The MXR Fat Sugar Drive is an overdrive pedal that carries the Sugar Drive's range of clear and transparent overdrive tones into MXR's classic full-size housing. It is a special edition with a custom pink sparkle finish, and MXR positions it for players who prefer the classic housing's footprint over that of the mini Sugar Drive1.
The controls and the clean blend
The pedal carries three controls, laid out in the table below3.
| Control | What it does |
|---|---|
| Volume | Sets the pedal's output level3 |
| Tone | Shapes the treble character of the drive3 |
| Drive | Sets the amount of drive, blending the clean signal at the start of the sweep1 |
What MXR says sets the Drive control apart is how it works. According to the maker, the Drive control replicates an amp's transition from clean to dirty by blending the clean signal at the start of the sweep, which is where MXR says the pedal's versatility comes from1.
MXR describes the range this gives you in plain terms:
"Together, these elements allow you to serve up everything from a sauced-up boost to full-on blow-tube distortion."
The voltage doubler
Inside the circuit is what MXR calls "a little something called a voltage doubler, which increases overall headroom and opens up the sound of the pedal"1. More headroom gives the overdrive circuit more room before it compresses, which pairs with the clean blend on the Drive control to cover everything from a light boost to heavier distortion tones1.
Bypass and the internal buffer switch
The Fat Sugar Drive ships set to true bypass switching. The manual states: "By default, The M94SE is set to true bypass switching. For buffered bypass switching, remove bottom plate and set the BU"2.
The buffer is not a top-panel control. It lives on an internal switch, so changing it means opening the pedal.
Jim Dunlop's product page walks through it the same way: "just remove the bottom plate and flick the internal Buffer switch, close it up, and get to playing"1. True bypass leaves the pedal's circuit out of the signal path when it is off, while buffered bypass keeps a buffer in line, which some players prefer on larger boards or with long cable runs.
Power
The pedal can be powered in any of these ways1:
- One 9-volt battery, accessed via the underside of the pedal
- The Dunlop ECB003 9-volt adapter
- A Dunlop DC Brick, Iso-Brick or Mini Iso-Brick power supply
How it differs from the Sugar Drive
The Fat Sugar Drive is a variant of the Sugar Drive2. The table below shows where the two differ as MXR describes them.
| Fat Sugar Drive | Sugar Drive | |
|---|---|---|
| Enclosure | MXR's classic full-size housing2 | Mini housing2 |
| Finish | Custom pink sparkle, special edition1 | Standard finish1 |
| Tones | Clear and transparent overdrive tones2 | Clear and transparent overdrive tones2 |
The difference is the enclosure: MXR brought the Sugar Drive's tones "to MXR's classic housing for players who prefer its footprint over that of the mini"2. It is also a special edition with the custom pink sparkle finish1.
Videos
The Music Addict
The Pedal Picassos
Kyle Campbell Guitar
Questions
Is the MXR Fat Sugar Drive true bypass?
Yes, by default. According to the MXR manual, the M94SE is set to true bypass switching as shipped. If you prefer buffered bypass, you can remove the bottom plate and set the internal Buffer switch, then close the pedal back up. That makes it possible to run it either way depending on where it sits on your board and how long your cable runs are.
How do you turn on the buffer in the Fat Sugar Drive?
The buffer is controlled by an internal switch. Jim Dunlop's product page explains that you just remove the bottom plate, flick the internal Buffer switch, close it up and get to playing. The manual confirms the same procedure: take off the bottom plate and set the Buffer switch for buffered bypass switching.
What does the voltage doubler do?
MXR describes the Fat Sugar Drive's voltage doubler as a feature that increases overall headroom and opens up the sound of the pedal. In practice, more headroom means the circuit has more room to work with before the tone compresses, which MXR pairs with the pedal's range from a boosted sound to full-on blow-tube distortion.
How does the Fat Sugar Drive differ from the Sugar Drive?
The Fat Sugar Drive is a variant of the Sugar Drive that carries the same range of clear and transparent overdrive tones but houses the circuit in MXR's classic full-size enclosure instead of the mini housing. MXR positions it for players who prefer the classic housing's footprint over that of the mini. The Fat Sugar Drive is also a special edition with a custom pink sparkle finish.
Sources (3)
- MXR® FAT SUGAR™ DRIVE, Jim Dunlop (jimdunlop.com)
- M94SE.pdf, Jim Dunlop, 2022
- Guitar Pedal X, Guitar Pedal X, 2025-09-03
