From the various mods I've made to my Epiphone Dot's humbucker wiring, I now realize what I should have done to start with! So I've put together a diagram (attached below) detailing what I'm calling DVM's "Full Boat" Dual Humbucker Wiring Mod. The diagram shows a comprehensive overhaul of the stock wiring to add a large number of new tonal options to a 2-humbucker guitar equipped with separate volume and tone controls for each pickup. This mod has the additional advantages of (1) not removing or altering the three stock tones, and (2) not changing the appearance of the guitar (i.e. no drilling/new holes, extra switches, etc.).
I do not mean to imply that any of this constitutes "original thinking" on my part! I've just taken several well-known mods and tried to integrate them together in a logical way and represent them in a clear and well-labeled diagram. Hopefully, this will accomplish that end. If you're familar with the "Jimmy Page" Les Paul mod, you'll notice that this is very similar. The main difference is that it substitutes series/parallel switching on the individual humbuckers for the series/coil-cut switch the Page mod employs.
In a nutshell, the mod involves replacing all four of the stock control pots with "push-pull" pots fitted with 6-contact double-pole/double throw (DPDT) switches. It requires that both humbuckers be of the 4-conductor variety. While many "aftermarket" humbuckers sold by outfits like Seymour Duncan and DiMarzio are of this type, the stock humbuckers that come in most guitars are 2-conductor and will not work with this mod. So you may be looking at a pickup upgrade to be able to do this, which obviously raises the cost of admission substantially! If you don't need new p'ups, you can do this for the price of 4 push-pull pots ($40 or so) plus whatever wiring and soldering supplies you need. Pretty cheap for the tonal benefits that will be reaped!
One other possible expense I should mention--for this project, you should definitely have a digital multimeter available to check continuity and troubleshoot problems. I picked up a cheap one at Radio Shack for $20 that handles the job nicely.
When completed, the "Full Boat" mod gives you the following capabilities:
- Run either humbucker with the two coils in series (stock) or in parallel (a brighter, thinner tone much like a single coil, but still hum-cancelling).
- Run the bridge pickup magnetically out-of-phase with the neck, giving an interesting hollow, somewhat nasal tone. Sometimes referred to as the "Peter Green mod".
- Run the bridge and neck pickups in series with each other, vs. in parallel, which is what the middle position of the 3-way pickup selector toggle gives on most stock dual-humbucker guitars. This gives a bigger, fatter sound. I refer to this as the "megabucker mod", because it essentially turns the two humbuckers into one big 4-coil 'bucker.
When you look at the possible combinations of these various options, there are 20 unique combinations, though some are only very subtly different from each other, and a few aren't very useful. But even if you found only 3 new settings that you really like, you've just doubled your dual-humbucker guitar's tonal flexibility. And I'll bet there will be a lot more than 3 you'll find useful!
Additionally, the diagram shows the contacts on the volume pots for the pickup output signal and the wire to the 3-way pickup selector toggle reversed from the stock wiring. Doing this will make the two volume controls independent when the toggle is in the dual-pickup (middle) position. With stock Gibson-style wiring, turning down either volume pot while in dual-pickup mode will reduce the volume of both pickups simultaneously. Making them independent gives you mixing control over the two p'ups, a nice tonal advantage, IMO. I've really never understood why Gibson wires them the other way!
One last, important point: Let me give fair warning right now--this mod involves a LOT of soldering work! If you have no previous soldering experience, this would not be the project to learn on! But if you're comfortable with your soldering skills and have a mind to turn your Les Paul or other 2-humbucker guitar into a magical multi-tonal music machine, this mod's for you!!
EDIT: Here's another way to do the "Full Boat", with coil-cutting for the two humbuckers substituted for the series/parallel switching. It's much easier to wire the two push-pulls on the volume pots, and I find that the coil-cut and parallel coil wiring both sound very similar. You'll sacrifice the pickup's humbucking property when you coil-cut, but the added noise is pretty negligible.