CNZ Audio Flanger

The CNZ Audio Flanger is a flanger pedal from CNZ, the maker whose SFL-20 flanger also appears in this lane. A flanger is a modulation effect, and what it does to your sound is distinctive: it mixes two identical copies of your signal, delays one of them very slightly, and keeps changing that delay, which produces the effect's signature sweeping, whooshing motion¹. Players most often describe the result as a jet-engine sweep, and that comparison is not an accident, as the effect's history is tied directly to it.

For more on the effect family as a whole, see the Flanger Pedals type page, and for CNZ's compact SFL-20, see the CNZ Audio SFL-20.

What a flanger does to your sound

Strymon defines the effect plainly: "the flanging effect is created by mixing two identical audio signals, applying a slight delay to one signal, and slightly varying that delay over time"¹. Because the delay is continuously varied, the two signals drift in and out of phase with each other, and the result is a moving series of peaks and notches in your tone, the sweep players hear as whooshing or jet-like.

How that sweep behaves depends on the delay range the pedal uses. Drolo's manual describes the span of sounds available across a flanger's delay control: "pretty wide range, from ear-piercing accelerated jet plane sounds to super boing rubber sounds"². At the shortest delay settings you get the conventional airplane-like flanging; as the delay is increased, very short repeats start to become audible². Jim Dunlop describes the flanger voice of its MXR Flanger/Doubler as "sweeping jet-engine motion and metallic resonance, adding movement and drama to your tone"³.

How a flanger works

The circuit idea is simple to state. EarthQuaker Devices explains it as two identical signals mixed together, with one playing at a slightly slower speed, creating a swooshing effect similar to the sound of a jet engine⁵. In pedal terms, the varying delay is driven by an LFO, a low-frequency oscillator that modulates the timing of the delay up and down automatically⁶. Jon Cusack of Cusack Music sums up the recipe: "Flanger uses a much shorter delay with feedback, giving the jet-engine sweep"⁷. That feedback, sometimes labeled regeneration, feeds part of the delayed signal back through the delay, which intensifies the sweep and sharpens the resonant peaks.

The steps, in order:

1. Your signal is split into two identical copies.
2. One copy is delayed by a very short, continuously varying amount, driven by an LFO⁶.
3. Feedback recirculates part of the delayed copy, deepening the sweep⁷.
4. The two copies are mixed back together, and the moving phase interaction between them becomes the flanging you hear¹.

Flanger versus chorus and phaser

The flanger sits inside a family of time-based modulation effects, and the differences come down to delay length and how frequencies are altered. Pedal of the Day's history article puts it this way: "Depending on how much we delay these signals or alter their frequencies can lead to other effects like chorus, phase, and echoes"⁸. The dividing line between flanger and chorus is delay time: "a flanger uses shorter delay times than a chorus"¹.

Where the flanger came from

The effect predates the pedal. Kemper notes that "flangers originated in the studio by manipulating tape machines, producing their iconic jet-like sweep"⁹. Pedal of the Day's history article traces the lineage to early experiments with audio signals on magnetic tape, including two reel-to-reel machines and pressing on the reels to change their speed⁸. The name itself comes from that practice: engineers literally pressed a finger on the reel's flange to slow one machine against the other.

The effect found its way onto records early. Rush used flanging on "The Spirit of Radio", where, as the article notes, "it helps that opening arpeggio feel like its building even though it is the same notes"⁸. Today the effect is widely available in pedal form, with Strymon, TC Electronic, Electro-Harmonix, Universal Audio and many more all making their own versions of modulation pedals with flanging⁸.

What reviewers say about flangers

Published reviewers tend to judge flangers on their tonal character and range. Premier Guitar's review of the Chase Bliss Audio Spectre Analog TZ Flanger found "the effect quality is lovely, thick, immersive, and three-dimensional"¹⁰. Of the Hartman Analog Flanger, the same magazine's reviewer wrote: "It doesn't sound like an MXR, but it's not intended to. This is an extremely pleasing, and very musical sounding flanger"¹¹. Some makers push the effect further still: the Rainger FX Flanger X adds a built-in analog rocket launch sound with its own volume knob, mixable with the flanger¹².