Wiring Mod for Dual Humbucker / Only One 4-Conductor

[duhvoodooman]

If you have a dual humbucker guitar with one 4-conductor 'bucker and one that's only single conductor/braided shield, then the "Full Boat" wiring mod isn't an option. My Epi LP standard has exactly this configuration, with a 4-conductor Duncan Pearly Gates at the bridge position and a single-conductor/braided shield Duncan '59 at the neck. But you can still get a bunch of useful new tones by installing three double-pole, double-throw push-pull pots wired per the following diagram. I did this over the weekend, and it works great:

You'll also notice that, rather than wiring the bridge pickup for series/parallel switching, I opted to go with a stud coil-cut instead. I did this because I already have my Dot wired for series/parallel switching and wanted to try something different on the LP. For grins, I temporarily hard-wired it up both ways and compared the two; the stud coil-cut has a bit more treble and bite to it, though the two tones are awfully close. The controls cavity in my LP is very well shielded, so hum really wasn't an issue running in single-coil mode. The coil-cut also has the advantage of being a lot simpler to wire than series/parallel. However, if you'd prefer the series/parallel option, just refer to the "Full Boat" diagram for that wiring configuration.

Anyway, I'm really enjoying the new tones on tap for my LP. The coil-cut twangs, the "megabucker" thunders, and the phase switch has that cool hollow, nasal sound, reminiscent of a wah pedal left halfway down. I'll try to get a clip or two posted in the next couple of days....

 

[Justaguyin_nc]

DVM, I will be trying to put 2 four wire humbuckers into a guitar with one volume one tone and a 3-way switch... do you have a diagram for this? best setup in your opinion? with caps etc..

 

[Justaguyin_nc]

Im sorry..no sooner I ask the question I find the answer.. Think the OLP needs a DiMarzio 3-Position On/On/On DPDT Mini Switch to make this setup compared to stock.. have yet to see it.. just reading the difference from the musicman versions.. any additions you might add to this?

 

[duhvoodooman]

Im sorry..no sooner I ask the question I find the answer.. Think the OLP needs a DiMarzio 3-Position On/On/On DPDT Mini Switch to make this setup compared to stock.. have yet to see it.. just reading the difference from the musicman versions.. any additions you might add to this?

This option is certainly doable with the use of the appropriate switch, but it wouldn't be my first choice. Unless I'm missing something, all it's adding is putting the two stud coils together in parallel. The normal middle position on a dual-humbucker 3-way switch is both full humbuckers in parallel. I'm sure the tone is somewhat different, but it seems to me to be operating inside the "tonal box" that the guitar already has. I think some other mods would make the box bigger, so to speak.

The Seymour Duncan site has a great schematics page with about a zillion different combos. They show several iterations on your guitar's "2H-1V-1T-3-Way" configuration, including using push-pull pots for coil-cutting and phase switching. Push-pulls are the way to go, IMO.

The main drawback with your guitar's set-up is that you can only install two push-pull pots, replacing your existing volume and tone pots. So if you want more than two of the different wiring mods, you'd have to put in an extra toggle or switch, altering the guitar's stock appearance.

If you want to just use the two push-pulls, then you have to make a choice on which switching options you want. I definitely recommend doing a coil-cut switch for both pickups, because you can wire both to a single DPDT push-pull. The only downside is that you can't coil-cut them independently--you get both 'buckers coil-cut when you lift the switch. Really not much of a disadvantage! How often would you run in dual pickup mode with only one 'bucker coil-cut?

So if you go with the dual coil-cut, then you just need to decide between the "megabucker" series switch or the phase switch for the 2nd push-pull. (I wouldn't recommend the series/parallel switch, since parallel and coil-cut sound quite similar.) Depends upon whether you want the ultra-fat series tone or the hollow, nasal "Peter Green" out-of-phase sound. Tough choice--I like 'em both.

Using one of the Duncan schematics, I roughed out a couple of diagrams of my own. Both have the dual coil-cut switch, but one combines it with the megabucker series switch and the other with the phase switch. Here are the links:

Dual Coil-cut + Megabucker Mod

Dual Coil-cut + Phase Switch

 

[Justaguyin_nc]

So if you go with the dual coil-cut, then you just need to decide between the "megabucker" series switch or the phase switch for the 2nd push-pull. (I wouldn't recommend the series/parallel switch, since parallel and coil-cut sound quite similar.) Depends upon whether you want the ultra-fat series tone or the hollow, nasal "Peter Green" out-of-phase sound. Tough choice--I like 'em both.

Using one of the Duncan schematics, I roughed out a couple of diagrams of my own. Both have the dual coil-cut switch, but one combines it with the megabucker series switch and the other with the phase switch.

Thanks for your time DVM.. I have both gifs saved and now will have a bit of time to think on which way to go... will let you know how it turns out, your a treasure to the forum..