Flanger vs. Phaser: What’s the difference?

Flangers and phasers are two very similar types of effects pedals that each change your guitar’s sound in a distinct way. Being modulation effects, they both “modify” the pitch or volume of a guitar signal in different ways.

In this article, I will break down the innate differences between flangers and phasers, give some examples of my favorite pedals, and advise you on how to use these effects. So, let’s dive in, shall we?


  • Simply put, flangers create sweeping sounds by delaying and modulating a repeated signal. 
  • Phasers create a succession of peaks and troughs in the frequency spectrum by dividing the input signal into two or more paths and delaying one of them.

What are modulation effects?

In order to give variety and motion to your guitar’s signal, modulation effects are used to change the signal’s pitch, loudness, phase, or frequency. 

Phasers and flangers, which fall under this category, have a ‘Rate/Speed’ knob for adjusting the frequency at which the corresponding motions occur and a ‘Depth’ knob for adjusting the degree or intensity to which they are exhibited. Other types of modulation effects are tremolo, vibrato, and chorus. Be sure to check out my article on the different modulation effects for more on this.

What is a flanger?

A flanger is an audio effect used frequently in guitar recordings, music production, and live performances. It works by making a copy of your signal, delaying it by 15 to 20 milliseconds, and then recombining it with the original signal. 

This results in a series of comb-filtering effects in which certain frequencies are boosted while others are attenuated, producing a swirling, sweeping sound.

The term “flanger” comes from the early days of audio processing when the effect was achieved by simultaneously playing back two identical audio tapes and slightly delaying one of them by varying amounts using a flange or rim of a spinning reel.

So while the two signals start at the same point, the duplicated voice, which is slower than the original, diverges slowly over time as it oscillates slightly slower. This phase interference between the two signals causes comb filtering. 

As the effect became popular, flanger pedals were designed using digital signal processing (DSP) techniques, which allow for more accurate rhythmic control over the delay parameters.

An LFO (low-frequency oscillator) is generally used to modulate the delay time for a more dramatic sweeping effect., You can easily go from a mild shimmering to ethereal, alien-like flanging effects by modifying the modulation rate and depth.

Flanging is specifically potent on electric guitars, where it can create an almost robot-like metallic sound that is heard widely in hard rock and sub-genres of metal. 

Over the years, flangers have also been used on vocals, acoustic guitars, synths, and drums, as producers started to notice the wide variety of textures and motion-based effects they can generate.

I’ve listed below some of the greatest hits which feature a flanger on the guitar in their recordings:

Unchained (Van Halen)

This is one of the most recognizable examples of a Van Halen song with a flanger, where Eddie Van Halen’s guitar solo featured the distinctive, swirling flanging effect. Van Halen used a flanger extensively in his playing, and MXR has even launched an EVH Flanger pedal. This pedal has a button that will give you the same sound as Van Halen in “Unchained”.

Here are some settings you can use to achieve a similar flanger effect:

  • Rate set to around 400Hz
  • Depth at 10%
  • Delay time at around 750ms
  • A sine wave LFO 
  • Feedback at 80%

Barracuda (Heart) 

The extremely catchy and memorable intro features a flanger on the guitar riff, creating the swirling movement before Ann Wilson delivers her verses.

You might have to use your ears for the feedback settings. Besides that, these settings should work:

  • Rate between 1200-2000Hz
  • Depth at 80%
  • Feedback to taste

Besides these hits, guitarists like The Edge from U2 and Tom Morello have taken flangers to their extremes, not to mention Jimi Hendrix, Eric Johnson, and Frank Zappa, who have all used it in their own unique ways.

What is a phaser?

To generate the phaser effect, an audio signal is first divided into two or more routes, modifying the phase of one or more of the paths and then recombining them. So, while a flanger simply modulates by adding a delay to a cloned track, a phaser shifts the phase of the waveform.

The copies are run through an all-pass filter that alters the peaks and troughs of the copied signal and re-matches it with your original signal, making it go in and out of phase. 

For the most part, the all-pass filter of a phaser pedal is constructed as a cascade of stages. An audio signal is phase-shifted at each stage by a series of components, including capacitors, resistors, and operational amplifiers. A phaser pedal will generally include anywhere from four to twelve steps.

Some frequencies are canceled out or boosted due to the changing phase, resulting in the typical phaser sound. This makes a sweeping, throbbing, pulse-like sound that is commonly described as “phasing.” 

I’ve listed below some of the greatest hits which feature a phaser on the guitar in their recordings:

Good Times Bad Times (Led Zeppelin)

This famous classic rock tune has a phaser effect on its intro guitar riff. Although it’s not very noticeable, the phaser effect gives the guitar in this song a unique, swirling appearance.

Here are some settings you can use to achieve a similar phaser effect:

  • Number of stages: 4-6
  • Depth: 30-50%
  • Rate: Medium-slow
  • Feedback: Less than 25%

Stomp (Brothers Johnson)

The main guitar riff in this funk classic has a more prominent phaser effect than “Good Times Bad Times.” With a faster rate setting and a more pronounced whirling effect, the phaser really sets the mood in this song.

Here are some settings you can use to achieve a similar phaser effect:

  • Number of stages: 8-12
  • Depth: 60-80%
  • Rate: Fast
  • Feedback: Roughly 5-25% 

Main differences between a phaser and a flanger

While both are primarily modulation effects, there are two noticeable differences between a phaser and a flanger:

  • Frequency response: A phaser typically affects the midrange frequencies of a signal, whereas a flanger affects a broader range, including the high and low frequencies.
  • Modulation: Phasers do not use a delay to modulate your sound; instead, they shift the high-end frequencies of your sound around the audio spectrum by shifting the phase of your soundwave. A flanger, on the other hand, employs a time-delayed signal to generate a more dramatic and dynamic modulation effect.

Pros and cons of using flangers


  • Flangers can add movement and excitement to your electric guitars or anything you pass them through by producing a distinct, dynamic sound.
  • They are quite wild and can produce a wide range of effects, from delicate sweeps to loud, swooshing sounds.
  • They are an excellent fit in rock and metal, working well in tandem with overdrive and  distortion-based rhythm tones and high-gain lead tones.


  • Flangers can be overbearing and may only be well-suited in some musical situations. They may be too overpowering in some genres or songs.
  • They can be challenging to use, particularly for beginners. Further experience and experimenting may be required to dial in a flanger setting that works well within your band’s sound/musical context.

Pros and cons of using phasers

  • Besides being able to add subtle depth and movement to your guitar or any other instrument, phasers tend to be easier to control than flangers.
  • Their unique sound allows you to play your instrument differently. This has led to great experimentation in many musical genres, ranging from psychedelic rock to funk and pop.


  • Since they are quite delicate, phasers can get lost in a mix if combined with other modulation pedals. 
  • Certain genres of music or playing styles may not be best suited with phasers. They are frequently associated with psychedelic or spacey sounds when used in their full grandeur. There may be better fits for cleaner tones. However, don’t refrain from trying them out in smaller proportions. 

Lev’s pick: best phaser pedal

MXR Phase 90

The MXR Phase 90 is a phenomenal analog phaser pedal that has been the go-to phaser pedal for countless guitarists over the years. Here are a few reasons why the MXR Phase 90 pedal rocks:

  • Single-knob design: The Phase 90 has a simple yet versatile design with only one control knob, making it simple to operate. However, don’t underestimate the single ‘Speed’ knob, as it can produce a variety of distinct tones.
  • Classic analog phasing: Its phasing effect is created using analog circuitry, producing a warm, organic sound that many guitarists prefer over digital phasers.
  • Robust design: It’s built like a tank and can resist the stresses of touring and performing without malfunctioning or losing sound quality.

Lev’s pick: best flanger pedal

Boss BF-3 Flanger

Unlike its analog predecessor, the BF2 with a BBD bucket-brigade chip, the Boss BF-3 Flanger is a digital flanger pedal with a variety of sounds and functions, including tap tempo, stereo output, and several different modes. 

I’ve listed below a few reasons why the Boss BF-3 Flanger pedal totally rocks:

  • Sonic versatility: The BF-3 can produce a wide spectrum of sounds, from modest sweeps to powerful swooshes, and it can even replicate vintage tape flanging effects.
  • Intricate controls: The pedal includes a variety of knobs and switches for fine-tuning the flanger effect, as well as a manual mode for creating your own unique sweeps.
  • Ultra mode: Increase the values of ‘Depth’ and ‘Resonance’, then set the ‘Rate’ to the tempo of your music, and the ultra setting will provide the flanger effect with greater depth and richness.
  • Gate mode: Adjust the ‘Rate’ control to match the tempo of your music, then set the ‘Depth’ and ‘Resonance’ parameters to a moderate degree. The gating will become more evident as the flanger slowly fades away.

To make more wild and fascinating sounds, pair the BF3 in gate mode with a distortion and a delay pedal.

Want to learn more about how effects pedals work and how to use them? Check out my ultimate guide to effects!