CJ said:

http://www.youtube.com/watch?v=CW_ZW3aMMB8

Click to expand...

That one is great. Can't quite get my head round his testing. How does the response of the transmitter coil not get superimposed on the sweep? Or is that the constant current bit? Or some other calibration procedure not shown?
Thanks!

Those Hexapups sound amazing. Check out the sound clips on Stewart's website, y'all.

http://xaudiaelektrik.blogspot.co.uk/2013/01/hexapup-samples-wiring-and-technical.html

those sound pretty amazing!  lots of options for sure,

could you patch that into a guitar synth?


this neck pickup that i took apart was wired inside out, that is, both coils were wound the same direction, but they wired it finish to finish, with the starts going out to the coax, this is still a humbucker but i do not know why they did this s there is no split coil switch on the guitar,

DCR was about 8K, about half that of the bridge pickup,

we wound 4500 turns on each bobbin this time to see if it will cancel out the hum a little better than say a 4500-5000 turn set of coils,

the magnet seems stronger than the bridge magnet, so some variance here,
maybe that is why i get about the same Henries as the bridge pickup even though i have less turns,

i wonder if i degaussed that first magnet with that huge soldering iron with the 1000 watt coil inside?   


we have DCR at about 7.25 k, so this should give us more treble which is fine since it had too much hi end rolloff,

if you lose track of the S and F while doing these coils, you cn get your phase right by checking Henries with the wires hooked up both ways, you will get a slight increase when they are phased right,

DCR really changes with temp, after i took the cover off, the pickup was pretty warm, and the DCR went up 1000 ohms,

going to put a cap in series to get the res freq,

looks like a 0.0001 uf in series at 1 khz will do the trick,

if you use 100 hz you need a real small cap as the Henries are a lot higher,

so i think we will get better results at the higher freq,

ok looks like the r3educed turns neck pickup resonates at 11.5k, not bad! i spaced the windings out quite a bit, only about 10 turns per layer with the micro wire,

this neck pickup really sounds sweet after the rewind,

and i did a hum test, the bridge pickup has a 320 turn difference, the neck pickup is matched at 4500 each,

with the amp cranked for hum level testing, there is complete cancellation with the neck pickup, and residual hum with the bridge pickup,

i do not see any gains for mismatching turns, and i do see a quiet guitar with the turns perfectly matched, wonder what these pickup makers are thinkin,


Heads Up! if you do a rewind job on an SG, do the neck pickup first, as the coax cable goes into the bridge pickup cavity and out another hole, you can not get the wire thru with the bridge pickup installed, even with a piece of bus wire,

i had to remove the bridge pickup again, doh! 

Hi CJ,

You can re-magnetise the soft Alnico magnets that you find in most guitar pickups. Pop them between two STRONG neodyniums with a few layers of tape on so you can get them apart afterwards. I do it in my vice, sticking one neodynium magnet on each jaw, and then close the gap until it is a couple of mm wider than the one you want to polarise. Slide the magnet through a couple of times and you are done!

Alnico magnets do seem to vary in Gauss by quite a few %.

MagnetoSound said:

Those Hexapups sound amazing. Check out the sound clips on Stewart's website, y'all.
http://xaudiaelektrik.blogspot.co.uk/2013/01/hexapup-samples-wiring-and-technical.html

Click to expand...

Thanks for the kind words! 
And thanks also to Tony (Zayance), who is a whiz with PCB designs - couldn't have done it without him.