In our endless pursuit of great tone, it seems that we as guitar players will be willing to do just about anything to get what we’re aiming for. Despite the abundance of pedals and all the different gear these days, we can’t help but think that things used to be more interesting and exciting back in the old days. There were no exact ways of achieving certain effects. In fact, many players weren’t even aware of some effects as the information flow wasn’t as fast as it is today. It must have felt kind of mysterious or “magical” to be left on your own to try and figure out the ways to create these unusual tones.

However, those resourceful few who felt extra experimental managed to pull out some really exciting new tricks. These “tricks” eventually became popular effects that we use to this day. Since it’s still one of the most popular effects among guitar players, we figured we could take a closer look at flanging, find out more about its origins, and see how it actually works.

What is flanger and how it came to be?

Before we get into all the technical details, let us first explore the history of this effect. As the mid-20th century was the time of massive and rapid technological innovations, different people ended up making the same innovations in roughly the same period without ever knowing about one another.

We have somewhat of a similar scenario with the flanger effect, or the so-called “flanging.” The effect traces its roots to the late 1940s or the early 1950s when one of the biggest guitar innovators, Mr. Les Paul himself, began experimenting and came up with the concept where the tone is phasing in and out. Inspired by this innovation, he recorded a piece called “Mammy’s Boogie.” Although more “shallow” as compared to today’s flanging possibilities, you can clearly hear this soft “whooshing” all throughout the piece.

As far as it is known, and as it is widely accepted, Les Paul was the first one who actually used it. However, the name “flanging” or “flanger” come from some of the methods that were developed later on, sometimes in the late 1950s. In fact, the story goes that the term itself was coined by John Lennon of The Beatles in the 1960s when he was exposed to this peculiar effect by engineer Ken Townshend. But we’ll get to that later.

While Les Paul’s method involved record players and acetate discs, a great breakthrough in flanging was done by the founders of the legendary Gold Star Studios, Stan Ross and David Gold, in the late 1950s by manipulating the tape machine. However, it wasn’t until the mid and late 1970s when Eventide, MXR, and other manufacturers released their effects units (mostly rack-mounted) which did this same effect using solid-state technology. It was all thanks to the so-called “bucket brigade devices,” or BBD, that we got analog flanger, chorus, phaser, and delay pedals.  We dove more into this topic in one of our previous articles.

These days, most of these modulation effects are all done through digital processing. Even the unique and “warm” tone of analog effects can be replicated through some refined multi-effects processors or amp modelers, like Kemper and Axe-FX.

How it works

Not to get too technical, we’ll try to explain how all this works. We could say that these early examples of flanging were “mechanical” in nature as it included physical tampering with reel-to-reel magnetic tape recorders. The flanging is based on playing two copies of one recording at the same time and manipulating their playback speed. One is unaltered, played at the original speed, while the other is just slightly manipulated to cause a very brief time delay. This causes the so-called “phase cancellation.”

For those who don’t know, “phase” is where exactly the waveform of the signal is in its current cycle. Phase cancellation occurs as the relationship between the two same exact copies of the signal where one is delayed. This creates that recognizable illusion, that “swoosh” or “jet engine” effect. By further manipulating this slight delay on one recording, the canceled frequencies change and you get the different frequencies going through in the output.

During the 1960s, this was done by starting two reel-to-reel tape machines at the same exact time and then sending their output to the third tape recorder. The engineer then literally presses one of the tape flanges to achieve that brief delay. The third machine records both of these tapes and mixes them together on one tape.

The aforementioned engineer Ken Townshend did this same exact thing for the recording of one of The Beatles’ songs at the Abbey Road Studio during the recording of the “Revolver” album. After everyone was tired from double recording all the vocals, Townshend showed this trick that managed to emulate two overdubbed vocal takes. After seeing what Townshend is doing, John Lennon reportedly gave the name to the effect – “flanging.” The first song The Beatles used it on was “Tomorrow Never Knows.”

It’s interesting to see when an effect desired by musicians is considered to be an “error” by engineers. This was also the case with distortion, with musicians even deliberately damaging their amps to achieve this effect. As for flanging, Jethro Tull stumbled upon unwanted flanging issues during the recording of “Thick as a Brick.” This was the case with very long musical pieces recorded on one track. To put it simply, the literal weight of the track would slow down one of the tracks during the overdubbing process, making it go “out of phase.”

Comb filter

The flanging itself causes the so-called “comb filter” effect. Every audio signal can be presented as more or less of a sine curve with all of its notches and peaks in the frequency spectrum. When you have one of the recordings delayed, there’s a lot of cancellation of the same frequencies going on. The graphic representation of uncancelled frequencies ends up looking as teeth on a comb, thus the name “comb filtering.”

How is it different from chorus and phaser effects?

Chorus, phaser, and flanger all fall into the category of so-called “modulation” effects. In fact, flanging is a type of phaser effect. Below, we’ll try to give a brief explanation of how they are all different from one another.

First off, we have chorus. Aside from slightly delaying the copied signal, it is also altered through low-frequency oscillation which results in slight changes in the pitch. Mixed together, you get the impression as if there are two instruments playing the same thing at the same time. Of course, this change in pitch can be pushed to some “unconventional” levels to create that swirly and crazy effect.

Then we have flangers. One again, we have two same exact signals where one of them is delayed on purpose. And because they’re exactly the same, there will be some “interference” in the frequencies, and you’ll get the aforementioned “comb filter” effect. Of course, the interference will happen at some of the harmonically related intervals, this means that the flanger effect depends on the harmonic relationships between the two signals themselves. One important thing to point out about flangers is that the delay times are really short, meaning that higher frequencies will be pronounced. And by modulating the delay time, the points where frequencies interfere will change and you’ll get the impression of “movement.”

One more thing that modern flangers do is that they use feedback as well by sending the output signal back into the input in order to get more processing of the original signal.

And then we have the phaser effect. What’s interesting is that the phaser does not use any kind of time delay on the copied signal. Instead, it is just taken out of phase through the so-called “all-phase filter.” You don’t get any alteration of the frequency content.

Parameters to control

An average flanger effect unit, like your standard flanger pedal, will have a few parameters to control which will create different types of that “jet engine whoosh” effect. The first two basic effects on all flanger pedals are “rate” and “depth.” By tweaking the “rate” control, you get the different speed of the effect, anything from a slow rise and fall up to fast swirls. “Rate” can sometimes be labeled as “speed.”

The next control that you’ll find is “delay.” This one determines the delay of the copied signal. Delay times on a flanger usually anywhere between 1 and 20 milliseconds.

A lot of the flanger pedals will also have “resonance” or “feedback” controls. These will further enhance the effect by feeding back the processed signal back into the input. As a result, you get numerous decaying repeats, sort of like a delay fed back into the input many times.

What are some great flanger pedals?

These days, there is an abundance of flanger pedals to choose from. Aside from digital ones, you’ll also be able to find analog flangers that rely on the old BBD chips. While the discussion of digital versus analog deserves an article on its own, we’ll just separate them into these two categories.