MXR Phase 90 Phaser Guitar Effects Pedal, (Used)

The MXR Phase 90 is one of the most recognisable analogue phaser pedals ever produced, delivering the warm, swirling modulation and unmistakable sweeping sound that has helped shape countless guitar tones since the 1970s. With its distinctive orange enclosure, straightforward single-knob control and rich analogue character, the Phase 90 remains a favourite among guitarists seeking everything from subtle movement and vintage warmth to dramatic, fast-moving phase effects.

Built around a classic four-stage phasing circuit, the MXR Phase 90 adds depth, movement and texture to clean and distorted guitar sounds without requiring complicated settings. Its single Speed control makes it exceptionally easy to use, allowing players to move from slow, spacious sweeps to fast, pulsating modulation simply by turning one knob.

The Phase 90 is particularly well suited to classic rock, blues, funk, psychedelic rock and alternative music, while its distinctive character also works well with bass guitars, keyboards and other instruments.

This particular example is presented in Very Good Pre-Owned Condition and is supplied without a power supply. The pedal can operate using a standard 9V battery or a suitable regulated 9V DC centre-negative adapter.

For players looking for a second-hand MXR Phase 90 with classic analogue modulation, intuitive controls and decades of musical heritage, this is an excellent addition to almost any pedalboard.

At A Glance

Pre-Owned Condition Report

Very Good Condition

This MXR Phase 90 is presented in Very Good Pre-Owned Condition, indicating some cosmetic wear consistent with careful previous ownership. The Phase 90's robust metal enclosure is designed for regular pedalboard use, while its simple control layout makes it particularly practical for musicians who prefer reliable, straightforward effects.

Please refer to the product photographs for a closer look at the pedal's individual cosmetic appearance, including any minor marks or signs of use.

Power Supply Not Included

No power supply is included with this pedal. The standard MXR Phase 90 operates from a regulated 9V DC centre-negative adapter or a single 9V battery. Customers using a pedalboard power supply should ensure the selected output provides the correct voltage, polarity and connector.

What's Included

- MXR Phase 90 Phaser Guitar Effects Pedal

Not Included: Power supply.

Fair Deal Music Quality Control Assessment

Fair Deal Music's pre-owned effects pedal assessment covers the important areas of general operation, including input and output connections, footswitch functionality, control response, signal integrity and the operation of the effect circuit. For the MXR Phase 90, particular attention is given to the Speed control and the consistency of the phasing effect at different settings. Individual testing results for this particular pedal have not been separately provided.

Key Features

• Classic Analogue Phaser: Warm, sweeping four-stage phase modulation with a distinctive vintage character.

• Single Speed Control: Easily adjust the rate of the phasing effect without complicated controls.

• Wide Modulation Range: From slow, subtle movement to fast, swirling and pulsing effects.

• True Hardwire Bypass: The standard M101 circuit bypasses the effect when disengaged.

• Robust Metal Enclosure: Durable construction suitable for pedalboard and live use.

• Compact Design: Fits easily into most conventional pedalboard setups.

• Distinctive Orange Finish: The instantly recognisable appearance of the standard MXR Phase 90.

• 9V Battery or DC Operation: Flexible power options for standalone or pedalboard use.

• Low Current Consumption: The standard M101 requires approximately 5mA.

• Very Good Pre-Owned Condition: An appealing alternative to purchasing a new analogue phaser.

Why You'll Love It

The MXR Phase 90 is proof that great guitar effects do not need complicated controls. Its entire sound is shaped using a single Speed knob, making it one of the most intuitive modulation pedals available.

At slower settings, the Phase 90 produces a gentle, moving texture that adds warmth and depth to clean chords, arpeggios and melodic guitar parts. Increasing the Speed introduces more pronounced movement, creating the swirling, animated sounds associated with classic psychedelic rock and vintage analogue modulation.

Its relatively simple design also makes it extremely versatile. The Phase 90 can enhance clean tones, add movement to overdriven rhythm playing or create a distinctive character when combined with distortion, delay and other modulation effects.

For musicians who value expressive analogue sounds, simplicity and a pedal that is easy to incorporate into an existing setup, the MXR Phase 90 remains an outstanding choice.

Detailed Features & Benefits

Classic Four-Stage Analogue Phasing

The MXR Phase 90 uses a traditional four-stage analogue phasing circuit to create its characteristic sweeping modulation effect. Rather than repeating the signal like a delay or creating a doubled sound like a chorus, the circuit shifts the phase of selected frequencies and combines the processed signal with the original, producing moving peaks and notches across the frequency spectrum. This creates the familiar warm, swirling character that makes the Phase 90 especially effective for adding movement and texture without completely changing the underlying guitar tone.

Single Speed Control

One of the Phase 90's defining features is its remarkably simple single-knob design, with the Speed control adjusting the rate of the modulation effect. Turning the knob anticlockwise produces slower, more spacious sweeps that work particularly well with sustained chords and clean passages, while clockwise adjustments introduce faster, more animated movement. This straightforward arrangement allows players to make quick tonal changes during rehearsals or performances without needing to manage multiple parameters, making the pedal equally accessible to beginners and experienced musicians.

Warm, Organic Modulation

The Phase 90 is particularly appreciated for its smooth analogue character, adding a sense of depth and movement that complements the natural sound of an electric guitar. At moderate settings, the effect can introduce subtle colour and animation without overwhelming the original signal, making it useful for rhythm parts and melodic accompaniment. More pronounced settings create the distinctive sweeping sound associated with classic phaser effects, allowing players to transform simple chord progressions, sustained notes and lead passages into more expressive musical textures.

From Subtle Movement to Fast Swirling Effects

The Phase 90's modulation range makes it suitable for a surprising variety of musical applications despite its minimal controls. Slower settings create a gentle sense of motion that can sit comfortably underneath clean guitar parts, while faster settings produce more obvious movement, particularly when applied to sustained chords or distorted lead tones. This allows the same pedal to move between understated atmospheric textures, classic rock modulation and exaggerated psychedelic effects without changing instruments or adding additional processing.

Four-Stage Phaser vs Chorus & Flanger Effects

Although phaser, chorus and flanger pedals are all modulation effects, the Phase 90 produces a distinctive sound through phase shifting rather than the short time-delay techniques used by chorus and flanger circuits. This gives it a smoother, more rounded sweep that often blends naturally with the dry guitar signal, particularly when combined with overdrive or distortion. For players who want movement and depth without the more obvious doubling of chorus or the metallic resonance of a flanger, the Phase 90 offers an appealing alternative.

Responsive with Clean & Distorted Sounds

The MXR Phase 90 works equally well with clean and overdriven guitar tones, making it useful across a broad range of amplifiers and playing styles. On clean settings, it introduces a gentle swirling texture that suits funk, pop, blues and psychedelic music, while combining it with overdrive or distortion creates more pronounced movement and harmonic complexity. The pedal can be positioned before or after gain effects depending on the desired response, giving players further opportunities to experiment with how the modulation interacts with their existing sound.

Simple Footswitch & True Hardwire Bypass

The standard MXR M101 Phase 90 uses a straightforward footswitch to engage or bypass the phasing effect, with a red LED indicating when the pedal is active. Its true hardwire bypass design allows the signal to pass through without the phase circuit being engaged when the effect is switched off. The uncluttered control layout is particularly useful on a busy pedalboard, where quickly engaging the effect or adjusting modulation speed is often more important than having a large selection of presets and secondary controls.

Compact, Roadworthy MXR Construction

The Phase 90's distinctive orange metal enclosure has become one of the most recognisable designs in guitar effects history. Its compact footprint makes it easy to accommodate on conventional pedalboards, while the sturdy construction is intended to withstand the demands of rehearsals and live performance. The simple control arrangement also reduces the likelihood of accidentally changing several settings when operating the pedal, making it a practical choice for musicians who prefer dependable, hands-on effects.

Versatility Beyond Electric Guitar

Although best known as a guitar effects pedal, the MXR Phase 90 can also be used with bass guitars, keyboards and other suitable instruments. Its sweeping modulation can add movement to sustained keyboard sounds, introduce animation to bass lines or create unusual textures when used as part of a recording setup. This makes it a useful creative tool for musicians and producers who want to experiment with analogue modulation across different sources rather than limiting the pedal to one instrument.

Who Is It For?

Beginner Guitarists: The single Speed control makes the Phase 90 an excellent introduction to modulation effects, allowing players to explore phasing without complicated settings.

Intermediate Guitarists: A great option for musicians looking to expand their pedalboard with classic analogue modulation.

Classic Rock Players: The Phase 90 is particularly suited to the warm, sweeping phase sounds associated with 1970s and 1980s rock guitar.

Blues Guitarists: Slower settings can add subtle movement and depth to expressive lead playing without overpowering the natural guitar tone.

Funk & Soul Players: Its rhythmic modulation works well with clean chord stabs, percussive rhythm playing and repetitive guitar patterns.

Psychedelic & Alternative Musicians: Faster settings and combinations with distortion, fuzz and delay offer a wide range of creative textures.

Recording Musicians: The simple controls and distinctive analogue character make the Phase 90 useful for quickly introducing movement into recorded guitar and keyboard parts.

Playing Styles & Applications

The MXR Phase 90 is particularly well suited to classic rock, psychedelic rock, blues, funk, soul, indie, alternative rock, progressive rock and ambient music.

Its slow sweeping effect is excellent for adding subtle movement to clean chords and arpeggios, while faster settings create an animated sound that works especially well with sustained notes and distorted guitar.

When used before overdrive or distortion, the modulation interacts with the gain stage to create a more integrated and often pronounced tonal movement. Placing the Phase 90 after distortion generally produces a clearer, more prominent sweeping effect.

For recording, the pedal is useful for adding texture to guitar overdubs, bass lines, keyboard parts and atmospheric arrangements.

How It Compares

MXR Phase 90 vs MXR Phase 95

The MXR Phase 95 is a more compact and flexible alternative that combines Phase 90 and Phase 45-style circuits with additional voicing options. While the Phase 95 provides greater variety, the standard Phase 90 focuses on one familiar four-stage phasing sound with a single control. Guitarists who value simplicity and the traditional Phase 90 experience may prefer the original-style design, while those seeking additional modulation options from a smaller pedal may favour the Phase 95.

MXR Phase 90 vs MXR Phase 100

The MXR Phase 100 offers a broader selection of phasing characteristics through additional controls, allowing players to explore different modulation intensities and sweep patterns. The Phase 90 provides a more straightforward approach, concentrating on its recognisable four-stage sound with the Speed knob as the only adjustment. Players who prefer simple operation may find the Phase 90 more convenient, while musicians seeking greater control over modulation character may appreciate the Phase 100.

MXR Phase 90 vs Electro-Harmonix Small Stone

Both the MXR Phase 90 and Electro-Harmonix Small Stone are established analogue phaser pedals, but they offer different tonal personalities and control arrangements. The Phase 90 is known for its smooth four-stage sweep and simple Speed control, while the Small Stone adds a Colour switch for altering the character of its modulation. The choice largely depends on the player's preference for each pedal's distinctive phasing sound and whether additional voicing options are required.

MXR Phase 90 Heritage

The MXR Phase 90 was introduced in 1974 and became one of the defining effects pedals of the emerging compact stompbox era.

Its distinctive orange enclosure and simple control layout made it instantly recognisable, while its warm analogue phasing became an important part of guitar sounds throughout the 1970s and beyond.

The Phase 90 is closely associated with Eddie Van Halen, who famously incorporated the effect into his guitar rig, helping establish its reputation as a classic rock modulation pedal.

Over the decades, MXR has produced several versions of the Phase 90, including the standard Block Logo model, Script variants and signature editions.

Despite these variations, the basic concept remains remarkably consistent: a compact analogue phaser capable of delivering a broad range of expressive modulation through a single Speed control.

For players interested in classic guitar effects, the Phase 90 represents an important part of pedal history and remains one of the most approachable ways to explore analogue phasing.

Technical Specifications

The table below reflects the standard MXR M101 Phase 90 specification. The precise edition of this pre-owned pedal has not been supplied, so variant-specific details should be checked against the individual unit.

Power Requirements

The standard MXR Phase 90 operates using a regulated 9V DC centre-negative power supply or a single 9V battery.

The standard M101 model has a current draw of approximately 5mA, making it suitable for most conventional pedalboard power supplies with a compatible 9V output.

A Dunlop ECB003-compatible adapter or a suitable isolated 9V DC pedalboard power supply can be used, provided the voltage, polarity and connector are correct.

The pedal can also operate using a standard 9V battery, accessed by removing the bottom plate.

No power supply is included with this pre-owned pedal.

Fair Deal Music Expert Verdict

★★★★★

The MXR Phase 90 remains one of the most enjoyable and accessible analogue modulation pedals available, combining an instantly recognisable sound with remarkably simple operation.

Its classic four-stage phasing circuit delivers everything from subtle, warm movement to pronounced swirling effects, making it equally useful for blues, classic rock, funk, psychedelic music and modern alternative styles.

The single Speed control is a major part of its appeal, allowing musicians to make immediate tonal adjustments without navigating complicated settings or menus.

For guitarists building their first pedalboard or experienced players seeking an unmistakable analogue modulation sound, the Phase 90 offers a distinctive character that continues to stand the test of time.

This particular example is presented in Very Good Pre-Owned Condition and offers an appealing opportunity to add a classic MXR effect to an existing setup.

Best Suited For: Guitarists seeking classic analogue phasing for rock, blues, funk, psychedelic and alternative music.

Customers Usually Upgrade From: Basic multi-effects processors, entry-level modulation pedals or simple digital phaser effects.

Most Commonly Paired With: Overdrive pedals, distortion pedals, fuzz pedals, delay effects and clean or lightly driven guitar amplifiers.

Our Tip: Start with the Speed control around 9 o'clock for a slow, smooth phase sweep. Increase it towards noon for a more pronounced classic rock effect, or turn it further clockwise for fast, animated modulation.

Showroom Advice: Experiment with the Phase 90 both before and after your overdrive pedals. The position can significantly affect how prominently the phasing movement comes through in your final guitar sound.

Why Buy Pre-Owned From Fair Deal Music?

Buying a pre-owned MXR Phase 90 from Fair Deal Music provides an opportunity to enjoy one of the most established analogue modulation effects at an attractive alternative to purchasing new.

Our experienced team understands the importance of clear condition grading, accurate product descriptions and practical guidance when choosing effects pedals.

This particular MXR Phase 90 is presented in Very Good Pre-Owned Condition, with the absence of a power supply clearly identified.

For musicians expanding their pedalboards, buying pre-owned equipment can provide excellent value while extending the useful life of quality musical gear.

Why Buy From Fair Deal Music?

When you buy from Fair Deal Music, you're choosing one of the UK's most established, independent family run music retailers since 1987.

As Birmingham's largest independent music store, we have spent nearly four decades helping musicians find the right guitars, amplifiers, effects pedals and accessories.

Our experienced team of musicians provides knowledgeable, friendly advice both online and through our Birmingham showroom.

When you buy from Fair Deal Music, you benefit from:

• Independent family-run music retailer established in 1987

• Birmingham's largest independent music store

• Over 6,000 Trustpilot reviews

• Expert musician-led advice

• Extensive experience buying and selling pre-owned effects pedals

• Competitive pricing

• Secure online ordering

• Fast UK delivery options

• Large Birmingham showroom

• Friendly customer service before and after purchase

Whether you're choosing your first modulation pedal or expanding an established pedalboard, our team can help you select effects and suitable power accessories to match your setup.

Part Exchange – Trade In. Trade Up. Save More.

Looking to upgrade your existing effects pedals?

Fair Deal Music buys and part-exchanges a wide range of musical equipment, including guitar pedals, amplifiers, electric guitars, basses and keyboards.

Your existing equipment could help towards the cost of this MXR Phase 90.

Contact our team for a no-obligation valuation and discover how much your current gear could be worth in part exchange.

Frequently Asked Questions

What condition is this MXR Phase 90 in?

This pedal is presented in Very Good Pre-Owned Condition, indicating some cosmetic wear consistent with careful previous ownership.

Does this pedal come with a power supply?

No. A power supply is not included.

What power supply does the MXR Phase 90 require?

The standard MXR Phase 90 requires a regulated 9V DC centre-negative adapter with a compatible connector.

How much current does the MXR Phase 90 draw?

The standard M101 model draws approximately 5mA, making it suitable for most conventional pedalboard power supplies.

Can the Phase 90 run on batteries?

Yes. The standard Phase 90 can operate using a single 9V battery.

Is the MXR Phase 90 analogue or digital?

The Phase 90 is an analogue phaser pedal.

What does a phaser pedal do?

A phaser creates a moving, sweeping sound by shifting the phase of selected frequencies and combining the processed signal with the original.

How many controls does the MXR Phase 90 have?

The standard model has a single Speed control and a footswitch for engaging or bypassing the effect.

What does the Speed control do?

It adjusts how quickly the phasing effect moves through its sweep.

Can the MXR Phase 90 produce subtle effects?

Yes. At slower settings, it produces gentle modulation that adds depth and movement without overwhelming the original guitar sound.

Is the Phase 90 suitable for classic rock?

Yes. The pedal is closely associated with classic rock guitar sounds and has been widely used for decades.

Can I use the Phase 90 with distortion?

Yes. It works particularly well with overdrive and distortion pedals, creating expressive sweeping effects.

Should I place the Phase 90 before or after distortion?

Both placements are useful. Before distortion generally produces a more integrated effect, while after distortion can make the phasing movement more pronounced.

Is the MXR Phase 90 suitable for bass guitar?

Yes. The standard Phase 90 can be used with bass guitar, although the audible effect will depend on the instrument and signal chain.

Can I use it with a keyboard?

Yes. It can be used with suitable keyboard and synthesiser outputs, with care taken to avoid excessively high input levels.

Does the Phase 90 have true bypass?

The standard M101 Phase 90 features true hardwire bypass. Other editions may have different specifications.

What is the difference between the Phase 90 and Phase 95?

The Phase 95 combines Phase 90 and Phase 45-style sounds with additional voicing options, while the traditional Phase 90 focuses on one classic phasing circuit.

Is the MXR Phase 90 suitable for beginners?

Yes. Its single-knob operation makes it one of the easiest modulation pedals to understand and use.

Can I part-exchange another pedal towards this MXR Phase 90?

Yes. Fair Deal Music considers effects pedals and other musical equipment for part exchange. Contact our team for a no-obligation valuation.