The MXR M251 FOD Drive is an overdrive pedal from MXR that puts two overdrive circuits in one compact MXR-format housing. One side is a High Gain channel, the other a Crunch Gain channel, and a front-panel Blend knob lets you mix the two sounds anywhere between them12. The manual describes it as supplying "the sonic power of two highly sought-after amp stacks in a single housing"1.
Guitar World's reviewer, Trevor Curwen, found that both sides have the flavor of a nicely cranked stack, with each channel individually offering a range of useful tones for rhythm playing or saturated leads2.
Two overdrive channels you can blend
The core idea of the FOD Drive is running two overdrive voices at once and balancing them against each other. The High Gain channel sits on the right of the pedal, with its gain controlled by a front-panel knob. The Crunch Gain channel sits on the left, and its gain and volume are set by internal trimmers, described by Guitar World as "set-and-forget" adjustments for players who want to deviate from the factory settings2.
A front-panel Blend knob sets the mix between the two sounds2, which the manual describes as setting the mix of the High Gain and Crunch Gain circuits1. A SCOOP switch on the panel selects flat, scooped, or boosted midrange frequencies, with the up position giving a flat response1.
Guitar World's verdict on the concept:
"The FOD does a neat job in combining two different but complementary overdrive flavours and the controls you need to blend them."
The controls: Blend, Gain and internal trimmers
The control layout splits between what you see on the outside and what you adjust inside the box21.
| Control | Location | What it does |
|---|---|---|
| BLEND | Front panel | Sets the mix of the High Gain and Crunch Gain circuits1 |
| OUTPUT | Front panel | Sets overall volume1 |
| SCOOP switch | Front panel | Selects flat, scooped, or boosted midrange frequencies1 |
| High Gain channel Gain | Front panel | Sets the gain of the High Gain channel2 |
| CRUNCH GAIN | Internal | Sets the intensity of the Crunch Gain circuit's overdrive1 |
| CRUNCH VOLUME | Internal | Sets the output level of the Crunch Gain circuit1 |
The internal trimmers mean the Crunch Gain channel can be dialed in once to match your amp and then left alone, while the external controls handle the day-to-day adjustments. The manual also lists an input impedance of 770 kΩ and an output impedance under 900 Ω1.
Where it fits in the MXR line
The FOD Drive is a variant on an existing MXR idea. MXR's Dookie Drive was based on the rig of modified Marshalls that Billie Joe Armstrong used on Green Day's third album, and Guitar World describes the M251 FOD Drive as designed to do the same job, "albeit with no artist affiliation"2. In other words, it aims at the same two-amp-stack sound without the Green Day tie-in.
If you are comparing the two, the FOD Drive is the artist-free version of the Dookie Drive concept. The Dookie Drive carries the Billie Joe Armstrong affiliation; the FOD Drive does not2.
Within MXR's broader overdrive range, the FOD Drive sits alongside pedals like the GT-OD, the Sugar Drive and the Duke of Tone, but its two-channel blend design is what sets it apart from single-voice overdrives in the line21.
Powering it
The FOD Drive runs on 9 volts DC, drawing 11 mA1. You can power it either from a 9V DC adaptor, which is not supplied, or from one 9-volt battery installed by removing the bottom plate12. The 11 mA draw is modest by pedalboard standards, so it will not put heavy demands on a multi-output power supply.
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Questions
Is the MXR FOD Drive true bypass?
Yes. The manual lists its bypass as True Hardwire, and Guitar World's review describes it as true bypass, so your clean signal passes through untouched when the pedal is off.
Does the MXR FOD Drive take a 9V battery?
Yes. It runs on one 9-volt battery, which you install by removing the bottom plate, or on a 9V DC adaptor, which is not supplied with the pedal.
How much current does the MXR FOD Drive draw?
It draws 11 mA, which is low enough that it will not strain most pedalboard power supplies or a daisy chain.
Is the FOD Drive the same as the Dookie Drive?
Not quite. Guitar World describes the FOD Drive as following the same concept as the Dookie Drive, which was based on Billie Joe Armstrong's modified Marshalls, but the FOD Drive has no artist affiliation.
Sources (2)
- M251.pdf, Jim Dunlop, 2020
- MXR FOD Drive review, Guitar World, 2021-04-08
