Hello and welcome back to “Mod Garage." The auto-split mod can help you avoid a common problem when using a humbucker together with the typical single-coil pickups in a Stratocaster. As you know, the H-S-S configuration (humbucker in the bridge position and two traditional single coils in the middle and neck positions) was introduced in the '80s with the superstrats, and is still very popular today. You can also find Strats with a H-S-H or even H-H-H configuration, but the H-S-S is still the most common.
Humbuckers usually have a lot more output compared to traditional Strat single-coil pickups—in other words, they're louder. As long as you use the bridge humbucker or the two single coils alone, everything is fine. The humbucker provides a hot output signal to easily drive your amp into saturation (which is exactly why it's there) and the middle and neck positions give you the traditional Strat sounds we all love so much, as well as the in-between position of middle and neck pickup together. The problem occurs when you use the bridge humbucker together with the middle pickup. Instead of the famous in-between sound we all know from our Dire Straits, Chris Rea and Eric Clapton records, you'll receive a loud tone, not much different from the bridge humbucker alone.
The solution for this is very simple: split the bridge humbucker to make it a single-coil pickup. For this, you need a humbucker with a four-conductor cable, so you have unlimited access to both coils, giving you the ability to shut one of them down. You can use a push/ pull or push/push pot for this, but a little 2PDT toggle switch works well, too. I'll stick with the basics for now, since I don´t want to turn this into a column about coil splitting. We'll do that in a future installment.
 Wiring diagram courtesy of Seymour Duncan Pickups and used by permission. Seymour Duncan and the stylized S are registered trademarks of Seymour Duncan Pickups, with which Premier Guitar magazine is not affiliated. |
A lot of humbuckers sound great when used as full humbuckers, but not very good when shutting down one of the coils. On the other hand, there are some that sound great when split (e.g. Seymour Duncan SH-3 “StagMag"), but not so powerful when used as a full humbucker. It´s always a compromise, and many players don´t need coil splitting, since the single-coil sounds are often not worth it. So, this is the point where the “auto-split" mod can help you.
Auto-split just means that when you have the 5-way switch in the middle/bridge position, you'll only be getting one coil of the bridge pickup, rather than the full humbucker. It's supposed to be closer to the traditional Strat “notch tone" than having the full bridge humbucker active. In the bridge position, you still have the full humbucker active, so this mod can give you the best of both worlds.
Let's Get Started
To start, you can download the standard Strat wiring scheme directly from the Seymour Duncan website to get a better understanding of the differences compared to the autosplit mod. Here's the Strat wiring with the auto-split mod performed:
As you can see, the black wire from the humbucker goes to the normal input lug for the bridge pickup, the red and white wires are soldered together to the lug of the output stage and green together with the bare wire are going to ground. Keep in mind that these are the colors Seymour Duncan uses for their humbuckers. Other companies use different colors, and you need a chart to translate those colors. For an overview, you can use the chart from Seymour Duncan: seymourduncan.com/support
For a deeper look, I highly recommend this one: guitarelectronics.com
If you're more experienced, you can also use a DMM to verify the colors, but a color chart is always a good starting point. For a better understanding, it's crucial to know what the colors mean and what they correspond to. Humbuckers have two coils, looking like two single-coil pickups in one package. The bottom coil is always the coil with the adjustable screws, and it's named “South." The coil on top is the one with the non-adjustable slugs and is called “North." Each coil has a start and an end. So, using the Seymour Duncan colors, we have:
Black = North Start (hot output) / White = North Finish / Red = South Start / Green = South Finish / bare wire = Ground
With this knowledge and the color charts above, it should be easy to do the autosplit mod with any given humbucker. We'll talk about this subject again, and of course dip in deeper, when we switch over to Les Paul, 335 and SG mods. That's it! I hope you find this mod useful, giving you the best of both worlds: powerful humbucker sounds from the bridge position side by side with the traditional Strat “notch tone" with the bridge and middle pickup together (aka the “in-between" position). Stay tuned for more Strat mods coming next month. Until then, keep on modding!
Dirk Wacker
Dirk Wacker lives in Germany and has been addicted to all kinds of guitars since the age of five. He is fascinated by anything that has something to do with old Fender guitars and amps. He hates short scales and Telecaster neck pickups, but loves twang. In his spare time he plays country, rockabilly, surf and Nashville styles in two bands, works as a studio musician for a local studio and writes for several guitar mags. He is also a hardcore DIY guy for guitars, amps and stompboxes and runs an extensive webpage (singlecoil.com) about these things.