What is a Phaser Pedal?

A Phaser Pedal is a type of guitar effects pedal that is used to modify the sound of an electric guitar. It belongs to the modulation category of effects pedals and is commonly used in various styles of music, including rock, funk, and psychedelic.

One of the main advantages of a phaser pedal is its ability to add coloration and character to the sound of the guitar. By introducing the swirling effect, the pedal imparts a sense of movement, depth, and dimension to the tone.

Example Phaser Pedal- the Boss PH-1

It can breathe life into a stagnant sound, making it more dynamic and captivating. Whether you’re playing a clean passage or a distorted riff, the phaser can inject an expressive quality that engages the listener.

Brief History of Phaser Pedals

The life of the phaser started in 1967 with the Uni-vibe, a phase-shifting box that is actually labelled a chorus (along with vibrato). It didn’t actually have a footswitch built into it but you could add a foot controller.

The first unit to be labelled a phase shifter was the Maestro PS-1 that was released in 1971. However, it still didn’t contain a footswitch. For that we had to wait until 1974 when the MXR Phase 90 was released for something that resembled the stompboxes we have today. In fact, it’s still available now.

The phaser pedal, a beloved tool for guitarists, experienced its heyday and achieved remarkable popularity throughout the vibrant music scene of the 1970s and 80s. Emerging as one of the quintessential guitar pedals, it captivated musicians with its unique sonic capabilities and distinct sound modulation.

How Does a Phaser Pedal Work? Understanding the Basics.

Essentially, the functioning of a guitar phaser pedal revolves around the manipulation of the guitar’s input signal through a sequence of steps.

First, the pedal splits the input signal into two separate paths. One path preserves the original “dry signal,” while the other undergoes phase shifting. This phase shifting involves altering the phase relationship of the two signals, which entails adjusting the timing of its peaks and troughs.

To achieve this phase shifting, the phaser pedal utilizes a series of all-pass filters. These filters are designed to affect specific frequency ranges within the signal, selectively modifying their phase characteristics.

As the phase-shifted signal passes through these filters, it encounters peaks and notches in its frequency spectrum. These peaks and notches create variations in the amplitude of certain frequencies, resulting in the distinctive swirling and sweeping effect that defines the phaser’s captivating sonic character.

Once the phase shifting process is complete, the pedal combines the altered signal with the original dry signal. This merging of the two paths results in the output signal, which is a combination of the untouched dry signal and the transformed, phase-shifted signal. 

The resulting output signal exhibits the dynamic phaser effect, where the peaks and notches move through the frequency spectrum, creating a unique and engaging audio effect.


While specific controls and features may vary, most phaser pedal models offer knobs to adjust the speed, depth, and feedback of the effect. These parameters allow guitarists to sculpt the phaser’s sound to their liking, whether they prefer subtle, ethereal textures or bold, sweeping sonic landscapes.

Speed Knob/Control

The speed knob, sometimes referred to as the speed control, is one of the primary controls on a phaser pedal. It adjusts the rate at which the phasing effect cycles through the audio signal.

By adjusting it, you can make the phaser’s speed faster or slower, altering the tempo of the effect. Higher settings result in a quicker and more pronounced phase shift, while lower settings create a slower and more subtle phasing effect. This control is essential for matching the phaser’s speed with the rhythm and feel of the music being played.

Depth Control

The depth control on a phaser pedal regulates the intensity or depth of the phase effect applied to the audio signal. It determines how pronounced the peaks and troughs of the phased sound are.

Increasing the depth control produces a more dramatic and noticeable effect, while decreasing it yields a more subtle and understated phasing. By adjusting the depth, guitarists can tailor the phaser effect to suit different musical styles and playing situations.

Feedback Control

The feedback control, found on some phaser pedals, allows users to control the amount of phased signal that is fed back into the effect. When the feedback control is increased, it creates a more resonant and resonating phasing effect.

On the other hand, reducing the feedback control results in a cleaner, less intense phase sound. The feedback control can be used to create psychedelic, swirling textures or dial back the effect for a more conservative phaser sound.

Manual Knob

Sometimes known as a manual control, this control alters the position of the phaser’s notches or peaks manually. By turning it, guitarists can fix the phaser at a particular phase shift position, creating a stationary or “cocked” wah-like effect. The manual control can be a handy tool for adding emphasis to specific frequencies or achieving unique tonal textures.

In summary, most phaser pedals feature controls such as the speed knob, depth control, feedback control (on some models), manual knob, and a mix control to adjust the balance between the dry and phased signals.

These controls allow guitarists to shape the phasing effect, controlling the speed, intensity, resonance, and overall character of the phaser sound. Whether you’re seeking subtle modulation or bold swirling tones, understanding and utilizing these controls will help you unlock the full potential of your phaser pedal.

Where Does Phaser Go in the Signal Chain?

As a modulation effect (which includes chorus and flanger pedals), a phaser pedal is usually located towards the back end of the pedal chain. The only effects that come after are reverb and delay.

Some guitarists prefer to place the phaser before the distortion / overdrive pedals to alter the tone going into the gain stage. Placing it early in the signal chain like this gives a more pronounced sweeping effect.

The Different Types of Phaser Pedals: Analog vs. Digital

When it comes to phaser pedals, there are two primary categories: analog and digital. Both analog and digital phasers have their unique characteristics, creating distinct soundscapes and captivating guitarists in their own right. In this article, we delve into the analog vs. digital phaser debate to help you understand their differences and determine which one suits your musical aspirations.

Analog Phaser Pedals: Embracing Warmth and Organic Tones

Analog phaser pedals rely on analog circuitry to shape the incoming guitar signal. These pedals aim to replicate the classic phaser effect, which was first popularized in the 1970s. Known for their warm and organic sound, analog phasers add a subtle modulation to your guitar tone, creating lush, swirling sonic textures. They excel at producing smooth and musical sweeps that seamlessly blend with your playing.

One of the key aspects that sets analog phasers apart is their alluring “vintage” character. Their circuitry imparts a certain coloration and imperfections to the sound, which many guitarists find highly desirable.

Analog phasers often exhibit a slightly lo-fi quality, delivering a more natural and raw tonal response. The simplicity of their design allows for a more immediate and hands-on experience, with straightforward controls typically comprising rate, depth, and feedback knobs. These controls enable you to dial in a wide range of sounds, from subtle warbles to deep swirling vortexes.

Digital Phaser Pedals: Embracing Precision and Versatility

On the other side of the phaser spectrum, digital phaser pedals offer a more modern take on this effect. Instead of analog circuitry, they employ digital signal processing techniques to generate their sonic manipulations. Digital phasers are designed to provide precise control and offer a vast array of tonal possibilities. They often feature multiple phasing algorithms and adjustable parameters, allowing you to explore an expansive sonic palette.

Digital phasers excel in creating highly intricate and complex modulation effects. With their advanced processing capabilities, they can produce a wide range of phasing effects, from subtle and transparent sweeps to wild and futuristic soundscapes.

The precision and flexibility of digital phasers make them well-suited for experimental genres and players seeking to push the boundaries of traditional phaser sounds. Additionally, digital pedals often include preset functionality and MIDI compatibility, allowing for convenient recall of different settings and integration into larger setups.

The Analog-Digital Dilemma: A Matter of Taste and Purpose

Choosing between analog and digital phaser pedals ultimately comes down to personal preference and the musical context in which you intend to use them. If you prioritize warmth, vintage charm, and simplicity, an analog phaser may be the ideal choice for you. Its organic sound and straightforward controls can provide a classic and soulful modulation experience that appeals to traditionalists and enthusiasts of vintage gear.

However, if you seek versatility, precision, and a broader range of sonic exploration, a digital phaser could be the perfect match.

Digital pedals offer an abundance of tonal options, allowing you to sculpt your phaser sound with meticulous detail. Their ability to replicate classic phaser sounds and create entirely new ones can inspire creativity and open doors to uncharted sonic territories.

In the end, the analog vs. digital phaser pedal debate is not about determining which type is superior, but rather about finding the right tool for your musical needs and artistic vision. Both analog and digital phasers possess their unique sonic characteristics and offer a gateway to captivating and expressive sounds.

Famous Phaser Pedal Users

There are several famous guitar players known for using a phaser pedal to enhance their sound. Here are a few notable examples:

Eddie Van Halen: The late Eddie Van Halen, renowned for his innovative guitar playing with the band Van Halen, often used a phaser pedal to create his signature tone. His use of the MXR Phase 90 is particularly well-known. In fact there is even a signature model out, the EVH90.

David Gilmour: The legendary guitarist of Pink Floyd, David Gilmour, incorporated a phaser pedal into many of his iconic guitar solos. He used the Electro-Harmonix Small Stone Phaser and the MXR Phase 90 to achieve his lush, atmospheric sound.

Jimi Hendrix: Widely regarded as one of the greatest guitarists of all time, Jimi Hendrix frequently used a Uni-Vibe pedal (mentioned above). The swirling phaser sound of the Uni-Vibe played a pivotal role in shaping his psychedelic guitar tones.

Eddie Hazel: Best known for his work with Parliament-Funkadelic, utilized a phaser pedal to achieve his funky, psychedelic phase tone. His use of the Phase 90 is particularly notable.

These are just a few examples of famous guitar players who have incorporated phaser pedals into their playing. There are many more guitarists across different genres who have utilized this effect to add depth and texture to their sound.

You’ll notice too that one in particular is proving itself to be an iconic phaser pedal.

Famous Songs that Feature a Phaser Pedal

Let’s explore a selection of notable songs that have harnessed the power of the phaser, showcasing the versatility and impact of these transformative guitar effects.

  • Shine On You Crazy Diamond – Pink Floyd
  • Have A Cigar – Pink Floyd
  • Eruption – Van Halen
  • Who’s That Lady – Isley Bros
  • Mayonnaise by Smashing Pumpkins
  • Paranoid Android – Radiohead
  • Comin’ Round the Mountain – Funkadelic
  • Shattered – Rolling Stones
  • Anarchy In The UK – Sex Pistols

And let’s not forget…

  • The Dukes of Hazzard Theme by Waylon Jennings

Examples of Top Phaser Pedals: Unleashing Sonic Whirlwinds

When it comes to creating captivating sonic landscapes and adding an ethereal touch to your guitar tones, few effects can rival the mesmerizing power of phaser pedals. These versatile stompboxes have been a staple on countless pedalboards, propelling players into new realms of tonal exploration.

While there are numerous exceptional phaser pedals available, let’s take a closer look at some of the most popular phasers that have been embraced by both renowned guitarists and tone aficionados.

MXR Phase 90: The Classic Whirling Workhorse

If there were ever a phaser pedal that embodied the essence of this effect, it would undoubtedly be the MXR Phase 90. Since its introduction in the ’70s, the Phase 90 has remained a go-to choice for countless guitarists across genres. Its simple one-knob design belies the vast range of lush swirling textures it can produce.

Whether you crave subtle and silky phase sweeps or want to dial in deep, swirling vortexes of sound, the MXR Phase 90 never fails to deliver its signature liquid-like modulation.

Boss PH-3 Phase Shifter: A Shifting Paradigm

Continuing the legacy of Boss’s renowned compact pedal series, the PH-3 Phase Shifter is a dynamic powerhouse that opens up new dimensions of sonic expression. With a plethora of controls at your fingertips, this pedal offers both classic and modern phaser effects.

From vintage four-stage phasing to cutting-edge Rise and Fall modes, the PH-3 enables you to create everything from gentle ripples to dynamic sonic waves. Its ability to sync with other Boss pedals through the innovative Tap Tempo function further expands its creative potential, making it a versatile tool for any sonic adventurer.

Strymon ZelZah Dual Phaser: The Dual Phasing Extravaganza

For those seeking a phaser pedal that pushes the boundaries of sonic manipulation, the Strymon ZelZah Dual Phaser stands tall as a true titan of tonal versatility. Boasting two independent phaser circuits, the ZelZah offers an extraordinary range of sonic exploration.

From classic vintage phasing to cascading waves of swirling textures, this pedal allows you to sculpt and morph your guitar’s sound like never before. With deep editing capabilities and preset storage, the ZelZah invites you to dive into its sonic universe and discover new dimensions of phasing artistry.

These remarkable phaser pedals represent just a fraction of the vast array of options available to guitarists seeking to infuse their playing with captivating swirls of sound.

Whether you’re a seasoned tone seeker or a curious sonic explorer, these pedals are sure to inspire and elevate your musical journey, unraveling sonic whirlwinds and expanding the boundaries of your creativity.


A phaser pedal is a fun and powerful tool that guitarists use to modify and enhance their electric guitar’s sound. With its swirling effect, the phaser pedal adds movement, depth, and dimension to the tone, breathing life into the music and captivating listeners.

Throughout its history, the phaser pedal has evolved, from the Uni-vibe to the Maestro PS-1 and the iconic MXR Phase 90, becoming a quintessential effects pedal in the vibrant music scene of the 1970s and 80s.

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Jason Barnham

Hi. I’m Jay, founder, author, and chief editor at The Vintage Guitarist. I've been playing guitar for nearly 40 years and I absolutely love owning and trying different guitars and related gear.