The MXR Phase 45 is a two-stage phaser made by MXR, released two years after the Phase 90 as its smaller sibling123. Where the Phase 90 uses four stages, the Phase 45 uses two, which gives it a gentler, less dramatic phasing effect. JHS Pedals describes it plainly: "It has less stages than the Phase 90. This is a less dramatic phasing sound."4 The original was short-lived and discontinued, and it has since returned in limited reissue form as the MXR '75 Vintage Phase 4556.
What it does and how it is controlled
The Phase 45 has a single control, the Speed knob. Pedal of the Day describes its range as wide: "The sweep of the lone Speed knob is fairly widespread as well, going from slow and pulsing to ultra-fast, almost UniVibe" territory3. Dunlop says the two-stage design "offers up its subtle and musical voice via hand-matched FETs and hand-wired circuit board" on the reissue5.
The circuit is FET-based, like the Phase 90. Function f(x) lists the Phase 45 alongside the Phase 90 and the Boss PH-1 among commercial examples of JFET-based phase shifting, and MusicRadar's Alex Lynham confirms that "the MXR Phase 45 and Phase 90 are FET-based"78. General Guitar Gadgets, which offers a Phase 45 project for builders, calls it "an under-rated and a most excellent phase shifter" and says it is "sometimes wrongly written off as 'too subtle'"9.
Phase 45 versus Phase 90
The two pedals share a family and a circuit approach but differ in depth of effect:
| Phase 45 | Phase 90 | |
|---|---|---|
| Stages | Two52 | Four2 |
| Character | Subtler, less dramatic34 | Deeper, more pronounced |
| Released | Two years after the Phase 90123 | First |
Tim Mahoney, speaking to Premier Guitar, put the difference in one line: "The 45 is a two-stage phaser, while the 90 is a four-stage unit."2 Pedal of the Day notes that "The Phase 45 was preferred by some over the other classic MXR phaser, the Phase 90, due to its more subtle sounds"3.
History and versions
MXR released the Phase 45 two years after the Phase 9010. The original run was short-lived, and Aion FX describes it as "a short-lived 'little brother' to the [MXR Phase 90]"6. The pedal has a documented country connection: Premier Guitar's review of the Fender Waylon Jennings Phaser refers to Jennings' "2-stage Phase 45"1.
Versions a player is likely to come across:
- Original 1970s Phase 45: discontinued, true bypass, no LED, now a collector's item36
- 2010 script reissue: priced at $99 at the time, per Guitar Pedal X11
- MXR '75 Vintage Phase 45: a limited-edition reissue from the MXR Custom Shop with hand-matched FETs and a hand-wired circuit board, described by Dunlop as reproducing "the rare little brother of the Phase 90 to exacting" standards; marked as a legacy product no longer in production5
- MXR Phase 95: a 2017 mini pedal that includes a Phase 45 mode by bypassing two of the phase stages6
Both the original Phase 45 and the '75 Vintage reissue are out of production. Dunlop marks the '75 Vintage Phase 45 as "LEGACY PRODUCT / NO LONGER IN PRODUCTION"5.
What reviewers said
Pedal of the Day's review of the vintage script version calls it "This true piece of phaser history" and praises the faithfulness of the reissues, "right down to the lack of LED"3. Guitar Pedal X included the Phase 45 among its selection of one-knob two-stage phasers, alongside the DOD 201 Phasor, the Electro-Harmonix Small Stone and the JAM Pedals Ripple11.
Prices
| Version | Price | Date and source |
|---|---|---|
| '75 Vintage Phase 45 reissue | Street $9912 | Premier Guitar, 2026 |
| 2010 script reissue | $99 at the time11 | Guitar Pedal X |
| Original, pristine condition | Possibly $800 to $100011 | Guitar Pedal X, 2024 |
Guitar Pedal X's Stefan Karlsson wrote that "if you try to acquire an original Phase 45 in pristine condition - you might be paying somewhere between $800 and $1000"11.
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Questions
What is the difference between the MXR Phase 45 and the Phase 90?
The Phase 45 is a two-stage phaser while the Phase 90 is a four-stage unit, as Tim Mahoney put it in a Premier Guitar interview. Fewer stages means a less dramatic phasing sound, and Pedal of the Day notes the Phase 45 was preferred by some players over the Phase 90 for its more subtle sounds. Both circuits are FET-based, and the Phase 45 arrived two years after the Phase 90.
Is the MXR Phase 45 discontinued?
Yes. Aion FX describes the original Phase 45 as a short-lived little brother to the Phase 90, and Dunlop's product page for the '75 Vintage Phase 45 reissue marks it as a legacy product no longer in production. The pedal has appeared again over the years in limited reissue form, but it is not a current catalog item.
Is the MXR Phase 45 true bypass?
Pedal of the Day's review of the vintage script version describes it as a true piece of phaser history and identifies it as true bypass. The review also notes the reissues are meant to be faithful recreations of that original, right down to the lack of an LED indicator.
How many stages does the Phase 45 have?
Two. Dunlop describes the '75 Vintage Phase 45 as a phaser with two stages of phasing, and Premier Guitar has referred to Waylon Jennings' 2-stage Phase 45. By comparison, the Phase 90 is a four-stage unit.
Does the MXR Phase 45 have an LED?
No. Pedal of the Day's review of the vintage script version points out the lack of LED as part of what makes the original what it is, and says the reissues are supposed to be faithful recreations right down to that missing indicator.
How much does an original MXR Phase 45 cost?
Guitar Pedal X's Stefan Karlsson wrote that an original Phase 45 in pristine condition might cost somewhere between $800 and $1000. By comparison, the 2010 script reissues were $99 at the time, and the later '75 Vintage Phase 45 reissue carried a $99 street price per Premier Guitar.
Sources (12)
- Fender Waylon Jennings Phaser Review, Premier Guitar, 2023-11-06
- Tim Mahoney’s Top Five Oddball Pedals, Premier Guitar, 2014-10-20
- MXR Phase 45 Vintage Script Phaser, Pedal of the Day, 2020-09-24
- HOW MXR PEDALS BECAME LEGENDARY, JHS Pedals
- MXR® '75 VINTAGE PHASE 45, Jim Dunlop (jimdunlop.com)
- Apex JFET Phaser / MXR Phase 45, Aion FX, 2024-04-19
- Guitar Phaser Pedal Types: JFET, Optical, OTA, and Others, Function f(x), 2022-03-18
- Warm Audio Mutation Phasor ll review, MusicRadar, 2023-09-08
- MXR™ Phase 45™ Clone: DIY Phaser Kit, PCB & Schematic, General Guitar Gadgets, 2014-05-18
- MXR® PHASE 95, Dunlop (www.jimdunlop.com)
- Guitar Pedal X, Guitar Pedal X, 2024-09-09
- MXR '75 Vintage Phase 45 Pedal Review, Premier Guitar, 2010-10-20
