MXR Badass Modified OD

The MXR Custom Badass Modified O.D., model number M77, is an overdrive pedal from MXR that takes a classic overdrive circuit and adds two modern modifications: a 100Hz cut and boost control and a Bump switch¹. It sits in the low to mid-gain range, which makes it a pedal for pushing an amp into breakup or adding grit on top of a clean tone rather than delivering high-gain distortion on its own. MusicRadar's review team called it "an excellent low to mid-gain overdrive with wide tonal options and rock-solid MXR build"².

The pedal was announced at the Winter NAMM show in January 2012³ and came from the same MXR Custom Badass team behind the Custom Badass '78 Distortion released the year before⁴. Vintage Guitar described it at introduction as "an overdrive circuit with modern modifications"⁵.

What it does to your sound

The core of the M77 is a classic overdrive circuit, the kind of design players already know from the long history of the effect, but MXR modified it with the two extra controls that give the pedal its name¹. In its normal mode, with the Bump switch off, MusicRadar found the sound "pretty transparent," meaning it adds gain without heavily re-voicing your amp's character². That puts it in the same family as pedals players reach for when they want their base tone preserved, just driven harder.

Flip the Bump switch and the character changes. The switch engages an alternate EQ voicing that boosts the lows and mids¹, and MusicRadar's reviewers heard that as Tube Screamer territory, with the boosted low mids pushing the sound forward for more sustain². In effect, one pedal covers two overdrive philosophies: a flatter, more transparent voice and a mid-forward, sustain-heavy one.

The controls

Four knobs and a small switch handle everything. Three of them are the standard overdrive set that Premier Guitar called "practically de rigueur" for the effect⁷, and the other two controls are where the M77 departs from a stock circuit.

Premier Guitar's reviewer noted that the four small knobs and the miniature Bump button "look a little less robust than the big rubber knobs that once graced MXR" pedals of the past, a cosmetic observation rather than a report of anything failing⁷.

The 100Hz knob

The 100Hz control is a cut and boost knob centered on that frequency. MXR's own description is that cutting it "allows for a more focused EQ" while boosting it gives "a beefier tone"¹. In practical terms, MusicRadar put it as a way to "really fatten up the bottom or make it lean and mean"², which is useful for matching the pedal to different amps and guitars: a single-coil guitar through a small combo might want the boost, while a bass-heavy rig might want the cut.

Premier Guitar singled this knob out as the distinguishing feature, calling it "a big part of what makes the Badass different" and finding that it "has remarkable shaping power through the whole range of gain levels," with particular effectiveness in roots-rock settings⁷.

The Bump switch

The Bump switch is a low and mid-range boost⁴. MXR describes it plainly: "The Bump switch engages an alternate EQ voicing that boosts the lows and mids"¹. Guitar World's NAMM demo reported the same behavior when the pedal launched⁸.

For a player, the switch is effectively a second voicing. Off, the pedal runs its normal, more transparent EQ. On, the lows and mids come up, which MusicRadar found pushes the sound forward and adds sustain, in the direction of a Tube Screamer's mid hump². Because it is a switch rather than a knob, the change is instant and consistent, something you can set for a whole song or flip mid-lead.

What reviewers said

Published reviews were positive on both sides of the Atlantic press.

• MusicRadar: "an excellent low to mid-gain overdrive with wide tonal options and rock-solid MXR build," with "superb tonal versatility" listed among its strengths².
• Premier Guitar: "at just around a hundred bucks, it's a contender for the performance-to-value crown in the overdrive division"⁷.

The one criticism on record is the cosmetic note about the small knobs and miniature Bump button looking less robust than older MXR hardware⁷. No review disputes the pedal's build quality overall, with MusicRadar explicitly calling it rock-solid².

Videos

Click to load

Click to load

Click to load

Questions