What Is Out-of-Phase Wiring? The “Peter Green” Sound, Explained From the Bench

Here’s the short version: out-of-phase is what you get when two pickups are switched on together but one of them has been electrically reversed, so a big chunk of what they share cancels out. You’re left with a thin, hollow, nasal honk — sometimes described as a “cocked wah” or a quack. It’s the sound Peter Green got out of his ’59 Les Paul, and it’s one of those tones players either chase for years or switch to once and never touch again.

I get asked about this constantly, usually by someone who flipped to the middle position, heard something thin and scooped, and wondered whether their guitar was broken. It almost never is. Here’s what’s actually happening, where the famous version came from, and whether it’s something you want on a guitar you’re buying.

What “out of phase” actually means

Every pickup turns string vibration into an AC voltage — a little wave that swings positive and negative. When two pickups are on together, their waves add up. If both pickups are wired and magnetized the same way (“in phase”), those waves mostly reinforce each other and you get a full, strong signal. That’s a normal middle position: fat, a little scooped, but with plenty of body.

Reverse one pickup — flip its electrical polarity so its wave swings the opposite direction — and now the two signals fight instead of cooperate. Wherever they overlap, they cancel. Because two pickups sitting a few inches apart share most of their low and low-mid content, that’s exactly what gets subtracted. What survives is the thin, reedy top end and a bit of ragged residue. That’s the honk.

One thing worth clearing up: it never fully cancels to nothing. People sometimes picture the two waves perfectly erasing each other, but the pickups sense different points along the string, so their signals aren’t identical. You lose the meat and keep a quacky ghost of the tone. The closer the two pickups sit to each other, the more complete the cancellation and the thinner it gets — which is why an out-of-phase Stratocaster mod sounds far more drastic than two humbuckers on a Les Paul.

Why it only shows up in the middle position

This trips people up, so it’s worth stating plainly: a reversed pickup sounds completely normal on its own. You can’t hear absolute polarity — a wave that starts by pushing instead of pulling is inaudible in isolation. Phase is a relationship between two signals, so it only matters when both pickups are running together.

So on a standard two-pickup guitar, the neck-only and bridge-only positions are unaffected. It’s only the middle (both-on) position that turns weird. If someone tells you their neck pickup “sounds out of phase” by itself, something else is going on — a grounding problem, a dying pickup, or a bad description of a muddy tone.

The Peter Green accident that made it famous

The most celebrated out-of-phase tone in the world happened by mistake. Peter Green’s 1959 Les Paul — the guitar now known simply as “Greeny” — had the magnet in its neck pickup reinstalled backwards at some point, reversing that pickup’s magnetic polarity relative to the bridge. The result was a middle position that sat out of phase: that vocal, hollow, slightly strangled voice you hear all over the early Fleetwood Mac records and, later, Gary Moore’s playing.

Green played it through his years with Fleetwood Mac, then sold it to Gary Moore in the 1970s, who used it for decades. In 2014 it surfaced again when Metallica’s Kirk Hammett bought it, reportedly for somewhere around two million dollars. Gibson and Epiphone have both built “Greeny” reproductions since, and the giveaway spec is always the same: a neck pickup mounted with a reversed magnet so the in-between tone comes out of phase.

What makes Green’s version special isn’t just that it’s out of phase — it’s how he got there. A flipped magnet and a swapped pair of wires both put a pickup out of phase, but they don’t sound identical.

Two ways to get there — and they don’t sound the same

Flip the magnet. This is the Peter Green method — physically turning the pickup’s magnet over so its north/south orientation reverses. Many players and techs describe the magnetic version as the more musical of the two: it seems to depend a little on pitch, so the effect is less brittle and the tone keeps a bit more character. It’s a fiddlier job because you’re opening the pickup, and on a humbucker it changes how that pickup’s hum-cancelling lines up with its partner.

Swap the two wires. The simpler route is electrical: take one pickup’s hot and ground and reverse them, usually through a push-pull pot or a mini switch so you can flick the effect in and out. It’s reversible and easy to live with, but a lot of ears hear the pure electrical flip as slightly harsher and more clinical than the magnet trick.

Whichever route, understand what this isn’t. Out-of-phase is not a coil-split (which drops a humbucker to one coil for a single-coil-ish sound), and it’s not series/parallel switching (which changes how a humbucker’s two coils are connected). Those are separate mods with separate sounds, and they get mixed up constantly.

What it actually sounds like — and whether you’ll like it

Honest take: out of phase is a spice, not a main course. It’s thin, nasal, and a little rude — fantastic for a clean funk chop, a stinging blues lead that needs to cut, or that instantly recognizable Green/Moore vocal quality. It is not the sound you’ll want for big open chords or a fat rhythm tone, because the low end you’d normally lean on is exactly what got cancelled.

It also behaves better on humbuckers than on tightly-spaced single coils. Because a Les Paul’s two humbuckers sit fairly far apart, the cancellation is partial and the tone keeps some weight; run the same trick on two adjacent single coils and it gets so scooped that many players find it unusable for anything but a quick effect. It’s a love-it-or-leave-it tone, and there’s no shame in leaving it — which is exactly why it’s worth hearing in your own hands before you commit to a mod.

Should you care when buying a used guitar?

Two practical angles. First, if you’re shopping for the sound, a factory push-pull or a “Greeny”-style reversed-magnet guitar gives it to you with no soldering. Second — and this is the one I flag on the bench — if a used guitar’s middle position sounds unexpectedly thin and honky and the seller didn’t mention a mod, someone may have wired a pickup backwards by accident during a repair. That’s not damage, and it’s a five-minute fix, but it tells you the electronics have been in and out, so give the rest of the wiring a look.

On a well-sorted guitar, the middle position should sound full unless it’s deliberately wired otherwise. When we go through the two-humbucker guitars in our in-stock collection — things like the Les Paul Standard ’60s or the Les Paul Classic — checking that middle position for phase is part of the once-over. If a guitar you’re looking at is supposed to be stock and the in-between position sounds hollow, ask the seller about it.

FAQ

Is an out-of-phase guitar broken?

No. It’s a wiring or magnet configuration, not a fault. The only time to worry is if the middle position turned thin unexpectedly on a guitar that’s meant to be stock — that usually means a pickup was reconnected backwards, which is easily corrected.

Does out-of-phase wiring damage pickups or hurt tone in the other positions?

Not at all. The neck-only and bridge-only positions are completely normal. Reversing a pickup’s polarity doesn’t harm it — you can flip it right back with no ill effects.

What’s the difference between out-of-phase and a coil-split?

A coil-split turns a humbucker into a single coil for a brighter, thinner solo sound. Out-of-phase leaves both pickups full but reverses one so their combined middle tone hollows out. Different mechanisms, different sounds — and you can have both on the same guitar.

Can I add out-of-phase switching to a guitar I already own?

Usually, yes — a competent tech can add a push-pull pot or mini switch that reverses one pickup’s leads, giving you the effect on demand without changing anything else. It’s reversible, which makes it one of the lower-risk mods out there.

Out-of-phase is one of those tones that sounds like a mistake until it’s the exact thing a song needs. Now you know what it is, where the legend came from, and what to listen for when you’re trying guitars.