The MXR M101GLD 50th Anniversary Edition Phase 90 is a phaser pedal from MXR, dressed in a special edition gold finish to mark the company's 50th anniversary. MXR's manual describes it as a celebration of the Phase 90's legacy "with a special edition finish"1. A single footswitch toggles the effect on and off, with a red LED showing when the effect is on1.
Controls and hooking it up
The M101GLD keeps the Phase 90 layout to two controls plus a footswitch1:
| Control | What it does |
|---|---|
| FOOTSWITCH | Toggles the effect on and off; the red LED lights when the effect is on |
| SPEED | Controls the overall effect rate |
MXR's manual suggests starting with the SPEED control at 12 o'clock, then rotating it clockwise for a faster phase effect or counterclockwise for a slower one1.
Hooking it up is the standard two-cable arrangement: run a cable from your guitar to the M101GLD's INPUT jack, then another from the OUTPUT jack to your amplifier1.
Power
The pedal runs on 9 volts DC and draws 5 mA1. MXR names the Dunlop ECB003 9-volt adapter or an MXR Brick Series power supply as the power options, and it also runs on one 9-volt battery, fitted by removing the bottom plate1.
The M101GLD is a limited edition release. Its single footswitch toggles the effect on and off, and a red LED indicates when the effect is on1.
Where it sits in the Phase 90 family
The Phase 90 line has grown into a family of related pedals, and the gold anniversary edition is one of the more recent additions. Others in the range include the standard Phase 90, the Script Phase 90, the '74 Vintage Phase 90, the Phase 95 mini pedal with its Phase 45 and Phase 90 voicings, the Deep Phase with Speed and Feedback controls, and the EVH Phase 90. For the wider picture, see the Phaser Pedals page.
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Questions
Does the MXR 50th Anniversary Phase 90 take a battery?
Yes. According to MXR's manual, the M101GLD is powered by one 9-volt battery, and you remove the bottom plate to install or replace it. It can also run on the Dunlop ECB003 9-volt adapter or an MXR Brick Series power supply.
Is the gold Phase 90 true bypass?
MXR's manual lists the bypass type as True Hardwire, which is the company's name for its true bypass switching. When the pedal is off, your guitar's signal passes to the amplifier without going through the phasing circuit.
Where do I set the Speed knob to start?
MXR's manual suggests starting with the SPEED control at 12 o'clock. From there, turning it clockwise gives a faster phase effect and turning it counterclockwise gives a slower one.
What power adapter does the M101GLD use?
MXR specifies the Dunlop ECB003 9-volt adapter or an MXR Brick Series power supply. The pedal runs on 9 volts DC and draws 5 mA, so it is a light load on any pedalboard power supply.
How do I change the battery in a Phase 90?
MXR's manual says to remove the bottom plate of the pedal to reach the battery compartment. The M101GLD runs on one 9-volt battery.
Sources (1)
- M101GLD.pdf, Jim Dunlop (jimdunlop.com), 2025
