There are a few variations on this out there. Here's the one I did
with some tips. I did it once as one of my first serious mods.
It worked, but it was a real ugly wiring job. I also bought short pots
first only to find out that I needed long shaft pots for the volume pots.
Like I said it was a pretty messy job so I decided to redo it.
Note that you must have
4-conductor humbuckers for this to work. I ordered parts and used
diagrams from www.guitarelectronics.com
for the first time around. I've also bought some parts from
www.stewmac.com when I redid this mod. I used 4 DPDT push/pull pots.
General Materials Needed:
used 22AWG solid core wire from Radioshack. You can get (3) 30' rolls
for like $5. The single core will really help you wire up the tiny
little terminals on the switch portion of the pots.
(double pole, double throw) potentiometers. Use 500kW
audio taper ones. I got them the cheapest from Stew-Mac but a lot of
places have them. If you're doing a Les Paul,
save yourself a little trouble and just order the long shaft ones so you
don't have any problem getting the threaded part of the shaft to come
through the top. You'll probably actually need the long shafts for the
volume pots but maybe not for the tone pots. However, you can always
just put a second nut on the shaft to space it down so that they don't stick
out too far. If you're wanting to do this with an SG, you'll
definitely want the short shaft ones and you still may not be able to get
them in your cavity and get the control plate back on. I didn't
actually try it in my SG but I measured with a small ruler and I know it was
going to be very close.
I'm not a huge fan of push/pull
pots. I like push/push pots a lot better but they haven't really
caught on for some reason and I don't think that I've ever seen a long-shaft
push/push. I dislike push/pulls because a) pushing something is really
fast and getting your fingers under the knob to pull is considerably slower,
and b) because when pulling I have both pulled the knob off of the shaft and
also pulled the shaft right out of the pot. Obviously, neither of
these happen with a simple spring loaded push of a button......
On my Lester, I used Sprague Orange Drop caps for the tone grounds. I
got them from
I used a 0.015mfd
(microfarad) on the neck and a 0.022mfd
on the bridge. Stock Gibson values are usually 0.022mfd.
Caps: I don't know if it's the taper of these pots or what, but these
get really dark when you barely touch the volume knobs. So I installed
a 1000pf (0.001mf) cap across the switch and hot legs of each volume pot.
This is great and helps a lot.
(See below for an update.....)
also called position indicators (optional). I like these but they're
obviously not required for the mod.
How to do
it (click for full size image):
The main rule of thumb here:
plan on this taking several hours if you're new at this stuff and a couple
if you're pretty good at it. It's going to take a long time and you're
probably going to screw up at least once. Plan on this!!!!!
Do one joint at
a time and be very patient and very careful. In general, plan which
wire you're going to do and cut more than what you'll need. Strip one
end of insulation, only usually about 1/8" of an inch. Place it and
solder it. Then locate the other end, cut it and strip it only as much
as you need. Remember, too much will look really sloppy and not enough
obviously won't work.
Make a template
for the pots on your guitar first. (You can see mine in the pics
below.) Pull the knobs off your guitar leaving the pot shafts sticking
up. Take a piece of cardboard around 5" square and just press it down
against the ends of the pot shafts. Drill or cut a 3/8" hole in the
cardboard where the impressions are and mark them as to which pot goes there
(NV, NT, BV, BT). You'll put the new pots through here shortly.
Take your (4)
new pots and put them into your template. Put a couple nuts on the
other side to hold them on. Put them in so that each pickup's volume
pot is facing its tone pot (see below).
soldering. Work in this order, basically from the control cavity's
Ground the pot
terminals. Each pot has one pot terminal that goes to ground, but you
can just bend them up on a DPDT pot like a regular one, so you'll have to
run a short jumper to the pot casing (don't use the case around the switch
terminals, use the casing around the pot itself). When doing this,
think about where on the case you're going to put the loop wire that will
connect all of them together and ground them. I took the all the
jumper wires "up", or towards the strings and bridge.
Ground the pot
cases. For this, I ran a single piece of wire around them on the
"bottom" side of the pots. Strip one end and solder it. Then cut
and push the insulation back about 1/4" and solder it. Repeat around
the 4 pots.
Put the caps in
the pot terminals. I installed them with the 50's wiring mod.
There's a lot of material out there about what this does. Check out my
page on this here. Note in
the picture below that I didn't put any heat shrink tubing on the leads of
the cap. I should have done this and I'm going to go back and do it.
I used Orange Drop caps and if the leads touch the rest of the cap, they can
short across themselves and you'll get a "no treble, tone knob on 0" type
sound. I need to go back and insulate these.
Now you're to
it. Just pick a pot and start from there. Insulate any loose
joints, like the one three way joint that's needed. Twist all the
leads together, add some solder to hold them, then heat shrink (or
electrical tape) over the exposed wires.
So once you've
got the circuit done on your template. Go over it one more time and
make sure it's right. In general, it ought to look like this:
Now it's time
to take apart the old circuit in your guitar. Before you desolder, I'd
stick a piece of masking tape around each harness saying what it is, B for
Bridge, N for Neck, and SW for Switch.
everything and pull your old pots out of there. "Pretty up" your
pickup and switch wires to get them ready.
Fit the pots
down into your guitar. Drop them in and make sure that you have the
right amount of pot shaft exposed on each place. You'll probably need
to have a second nut on the inside of the cavity to space them "down".
I'd put about 4-5 threads showing outside the guitar.
it..... Make sure that nothing's touching anything else that shouldn't
be. Check your grounding. The ground side of the jack needs to
be connected to one pot and they all need to be connected to each other.
Plus the ground cable from the bridge needs to be grounded also. Plus
if your braids from your switch and pickups are shielded, the bare wire from
those braids need to be grounded also.
Before you do
final tightening on the nuts and put the cover and knobs back on, plug her
into your amp and do a quick test run. Don't button everything up
until you know it's right.
you're done. It's pretty cool!
6/18/2007 Update - Initially I
found that this circuit gets very dark as you drop the volume. So I
installed a cap as part of a treble bleed circuit. I used a 0.001uf
cap (1000pf) but I found that it wasn't doing the job. I did some more
research and found that most people use a resistor in parallel with the
resistor. Most folks use caps from 680pf to 1000pf (0.00068uf to
0.001uf) along with resistors from 100kOhm - 300kOhm. Mixing the two
components is more complicated than I'm going to make it here, but in
general, a brighter and consequently thinner sound comes from a lower value
cap and a lower value resistor. A darker sound (with the circuit
having less effect) with a higher value cap and a higher value resistor.
I've found this guitar to be a little dark so I even pushed the values a
little further. It's great on the treble pickup, and it works on the
neck, but it seems to be having a little less effect. It's still a
great improvement but it seems to have less of an effect on the neck than
10/04/2007 Update - So I
finally got around to playing with the treble bleed circuit on the neck
pickup. Some folks do this with only a capacitor instead of a resistor
in series with a cap. With the old cap I was using (I think 560pf) I
removed the resistor and installed a pair of leads with alligator clips and
used a pot to look for the sweet spot. I found that the higher value
in resistance, the better it did, but that just completely messed up the
taper on the actual volume pot. So I had a constant volume from 2-10.
Anyway, so I gave up on the resistor and just changed to a cap with a value
much higher. I think what I had was a 0.0018uf cap. This worked
much better. I might have even gone a little higher, but I didn't have
any caps in the right range. So it's staying like this for now.
6/15/2008 Update - It occurred
to me while helping someone wire this up for themselves: there's not a whole
lot of documentation out there about USING this mod and what exactly each
switch does electrically and how it will affect the “normal” controls. So
here it is......
small screwdriver or metal ruler or something to tap on your pickups to
verify what is active and inactive. Turn all your effects off and maybe
raise the volume on your amp a little. When checking, I tap lightly right
on the adjustable pole pieces to see if the pickup is on. Depending on
what you're checking, I may also swell the appropriate pots too.
give you some tone descriptions here that will give you an indication
whether your push/pulls are doing what they're supposed to be.
the tests that you should do:
Coil taps (Volume Controls): These individually shunt half of each
pickup to ground, effectively making it a single coil. Check each
position of the main toggle switch. Each one should still sound like its
own voice, but a little thinner. Otherwise, each of these should still
function like a normal LP with the tone and volume controls as expected.