#1
WARNING!! WARNING!!: This is dangerous surgery these instructions outline. You could very easily make your pickups irreparable. I take no responsibility if you do screw it up!

ALSO!! After this your pickups WILL be microphonic (if you had covers and put them back on) unless you re-pot them.


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All that said, welcome to my thread for how to coil tap your two conductor pickups, or how to turn them into a three or four conductor setup.

TABLE OF CONTENTS

-1 How Coil Tapping Works
-2 Getting Naked (Removing Covers)
-3 Beginning Surgery
-4 Finding The Connecting Wire
-5a Four Conductor Wiring
-5b Wire Color Table
-6 Finished!


-1 How Coil Tapping Works


So first we'll outline what we are doing. The humbucker pickup as you may know is essentially two single coil pickups right up next to each other that are wound backwards to each other and have opposite polarity of the poles. What coil tapping does is play with the wiring in the way these two are connected.

Here's a crude diagram


As you can see, in between the coils, they connect. Now in a real humbucker (as opposed to some crappy drawing) this is usually a piece of insulated wire (not just the two pieces of winding soldered together). This is a very good thing, because we can work with semi-fat insulated wire as opposed to tiny tiny 43 gauge pickup winding wire, which is near impossible to work with.

So, now how does coil tapping work? As you can see, if we grab the place where they connect and just short that to ground, the bottom coil is essentially ignored, as electricity takes the path of least resistance. Awesome! now it's a single coil.

Okay now down to brass tacks, lets get crackin.

-2 Getting Naked (Removing Covers)

First off, you want a nice clean flat large work space that you can do careful precise work in, a piece of newspaper on the kitchen table works awesome for this. The newspaper is especially recommended because if your pickups are potted, this will prevent the wax from getting all over the table (and to clean up you just fold up the newsprint like a taco bell wrapper and throw it away).

Here's my setup


As you can see I also have a small screwdriver. This I use to poke around in the wax. Anything small and pointy would work.

Now if your pickups have covers, keep reading, if they don't, then move along, these are not the droids you're looking for. Ok so, chances are your pickup covers are soldered to the base, to hold them on and to keep them well grounded. Now to get these buggers off you could just de solder the solder, but that requires a pretty hot iron and puts a lot of heat into the pickup which could short out coils. My way? I used a dremel to cut through the solder, worked like a charm.

Before:


Grind that solder down, and after


Now stuff starts to get more dangerous, now is time to remove the cover, there shouldn't be any screws (at least the poles that look like screws aren't screws and the four small brass screws on the bottoms hold the coils on) but there might be, everyone's pickups are different, and I for sure have no idea how EMG covers are stuck on there. Anyhow, I simply took a very small flat screwdriver and pryed in the edges (about where the solder was). As you can see in the picture after I had cut the solder, up there /\ I actually had started prying and it's kind of bent out. Anyhow, the main idea is to get the cover to come straight off, if you get it crooked it'll start to bind up and scrape wax, grab stuff, just generally make a mess and make it harder, so pull it off straight, alright? Other than that, it's pretty straight forward.

-3 Beginning Surgery

Alright, so now you're faced with two coils. Lets look at them.



Here is mine, and as you can see, (or as you may know if you read the uncovering part) mine were covered and potted, so I have a nice cover shaped wax casting . Unfortunately my 'coil tapping wire' is in there. So in the words of doc brown, "we may have to blast!" er, dig. Now, lets look at that second picture of the end of the pup. You can see the main wire running through the hole in the bottom of the chassis and up into the wax abyss. You can also see a white wire inside of the wax, in fact two white wires. Now, lets dig.
Last edited by LeviMan_2001 at Jul 20, 2010,
#2
-4 Finding The Connecting Wire

THIS IS THE TIME TO EXORCISE YOUR EXTREME BRAIN SURGEON LIKE CAUTION. UNLESS YOU'RE DR. FRANKENSTEIN, THEN USE EVEN MORE CAUTION.



Now lets talk about those little wires in there. You can see one wire is actually the white center lead from the shielded cable. THIS IS NOT THE ONE WE WANT. There's also probably a wire connecting to the shield of the cable. THIS IS NOT THE ONE WE WANT EITHER. We want that nice white one that came out in a loop. Your pickups probably won't pull out in such a nice pretty loop, I did a gibson goth explorer pup once (actually twice, as I did both neck and bridge) and the wire I wanted was actually underneath the one that connected to the main wires.

Anyhow, so what do we do with it now that we found the wire we think we want? Test. Then test it then test again. Grab your soldering iron and melt through the insulation until you can see a little bit of the wire. Now take your multimeter (if you don't have one then just go get one, really) and measure the resistance from that spot you just bared to both positive and negitive. It should be about half of the over all resistance to BOTH POSTITIVE AND NEGITIVE. if it reads 0 ohms to one side, you've got the wrong wire, put some tape on it and try again.

Speaking of buy a multimeters, look at my cheapo ghetto one, it was $4 at some cheap tools traveling tent sale thing (sorta like harbor freight or something). As you can see my leads both broke but JB Weld and a coat hanger came to the rescue! haha

Now, you've got that wire, you bared a small part of it and it has resistance (about 3-5k ohms in my case) to both sides. Congrats! That's the hard part done! Now you just need to solder a wire to it if you want a three conductor setup. Three conductors work fine for just coil taps. For more information about this or if you're still confused, look at the table I made down a ways

Here you can see my three conductor wiring, I just happened to have a piece of shielded cable laying around to use so I soldered the center of that up to the 'coil tap wire' and the shield to the pickup's case. Maybe it reduces noise or something I dunno. Oh and of course, always put a little tape on your connections, just so they don't short out. I use duct tape because electrical tape blows and comes apart in like five minutes.


-5a Four Conductor Wiring

Now say you want to continue on to a four conductor wiring. Now I haven't done this myself as it has been unnecessary for all applications I've done pickups for. (a coil tap wiring and a jimmy page setup) . The theory is quite simple though. You just need to cut that center tap wire and solder wires to each side you cut. There, four conductors! I'll tell you how this translates to Seymour Duncan wiring.

-5b Wire Color Table

Seymour|-| Your old ghetto pup

Green----|-| Your ground or shield
Black-----|-| Your old hot
Red-------|-| The wire that connects (with about 3-5k resistance or so) to your "green"
White-----|-| The wire that connects (with about 3-5k resistance or so) to your "black"

Oh and by the way, the three conductor setup is the equivelent of the red and white connected together.

-6 Finished!

And that's all folks! Now I won't cover coil tap wiring because that's a whole nother thing.
Now for finishing notes, put your covers back on if you had 'em. Now the thing is, your covers aren't soldered or waxed on any more. You should solder them back on and re-pot your pickups (that's been covered before, so I won't get into it) because now that you've broken the covers free, they rattle and are microphonic, it kind've sucks. That said, post below with any questions or comments to improve my bad writing and I'll try to keep up.
Last edited by LeviMan_2001 at Jul 20, 2010,
#5
Yeah, we already have a tut, also an image I drew a while back:

http://img541.imageshack.us/img541/5848/convertingto4conductorp.png

EDIT: you also mention something about EMG's, and I'd like to point out that their actives cannot be split in this manner. If you want to get a versatile one for both humbucker and single coil, you will have to go with the 81TW, the 89, or the 89R.

Their passives are already 5 wire although I haven't had a chance to use them to see if that is just normal 4 wires and a ground.


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RBY CYOA
Last edited by MonkeyLink07 at Jul 20, 2010,
#6
Good tut, perhaps you could merge the two tuts together into one super-tut? I personally use as many tuts as possible when doing work like this.
#7
+1 to what john said..

I was gonna post a link to that pink queens thread and suggest that the title should be changed to coil SPLIT, too


well done on the thread though. I did this to an old set of pickups I had lying around and it turned out pretty decent. nice work