Fralin Pickups - How Coil Splitting Works

How Does Coil-Splitting Work?

Last Updated: April 22nd, 2020

Coil Splitting is a simple, usable way to add another dimension of tone to your guitar. You can essentially double your tone, with a flip (or pull) of a switch. You can use this to clean up a beefy humbucker or get your tone to “cut through” a lot more. If you want to understand what’s going on when you split your humbucker, read on!

THE BASICS:

A Humbucker‘s two coils are wired In Series. This means that the output of one coil is entering another coil. Series wiring is what makes a humbucker sound so loud and strong. Humbuckers have a darker, beefier tonal quality to them – but what if you want Single Coil clarity? Enter Coil Splitting:

Coil Splitting involves changing where your humbucker’s leads go. Essentially, Coil Splitting involves connecting both leads of the Slug Coil to ground, essentially canceling out the coil. Let’s take look at how a regular Humbucker is wired:


NORMAL HUMBUCKER WIRING:

Normal Fralin Pickups Humbucker Wiring
Standard Fralin Pickups Humbucker Wiring

Let’s look at the above image. As you can see, a normal humbucker is wired by connecting the Outside Leads of each coil together, and sending the Slug Inside Lead to ground, and the Screw Inside Lead to the switch (hot).

LEADS:

Note that you need to have either 3-Conductor Wiring or 4-Conductor Wiring to split a humbucker. These conductors have each coil it’s separate output, all the way down the lead. If you have a humbucker wired with Gibson lead, your humbucker is already wired like this. There’s no way to split the humbucker with a Gibson Lead.


SPLIT HUMBUCKER WIRING:

As stated earlier, when you split a humbucker, you’re rewiring the leads of the coils. Here’s what your humbucker looks like when it’s split:

Split Humbucker Wiring
Split Humbucker Wiring

Two things have happened:

  1. You’ve connected the Red Lead of the Slug Coil to ground. As the Black lead of the Slug Coil already connects to ground, the entire coil connects to ground.
  2. You’ve also connected the Green Lead of the Screw Coil to ground. This allows the Screw Coil to remain functional.

HOW IT WORKS:

Using our Push-Pull Pot, we’ve connected out Red and Green leads to ground when we pull up. Here’s what’s happening under the hood:

Normal Humbucker Wiring - Coil Splitting Operation

As you can see, when the push-pull pot is in the down position, the Red and Green wires are not connected to anything else – the humbucker is in full-functioning mode.

What happens when you coil split a humbucker

When you Pull Up: Both the Red and Green lead now connect to a ground jumper to the casing of the pot, sending the finishes to the ground as illustrated above.


COIL SPLITTING VARIATIONS:

Depending on the lead you have, and the set-up you want, there are a few options you can perform. On a 3-Conductor Lead, Red refers to the Tap (coil finishes). On a 4-Conductor Lead, You have Red and Green As the coil finishes.

Also, depending on your guitar, you can coil tap two humbuckers at once, with one push-pull pot. Here are the variations listed below:

Coil Splitting Options

Let’s look at the bottom two images. You can split two humbuckers simultaneously by the same push-pull pot. As soon as you pull up, both humbuckers split at the same time. If you want independent control over your humbuckers, you need to use two separate push-pull pots, one for each humbucker.

Note: In the first two examples above, we’re using the “left” side of the switch. It really doesn’t matter which side you use – as long as the Ground connection is above it.


Well, that’s all for now. Stay tuned next month for our next article on Resistors in guitars, and Happy New Year!

21 Comments

  1. Don,
    The white conductor(hot) is the beginning of the winding that goes round and round the screw bobbin.
    The electrons travel through all those windings, creating an electromagnet and the end of that winding gets grounded, completing the circuit. It’s the same as a single coil with hot connected to the beginning of the winding and the end of the winding connected to ground.
    So, you either have hot going through the screw section and continuing on through the slug sectIon finally to ground(full humbucking), or you have hot only going through the screw section to ground(single coil).

  2. HSH with 5 way switch, tone control w/ push/pull coil split, 3 conductor pickups. Positions 2 thru 5 function normally, but Position 1 Bridge Humbucker suddenly dropped to almost no output volume. Coil split on Position 1 has normal volume. Tip/ring shows open on Position 1 when coil split pushed down. All wiring solders look and feel solid. Resistance shown betwixt red and white leads from bridge humbucker at switch solders. I’m scratching my head?

    1. Hey Merrel, how are you wiring the bridge? Is it ours? If so, our color codes are here. It could be the shield got too hot and melted through the jacketing of your White wire, creating a short. Can you visually inspect the white wire connection?

  3. Hi Tyler,

    I have a Duncan humbucker in which the red and white leads are typically taped together to maintain the full humbucking mode. For my project I want to ground one of the coils to make it a single coil when I pull up the push-pull tone pot I bought from you great folks at LF. In your website article on “5 Powerful Ways to Coil Split Your Humbucker”, it is the switch pictured on the left, the black one. I understand that lug 1 gets soldered to the casing to provide the ground feature, but I’m not sure what I do with the other leads. Does one of the coil tap wires go to C1, and the other go to C2?

    Thanks
    Doug

    1. Hey Doug,

      If your Duncan has the White and Red leads taped / soldered together, then this is your “center tap” and allows you to split the coil. You do not separate the leads, just solder both to the Push Pull pot. My diagram shows a single Red lead. Imagine your two wires as a single wire. Let me know if you have any questions!

  4. Hi Tyler, I am electronically challenged (gives me a headache), but fine with the ‘mechanical’ side of guitar repairs. I can follow a wiring diagram and solder competently. In your quote at the very beginning of the article you state”Coil Splitting involves connecting both leads of the Slug Coil to ground, essentially canceling out the coil. ”

    But In the ground – sending push pull diagram, it shows the red and green leads (one from the slug coil, one from the screw coil) , not the red and the black from the slug, i.e. (in my mind) to send the slug to ground to cancel it out and leave the screw coil active. However if the green actually does go there as shown, how do you get any sound out of the screw coil if its cancelled by going to ground with the slug?
    I have a headache….
    Thanks,
    Don

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