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MXR M287 Sub Octave Bass Fuzz Review

The lethal combination of fuzz and an octaver comes to life through this powerful yellow box.

Recorded using PreSonus AudioBox iTwo interface.
Clip 1 - Fuzz section mode set with flat mids. Gain at 1 o'clock, fuzz at noon, bass at noon, treble at 11 o'clock. Octaver off, dry set at 10 o'clock, and mid+ dial set at 10 o'clock.
Clip 2 - Fuzz section mode set with flat mids for first half of clip before switching to scooped mids voicing. Gain at 2 o'clock, fuzz at 2 o'clock, bass at noon, treble at noon, sub octave at 11 o'clock, dry at 9 o'clock, and mid+ dial set at 7 o'clock.

As modern music has evolved, so has the demand for thicker and fuller bass tones. Luckily for us bassists, there’s a wealth of tools to help accomplish this, including compression, DI blending, fuzz and overdrive, or parametric EQ’ing. Regardless of what’s used, the key to effective thickening relies a lot on how well these tools are blended together, which brings us to MXR’s M287 Sub Octave Bass Fuzz. It combines two of the most popular thickening tools for bassists—fuzz and lower-octave doubling—with straightforward blending and EQ controls.

In the end, what grabbed my attention most was how focused and muscular the fuzz managed to be under heavy saturation.

The all-analog Sub Octave Bass Fuzz is built with the same rugged standards MXR pedals are known for. Its enclosure is as tough as they come, the controls offer substantial friction when turned, and its footswitches respond to stomping with a reassuring mechanical snap. Located on the left, the fuzz section’s controls include gain and fuzz, as well as a small push-button to select between two different voicings. There’s also a 2-band EQ for additional fine-tuning. The amount of single-octave-down sub octave is governed by a single control on the right side and the effect sports footswitchable bypassing. Lastly, there’s a volume knob for the unaffected dry signal that’s tied to a midrange-boost control for adding extra cut and punch to the dry tone.


Fierce-sounding fuzz that’s unique in the MXR family. Smooth, colossal-sized lower octave. Simple and effective controls.

Fuzz is occasionally noisy at higher gain settings. Mid-scooped fuzz mode suffers from a volume drop.


Ease of Use:




MXR M287 Sub Octave Bass Fuzz

Run Silent, Run Deep
Pairing a Fender P with a Mesa/Boogie 400+ pushing a Mesa PowerHouse 4x10, I started exploring the fuzz effect by setting its EQ and volume controls at noon, the fuzz-mode button switched to its flattened-midrange mode, the gain at 3 o’clock, and the dry knob all the way down. The result was a huge tone under an avalanche of gain that delivered punchy lower mids, ribcage-rattling lows, and a pleasingly smooth top end.

With the gain up high, the pedal produced a noticeable wash of background noise between notes—enough that it might compel you to dig around for your long-forgotten noise gate. In the end, however, what grabbed my attention most was how focused and muscular the fuzz managed to be under heavy saturation. For a fuzz pedal with so much gain on tap, its clarity and note definition was impressive. Dialing in a more moderate 10 o’clock gain setting and playing on the lower registers enabled the low end to relax and breathe, and any and all background noise was silenced.

The secondary fuzz mode introduced a tighter low-end with a drastic midrange cut. Though I had to perform some quick volume and EQ adjustments to compensate for the mode’s lower output volume, it was the perfect voicing for staccato riffing, galloping thrash-metal triplets, and any application that demanded tight-fisted playing while remaining bone-crunchingly heavy.

Engaging the sub octave and setting it at 11 o’clock unfurled a mammoth-sized foundation that shook the walls and floor. It was smooth-sounding and powerful, and unless my amp was incapable of producing any low end on its own, I can’t imagine ever needing to turn the control up higher. The octave’s monophonic tracking worked flawlessly all along the fretboard’s lower registers and only glitched occasionally if I threw in a chord. Removing the fuzz revealed more of the octave effect’s bubbly lows and rubber-band-like mids, and using the mid-level dial to mix in an additional range of mids produced a beautifully complex, full-bodied clean.

The Verdict
The Sub Octave Bass Fuzz is a no-brainer option for bassists wanting a viable way to liven up their tone with little fuss or muss. It’s capable of generating varying degrees of warm and subtle grind to crushing fuzz and synth-like growl—all of which are easy to dial in using its set of simple controls. And if you’re pondering bang for buck, don’t forget that you can run the fuzz or sub octave solo, so you’re effectively getting two great-sounding effects in one.

Watch the Review Demo: