I'm back, and I've got pickup troubles...

[McGee]

I've got a set of Seymour Duncan Seth Lover pickups in my MC-1. I decided
to try my hand at modifying my wiring to add a coil tap. I bought a new
volume pot with the push pull deal, and got started. As many of you might
already know, there are 2 configurations of Seth Lovers available. They
make a four wire, and a two wire version (for that real snooty, real vintage
thing). Wouldn't you know it, I've got the two wire version. Can I modify
the pickup, or would I need a new one? If I can modify my existing PU, can
you recomend some real good websights for doing the research? I'm pretty
good with a soldering iron, but I need laymans terms. I'm hoping to find
some illustrations or something that will show me how I'm going to have to
modify the pickup.
Someday I'll enroll in that electronics course. No, really, I will.
Thanks,
Michael

[krelnarb]

Ooooh, I would not attempt a coil tap. Not without first practicing on a junk pickup, and even then. Having converted a few pickups from 2 wire to 4 wire (not the same as a tap) I still would not try a tap.

I'm not familiar with that pickup of yours but I assume it's a humbucker (2 coils) Each coil has 2 wires, the inside of the coil winding and the outside. In a 2 wire pickup a wire from each coil is connected to each other, connected out of phase. In a 4 wire pickup the 2 wires are all brought out of the pickup so all the serial / parallel, in / out of phase tricks can be done with a switch.

A true coil tap comes from somewhere in the middle of the coil. Say you have a coil that's 3000 winds (a hypothetical pickup), let's say around wind 1450 you want to put the tap. You would have to unwrap 1550 wind of the coil. Sound fun? I thought not. Add to this there's no way of knowing what it'll sound like with out massive amounts of R&D.

What you may want is a 4 wire pickup. If you have disassembled the pickup you will see 2 tiny hair like wires from each coil, 2 of these will be connected as I mentioned above. These are the ones you want to connect your other new wires to. Very delicate and easy to destroy.

Having successfully converted a few pickups, I have also killed a few pickups. It's very sad. If you like your pickup and paid good money for it ($100 + ?) I would not try and modify it. If it's not what you what sell it and get the right one. If your curious by all means find a junk pickup to tear apart (the best way to learn.)

Try a search on "guitar pickup wiring"

Best of luck
k

[McGee]

Here's what a cat from another forum told me:


Hey dude-

Where are you located? Maybe you can hook up with someone who can help you.

I haven't opened up that particular pickup but I know it's not a potted
pickup which is the good news. I have another unpotted PAF-style pickup
that I have taken apart and it appears that they have joined the slug coil
winding with the screw coil winding by means of attaching a 28 or so gauge
wire to the thing under the wrap, then bring it out as if it were a 4-wire
pickup, and soldering the two extra wires together and putting a little
piece of electrical tape over the joint. If this is the way yours are
made, then it's as simple as pulling the tape off, unsoldering the joint
and soldering on two more wires to come out of the pickup. If you're not
so snooty then you could get a four-conductor shielded cable from someone
like Stew-Mac and solder it in place of the existing 4-conductor cable,
which would get all four wires in the (probably unnecessary) shield.

So the construction of the pickup is like this (once you get the cover off,
and I don't know how that's affixed on a Seth Lover... on my Golden 50's
they're soldered on with a heavy bead of solder):

there are four little screws in the baseplate of the pickup, two in each
coil (these are usually #2 sheet metal screws with a phillips pan head,
about 3/8" long). If you remove these screws, then the coils will come off
of the base plate. On most pickups, the screws in the pole piece places on
the screw coil will also be tapped into the base plate and you need to
remove them to get the pickup coils completely free of the base plate.

Once you get the coils off of the base plate you should be able to see how
the wires are terminated. There are two coils, each with one winding so
each coil has two ends of the winding. They're in series, so one end of
each of them is connected together, and the other end of each of them
comprises one of the current two conductors of the pickup. You must
separate this wire junction and wire in separate wires from each end of
each pickup. I suggest you are careful to use the same color wire for each
one as Seymour Duncan does, or some other common standard. Check out
Stew-mac's tech pages for info on exactly how they are wired.

Once you get the new wires soldered on then it's a piece of cake. Most
humbuckers I've seen have a little strain relief screwed on the bottom of
the base plate and this is really a dire necessity for installation without
damaging the pickup, so be sure and route all four of the new wires through it.

You can probably find a better small-shop kind of guitar shop with a good
electric guitar tech and have them do this mod for you for relatively
little money. I'd think most guitar techs would be able to do the whole
job, including the coil tap and the pickup mods and all, in like 1-2 hours
of labor.

I've noticed that the Seth Lover pickups get pretty penny on ebay, so you
might also be able to just sell those and buy a set of four-conductor
pickups. They will likely sound at least a LITTLE different, since those
pickups are designed to be varied just like the originals.

If you can find someone who has monkeyed with pickups much before to help
you, then that's the way to go. I'd do it for you if you were local. In
fact, if you pull the pickups, box them up & send them my way I would be
happy to do this for you for nuttin'. I'll be pickup hacking anyway in
about a week or so, so it'd be pretty easy to work in while the soldering
iron is hot. It's easy stuff to do, I've done it before.

Later-

[McGee]

And, Here is my latest "Problem"...


Thank you very much Mr. Karnes! I got it (sort of). I was on vacation last
week, and went home to New Jersey. The long drive with no stops put a real
strain on my back, and the next morning when I unpacked my Mark IV, I felt
my spine crunch. Very sucky! I was unable to haul my gear around to play
with old friends (not to mention the pain kept me out of the mood to play).
I figured that with a week off, (and barely being able to move) it was a
good time to rewire my axe. My father is much better with elecricity than I
am so I bought his help with a few homebrews.
The pickup construction was exactly as you had said. We wired an extra wire
from the joint in the pickup and put the PU back together. We wired the new
pot the same as the old. The new one has two banks of three connections.
The middle was common, and top and bottom were selected by the pull/push.
We cut the origonal wire from the pickup to the three position selector
switch. We soldered the input of the selector switch to the middle
terminal. The origonal wire from the pickup that we cut was soldered to the
bottom terminal. Our new wire from the joining of the coils went to the top
terminal. In the down position everything is as it was. In the up position
our new wire, spliced into the joining of the coils, went to where the old
wire terminated. Time to test it.
It worked. So far we had only messed with the neck pickup. I had the
choice of Bridge, Both, Neck, and Neck Tapped. I should have checked to see
if I could have had both with the neck tapped, but I didn't think of it. I
was astounded, and pleased with myself.
I got home a day ago, and decided to use my new rewiring skills to attack
the bridge pickup. I repeated the same procedure using the second bank of
terminals. I now have the Neck (split, tapped) and the Bridge (split,
tapped), but funny thing...
In the middle position (which should have both pickups active) I get
nothing. There is absolutely no output. I'm not sure that this is bad
since I kind of like having a kill switch on the body, and I do have four
pickup combinations to choose from instead of the three that were stock, but
this was not my expected outcome, and I don't yet know where I went "wrong".
Can someone tell me why the middle position on my pickup selector does not
have an output? I can't see a single change when I've got the pot in the
down position, everything looks to go to the same place that it used to, but
now nothing comes out.
Thanks a lot,
Michael

[McGee]

In case anyone's interested, I got it! The shielding on the wire I cut was not grounded after the push/pull pot. I grounded it last night, and now I have 6 different pickup combinations. I am very pleased.
Peace,
McGee