We’ve explored pickup phase and polarity over the years in Mod Garage, and now it’s time to bring all the parameters together so you can successfully combine single-coils from different manufacturers in one guitar without creating unwanted sonic issues.

It’s common to mix pickup brands, and as long as you use each pickup alone, all is good. The fun begins when you combine two or more pickups without knowing their magnetic polarity and winding direction. Odds are you’ll accidentally create an out-of-phase pickup ensemble. You’ll know it when you hear it: Out-of-phase pickups sound shrill and thin. (Some players want this option when using two pickups, but we’re addressing an unintentional out-of-phase pairing.) To avoid this, you need to know the pickups’ magnetic polarity and winding direction before buying and installing them. The easiest way to determine this is to scour the spec sheets or contact the respective pickup manufacturers. (We also explored how to suss this out yourself using a compass and DIY phase-testing unit. If you’re an intrepid modder, check out “What’s the Deal with Pickup Polarity?,” “Build a Pickup Phase Tester, Part 1,” and “Build a Pickup Phase Tester, Part 2.”)

When you want to combine pickups, there are four golden rules regarding winding direction and polarity:

Rule 1. Opposite winding direction + opposite polarity = in phase with hum cancelling.
Rule 2. Identical winding direction + identical polarity = in phase, no hum cancelling.
Rule 3. Identical winding direction + opposite polarity = out of phase, no hum cancelling.
Rule 4. Opposite winding direction + identical polarity = out of phase, no hum cancelling.

This brings us to a phase/polarity “traffic-light” table that shows what happens with all possible combinations of two pickups. (In the columns indicating winding direction, CW means clockwise, CCW is counter-clockwise.)

Go green. The green combinations are typically described as “reverse wound/reverse polarity” (RWRP), a scheme designed to yield a hum-cancelling effect when combining two single-coils. A modern Stratocaster’s middle pickup is often RWRP in relation to the neck and bridge pickups, so when you combine middle with neck or bridge single-coils, you also engage the hum-cancelling effect. In this dual-pickup setting, the two single-coils work as a kind of humbucker, only with the two coils far away from each other, rather than side by side as on a standard humbucker. Because of this distance, the hum cancelling is not as effective as a true humbucker, but it’s still pretty good.

A modern Stratocaster’s middle pickup is often RWRP in relation to the neck and bridge pickups, so when you combine middle with neck or bridge single-coils, you also engage the hum-cancelling effect.

Mellow yellow. The yellow combinations are also desirable and often found on vintage-inspired Stratocasters (and, of course, true vintage Strats) with a non-RWRP middle pickup. Many players prefer this old-school approach because it offers more high-end fidelity and thus more “quack” in the dual-pickup positions. The downside? No humbucking effect, so these positions can produce hum and noise.

Stop! The red combinations yield out-of-phase sounds—exactly what most players do not want.

This table will help you plan ahead and avoid trouble, but what if you already have two pickups that are out of phase with each other when combined? For starters, don’t panic! Follow these three guidelines and you’ll have a 50/50 chance of saving the situation:

1. Determine each pickup’s magnetic polarity and winding direction and then use the above traffic light table to see what disaster category you’re in.

2. If you need to reverse a pickup’s winding direction, in most cases this is simply a matter of reversing the pickup’s two wires—the black one becomes hot and the white wire goes to ground. But make sure the ground wire (usually the black one) is not connected to any grounded metal part on the pickup (aka “grounded shielding”). On Teles, the black ground wire is typically connected to the bridge pickup’s metal baseplate or the neck pickup’s metal cover. If that’s the case, you’ll need to break this connection and then install a third, dedicated ground wire that’s always connected to ground, no matter what you’re doing with the original black wire.

3. Alas, changing a pickup’s magnetic polarity is not easy—only a few pickups are designed to remove and replace the magnets. For all other pickups: Don’t try this on your own! Chances are you’ll destroy the pickup. Instead, send it to a skilled pickup tech, or just spring for a new pickup with the desired magnetic polarity.

Note: Changing a pickup’s magnetic polarity and winding direction will result in the original phase configuration with the same problems you had before.

It’s a wrap. Things can seem complicated and confusing when you look at all the possibilities for magnetic polarity and winding direction. But a compass, DIY phase-testing unit, and the above traffic light table should help you sail through this.

Next time, we’ll dive into another mod. Until then ... may the phase be with you.