1982 MXR Phase 100

Model Description:

The bright orange MXR Innovations Phase 100 (model MX‑107) was the ‘big daddy’ of the original MXR Phase range, introduced in 1975. While the compact Phase 45 was a 2‑stage phase pedal producing a mild, subtle vibe‑like sound, the similar‑looking Phase 90 was a 4‑stage phaser capable of generating a more intense and pronounced phase sweep. The Phase 100 goes several steps further, presented in its larger and heavier enclosure, comprising a 6‑stage phase shift and providing users with four selectable waveforms, thereby adding a degree of versatility that the smaller, simpler pedals could not match. A relatively few early Phase 100s came with the widely‑hyped MXR ‘script’ logo, which are now highly sought after collectors’ items. The more ubiquitous later models exhibited the familiar ‘block’ logo from the mid‑1970s onwards. Around 1981/1982, MXR added an LED status indicator and a DC input jack. MXR Innovations ceased production in 1984, sadly cutting off supply completely. Jim Dunlop purchased the MXR brand and the new owners reissued all the original design phasers, including the Phase 100. Price‑wise, the vintage Phase 100 is still relatively affordable and possibly cheaper than a new reissue version or custom shop Phase 90. How long this anomalous situation will last, who knows?

Pedal Description:

This vintage MXR Phase 100 is very much a hefty brick, especially compared to the compact MXR Phase 45 and 90. This example dates from 1982 and has the status LED and DC input, making it much more ergonomic in use than the earlier pedals. The pot codes date to 1982, which is as accurate as one can get, as MXR serial numbers are not definitive. This lovely specimen is in near perfect condition. You have to look hard to see any marks at all, even the foam pad on the baseplate is intact and near unmarked (as is the internal foam – remarkable). I am surprised that its original box and manual weren’t around somewhere. Sound‑wise, I think I’ve found my new favourite old phaser pedal. Up to the point that the Phase 100 joined the family, the Electro‑Harmonix Bad Stone was top dog. The MXR, though has, usurped the EHX at the pinnacle and by some margin. Given that CRAVE Guitars has more phasers than any other type of vintage effect, that is testament to just how good this MXR pedal is. The Japanese brands don’t even come close in my view. The only thing that could have made it better is a ‘mix’ control to blend the dry and wet signal to suit. The 6‑stage analogue modulation phase effect makes a big difference to the clarity and ambience of the sounds produced. The options on show aren’t as subtle as some others but, boy, are they stupendous, much brighter and cleaner than the competition. The result is a more spacey, psychedelic sound than normal. I am usually underwhelmed by phasers and I am generally not one prone to effuse hyperbole but this big little stomp box really is something else and it easily beats even the highly‑regarded Phase 90 in my book. All phasers are not alike, it seems. I am genuinely surprised that it isn’t more highly regarded by musicians and collecterati alike – it deserves more respect as far as I am concerned. I am very impressed. Don’t take my word for it though, why not track one down and try it for yourself?


  • Made in Rochester, New York, U.S.A.
  • MXR ‘block’ logo
  • The ‘Intensity’ knob is a 4‑position rotary switch that selects one of the pre‑set waveform patterns
  • The ‘Speed’ knob controls the rate at which the phase effect cycles
  • Standard footswitch turns the effect on and off
  • ¼” input and output mono jack sockets
  • Red LED status indicator
  • DC power supply input or 9V battery
  • No box or instruction manual

Detail Gallery:

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