Reversing Pickup Polarity

How to Reverse Pickup Polarity, Part 1: Single Coil Pickups

Last Updated: April 14th, 2020

This is Part 1 of a 2-part series on reversing pickup polarity. This article focuses on Single Coil Pickups. For Humbuckers, see Part 2.

Needing to reverse your pickup’s phase is something you most likely never want to encounter, but it’s an essential skill to have. If you are reading this article, you most likely experienced the ‘Out of Phase’ tone:

On most guitars and styles of music, the out of phase tone is not desirable, but some people prefer it; a la Peter Green. If you do not prefer it, you may want to reverse the phase of one of your pickups to fix the problem. However, changing the phase of a pickup can be trickier than merely reversing the wires. More factors contribute to the overall phase of a guitar pickup.

In short: reversing the phase involves changing only one of the two attributes of the pickup:

  • Coil Direction
  • Magnetic Polarity

Let’s explore the subject in more detail!


PART 1: PICKUP POLARITY REFRESHER:

As stated in our previous article on the subject:

Pickup Polarity is the combination of the wind direction and the magnet polarity within the pickup.

Are the magnets in the pickup North Up, or South Up? Was the Pickup wound Clockwise or Counter-clockwise? To illustrate, let’s take a look at a Strat Pickup:

MAGNET POLARITY:

This pickup is South to Strings.
This pickup is North To Strings.

As you can see above, there are only two poles of a magnet: North and South. Most sets of pickups will have RW/RP pairs, so they cancel hum in the middle positions (think Strat or Tele). A Telecaster, for example, might have a South-to-Strings Bridge Pickup and a North-to-Strings Neck Pickup. If both pickups have opposite coil directions, the middle position is hum-canceling.

COIL DIRECTION:

The coil direction refers to the winding direction of the pickup. When you combine two opposite coil directions, you get a Reverse-Wound Pair (that’s where the RW comes from in RW / RP).

The pickup on the left features a coil that was wound clockwise from ground to hot, and the pickup on the right features a counter-clockwise coil.

WHAT IS “PHASE”?

“The simplest way to explain phase is one pickup is ‘pushing’ on the speaker, while the other pickup is ‘pulling’ on the speaker. Due to this, frequencies are cancelled out.”

Lindy Fralin

For pickups to be in-phase and hum canceling, they need opposite coil directions and opposite magnetic polarities (RW / RP). If you meet only one of those criteria, you will experience out of phase. For instance: if both pickups have the same coil direction but different magnetic polarities, your pickups will be out of phase. Out of phase pickups sound thin and weak (listen to the sound clip above).

It’s important to note: if your pickups are out of phase with each other, reversing the phase of one pickup will fix the problem.

Two pickups that have the same polarity (both wound the same and magnetized the same), are in phase, but not hum-canceling.

CAN YOU REVERSE THE PHASE?

Yes, and no. In some instances, you can quickly reverse the phase of a guitar pickup. In other situations, it is not possible to change the phase. Once you’ve determined which attribute is the problem, you can diagnose and see if changing the phase is possible. Again, all you need to do is change one of the pickups’ attributes. Let’s start by reversing the pickup’s leads:


PART 2: REVERSING THE PHASE OF A PICKUP

REVERSING THE LEADS:

If you think the easiest way to change the phase of a pickup is to flip the leads (black & white), you’d be right half of the time. Flipping the leads on Fender pickups like Stratocaster and Telecaster pickups are more difficult than working on Humbuckers (see our article on that subject here). When we wind a Strat pickup, like our Vintage Hot, the first wraps of the coil directly contact the magnets. Now, it’s true that coil wire has an insulation, and theoretically, that insulation will prevent the coil wire from making contact with the magnets, allowing you to reverse the leads.

However, the insulation is only 1/10,000″ thick and occasionally fails. In his wisdom, Leo Fender designed his pickups to have a fail-safe. If the insulation cracks, and the coil wire does make contact with the pole pieces, they instantly become grounded, instead of hot.

Reversing the coil direction of a pickup that has a shorted magnets will result in a plethora of noise you do not want. Therefore, upon request, we can apply tape to the magnets before winding to make sure the coil can be reversed at will.

Reversing the phase by flipping coils on a Strat or Tele pickup
Without Taped Magnets, Fender-style pickups cannot reverse polarity by swapping the leads.

SUMMARY ON FLIPPING LEADS:

  • Stratocaster and Telecaster pickups are notoriously difficult to flip the lead wires
  • It’s difficult to flip the leads due to the coil wire touching the bare magnets or pole pieces
  • Stratocaster and Telecaster pickups with Taped Magnets feature an easily reversible coil direction
  • The coil wire does not touch the magnet or pole piece on pickups with Plastic Bobbins (P90s, Humbuckers, Steel Pole 42s, Steel Pole 43s)
  • Plastic Bobbin pickups are easier to reverse the coil direction, so long as it has a separate shield from the coil wire (2-Conductor with Shield lead)

REVERSING MAGNET POLARITY:

Reversing the coil direction is only one part of the equation, and reversing your magnetic polarity is more difficult.

Strat & Tele Pickups:

Reversing the magnet polarity of a Strat or Tele pickup involves placing the pickup in a very strong magnetic field opposite to the polarity it currently has. It requires special equipment and knowledge to perform correctly.

This is not something you can do at home. Feel free to send the pickup to us, and we will re-magnetize the pickup for you. It only takes about a day or two in the shop, and is very inexpensive. Check the link below for further information.


In summary, it’s easier to reverse pickup phase with some models, and more difficult with others. Single coil pickups are notoriously difficult because they were not designed to have their phase reversed. Humbuckers are easier, but the job gets complicated when the humbucker has a cover installed.

There’s a lot that goes into reversing a pickup’s phase, and it can be difficult to wrap your head around it. If you have a question, leave it below! Until next time.

Written By:

Tyler Delsack

Tyler Delsack is the Manager of Fralin Pickups and spends his time editing and maintaining the website, designing graphics and ads, and making pickups. He's powered by Jazz Guitar, Vietnamese Food, Hiking, and Beer.

Author's Note: These blog posts are for educational and information purposes only. We do not offer custom wiring diagrams or wiring help or troubleshooting. For this, we recommend going to a local luthier or tech.

8 Comments

  1. Is taping the poles/magnets before winding undesirable in any way or type of installation? If not, I would think everyone would get the tape just to sort of bullet proof the pickup from shorting against the magnets over time. Does wax potting a pickup achieve the above mentioned protection from shorted windings?

    1. Hey Don,

      It might make the smallest difference in tone, but not one that can be heard easily. I would imagine moving the magnet wire away from the magnets 1/1000th of an inch darkens the pickup’s tone the slightest bit. Wax Potting does not remedy this problem but helps prevent it in the first place as it helps prevent corrosion. If you haven’t already, check out our article on wax potting.

  2. How might the problem play out on a Jazz bass? What might be involved in a change of polarity or phase for a Jazz, and what level of skill might I have to gain in order to work with stacked pots, coil taps, creating a schematic diagram from photos of a control plate and some of the other variables out here in the field? (Add in the variable of switching from a 10% overwind pickup to a stock wind pickup) How can I differentiate between a phase problem, coil polarity problem and/or component failure? Well, actually I know part of the answer to that, a couple of local community colleges have good electronics programs, I could get into one of those. . . Thanks.

  3. Tyler, thanks for the explanation. So, it means as long as the coil is not shorted to the magnets (pole pieces), you can flip the both leads to reverse the polarity of the pickup, right? I’ve read some comments on other gear forum, that you should ground “the start” of the coil to achieve slightly less noise operation, but you can also flip the leads if you want/need to reverse the polarity to solve a phase-out issue. Is this correct or should be avoided for preventing the case what you described happens?

    1. You can certainly try it without too much hassle. However, on a typical Strat or Tele pickup, there are anywhere between 80-100 turns of coil on the initial pass. It takes only one wire with cracked insulation to cause the problem previously described. As mentioned in the article, Strat and Tele pickups are notoriously difficult to reverse the phase.

  4. Could you elaborate on this? The coil wire is insulated, right?
    “When we wind a Strat pickup, like our Vintage Hot, the first wraps of the coil directly contact the magnets. We ground the magnets this way through the Black lead.”

    1. Hey Tak, thanks for reading, and great question – this needs further explaining.

      The coil itself does not ground out the magnets like the article reads. I’ll amend the article to reflect that. The insulation does separate the coil from the magnets. However, if you test 10 pickups in a row, you will find that one or two of them have a magnet that does short to the coil. In essence, the insulation has failed and the coil has contacted the wire. If the pickup is wired correctly, it’s not a problem because the shorted magnet connects to ground.

      That being said, if you reversed this pickup’s leads, all that noise would come through. It would sound similar to touching the tip of your guitar cord when it’s plugged into the amp.

      Does that clear it up?

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