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. 

Tools and General Materials Needed:

• Soldering iron (obviously) and Rosin Core Solder

• Needle Nose Pliers

• Electrical Tape

• Wire Strippers and/or Pocket Knife

• 3/8" drill bit

• Heat shrink tubing

Specific Materials Needed:

• Wire.  I 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.

• (4) DPDT (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......

• Capacitors:  On my Lester, I used Sprague Orange Drop caps for the tone grounds.  I got them from www.guitarpartsresource.com.  I used a 0.015mfd (microfarad) on the neck and a 0.022mfd on the bridge.  Stock Gibson values are usually 0.022mfd.

• Treble Bleed 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.....)

• Knob pointers 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).

• Start soldering.  Work in this order, basically from the control cavity's bottom up:

  • 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. 

• Desolder 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.

• Now finish 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.

That's it, 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 the bridge. 

• 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......

  Take a 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. 

  I'll also give you some tone descriptions here that will give you an indication whether your push/pulls are doing what they're supposed to be.

  Here are the tests that you should do:

  • All push/pulls "down": This should function totally like a normal Les Paul.  The toggle switch controls each pickup and when each pickup is off, its respective controls are negated.

   

  • 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.

   

  • Bridge Tone pot: Phase change.  Pulling this pot reverses the phase of the bridge pickup by swapping its ground and hot wires. 

    • This will only have effect when the main toggle is in the middle position because both pickups have to be on for it to change your tone.  The science of it is a little complicated, but basically since the pickups have a different phase from each other each one will only output the frequencies that the other one DOESN'T have because the duplicates are eliminated.

    • This will sound "nasally" or "honky" when done properly.  Think of the solo to "The Ocean" and a lot of Page's live stuff or even Peter Green's early stuff is out of phase.  In fact, JP is quoted as referring to this tone as "that Peter Green tone". 

    • You have to have the pickups' output balanced also.  So if you have their heights balanced correctly, you can do this with an equal ratio, i.e. both on 7, both on 8, both on 10, etc.  If not, you'll have to mess with your volumes and/or heights to really maximize this effect.

    • Controls with this switch activated will function normally.  However, as stated above volumes need to be in a delicate balance for this to work.   A minor adjustment to either volume control will result in the louder pickup taking over and dominating the overall tone. 

   

  • Neck Tone pot: Pickups in series.  This is a little higher output and does yield a different kind of tone.  It's actually a fairly complicated circuit as far as what controls what. 

    • When this is active, you'll need the toggle switch in the middle or rhythm position, and you'll use the neck volume and neck tone.

    • The bridge volume is negated and you'll get mostly nothing with the toggle in the bridge position. 

    • The bridge tone will be active when the toggle is in the middle position because even though the bridge volume has no signal going through it, the bridge tone still is in parallel with the output jack.