Guitar 101: What Are Flangers and Phasers? Learn About the Best Flanger and Phaser Pedals for Electric Guitar Players

A flanger works by mixing two identical audio signals together, with one of the signals playing at a slightly slower speed. This creates the effect of two tape recordings playing simultaneously, but with one tape player going slightly slower than the other. Because one of the playback speeds is slower, the distance between the two “recordings” will continue to increase, which can create a swooshing effect similar to a spinning fan blade or even a jet engine.

• The first flange effects committed to tape were by the guitarist and engineer Les Paul. Although known to the masses for his namesake guitar produced by Gibson and Epiphone, Paul was equally regarded for his advancements in recording technology. Throughout the 1930s, 40s, and 50s, Paul experimented with variable speed record players to create two sounds slightly out of phase with one another.
• The actual term “flanging” is often attributed to John Lennon of The Beatles. Lennon, who considered himself an inferior singer to bandmate Paul McCartney, often requested that producer George Martin double-track his vocals to hide certain imperfections. To save time in the studio, Martin and Abbey Road Studios engineer Ken Townsend began employing a technique known as artificial double tracking, or ADT. This allowed the team to play back two versions of a single vocal recording, ever so slightly out of phase with one another. If one of the playback machines played slightly slower than the other, this increased the effect, which Lennon began to call “flanging.”
• The first Beatles recording with vocal flanging was “Tomorrow Never Knows,” and bands have been replicating its sonic characteristics ever since. Lennon himself swore by “flanged” vocals from that point forward. Flanging has also been subtly used on drum performances over the years. But it tends to be most pronounced when applied to a distorted guitar.

Today’s guitar players typically get a flanger effect through a stompbox pedal. Depending on how you dial in the effect, it can be very subtle (like a double-tracked vocal) or highly pervasive, like the nonstop swoosh of a jet engine.

• Boss BF-3. As is often the case with stompbox effects, Boss is considered an industry benchmark. This familiar purple pedal contains controls for resolution, manual, depth, and rate, and the pedal offers several flanging modes through which you can run these parameters.
• MXR EVH117. Eddie Van Halen is known for both his flange and phase effects, and this MXR pedal is designed to replicate his tones. Somewhat wider than the Boss, the EVH117 contains controls for manual, width, speed, and regeneration. It also has a special button to summon “EVH” mode.
• TC Electronic Vortex. Painted purple in homage to the Boss classic, the TC Electronic Vortex stands out for its TonePrint technology. This allows you to important custom settings to the pedal that are designed by top guitarists working in tandem with the manufacturer.
• Joyo JF-07. If you’re on a budget, the Chinese company Joyo can produce impressive recreations of old stompbox classics, and their take on a flanger gives you all the key sounds at a low price point.

Flangers fit into a broader category of effects, known as phasing. Any phase effect involves dual playback of a musical performance. Flangers specifically generate their effect by one playback channel going slower than the other. A phaser pedal, by contrast, does not alter playback speeds. Rather, it puts one playback channel through an all-pass filter that changes the length of each audio phase.

• Most phaser effects contain a series of all-pass filters, which are known as “stages.” A 4-stage phaser and an 8-stage phaser are common among stompbox pedals, but you can’t always predict a pedal’s sound base on how many stages it has.
• Compared to flangers, phasers tend to have fewer controls. In fact the iconic phaser pedal, the MXR Phase 90, only has one control—speed. That dial affects how much the all-pass filters will alter the length of each phase.
• A popular guitar phase setting is to place the speed control at roughly 25%. This creates a subtle effect that recalls a lot of ‘70s and ‘80s hard rock but doesn’t overwhelm your tone like a jet-sweep flanger might. Jimmy Page used this setting on “The Rover” from Led Zeppelin’s Physical Graffiti. It can also be heard in ‘80s hits like The Outfield’s “Your Love.” Meanwhile, Page turned up the speed setting on his phaser for tunes like “No Quarter.” Doing so made the effect far less subtle.
• Like flangers, phasers are also popular atop instruments beyond guitars. Keyboardists frequently use phase effects. Billy Joel uses on on “Just The Way You Are.” In the band Genesis, both guitarist Steve Hackett and keyboardist Tony Banks used phasers on their respective instruments. Meanwhile, the vocoder effect uses a phase-style series of filters to alter and encrypt vocal performances.

Most phaser pedals for electric guitar perform similar functions, but there are still options to consider:

• MXR Phase 90. If there is one pedal synonymous with phasing, it’s the Phase 90. Chances are that if you’ve heard a guitarist playing a phase tone, he or she was using this iconic one-knob orange pedal. MXR has created many variations on this device, including a Phase 45, a Phase 95, a Phase 100, and an Eddie Van Halen signature model. Most players will be fine sticking with the original. Keeping the speed at 25% produces a noticeable yet subtle phase tone.
• Walrus Audio Vanguard Dual Phaser. On the opposite end of the spectrum from the Phase 90 is the Vanguard. Instead of one parameter knob, it has eight. It also has a toggle switch to select between 4-stage, 6-stage, and 10-stage phasing. It offers a pitch effect for vibrato-style modulation and a “regen” knob for flanger-style tones. It’s large and somewhat pricey, but it contains many more tonal options than a small one-knob stompbox.
• EarthQuaker Devices Grand Orbiter. Falling somewhere in between the Phase 90 and the Vanguard is the Grand Orbiter. Like the Vanguard, it features multi-stage phase options and a vibrato-style modulation mode. But like the Phase 90, it has a compact footprint. Price-wise, it’s closer to the Walrus Audio Vanguard, which is appropriate for all the features it offers.

Find more guitar pedals and effects in Tom Morello’s MasterClass.