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Mu-FX Boostron 3 Review

Mu-FX Boostron 3 Review

An inspired combination of drive and compression effects in a beauty of a pedal from a stompbox legend.

When the Stompbox Hall of Fame is built, the wing dedicated to Mike Beigel and Mu-Tron will be a place of pilgrimage to players and fellow builders alike. To enthusiasts who savor pedal aesthetics, the corridors of Mu-Tron will celebrate the coolest-looking stompboxes ever built. For builders, it will be a place to toast the inventive spirit of Beigel and his associates—engineers who combined strong musical sensibilities with ace, often irreverent engineering chops.

Stompbox fans from both camps will get a kick out of the Boston 3 from Beigel’s newer pedal-building concern, Mu-FX. Born of a collaborative effort with software specialist/working musician Rand Anderson and longtime Beigel design partner Richard Lingenberg, it's a cool amalgamation of Alembic Strat-o-Blaster-, Orange Squeezer-, and RAT-inspired circuits in an all-in-one drive that reflects the spirit of inspired recombination that defined Mu-Tron effects, from the Volume-Wah to the Bi-Phase. It might also be one of the sturdiest and handsomest effects boxes you ever stomp on.

Muddy neck humbuckers and thin single-coils can be transformed with the effect.

Built for the Beyond
Although the Boostron 3 is beautiful, you can sense the function-is-king motivations behind the design from a cursory inspection. The hefty enclosure is crafted from heavy-gauge aluminum and steel and has the reassuring mass of a stone without feeling clunky. For a three-function pedal, it’s relatively compact. But what you take away most is that the pedal is likely to outlive the cockroaches in the event of an apocalypse. The jacks and switches all feel robust and securely fashioned. The small toggles—situated as they are below the top of each knob—are all safe from accidental switching and errant blows from a boot. Opening the pedal up reveals two tiered circuit boards that are as tidily wired as you’ll ever see. And while the jacks are board-mounted, the whole circuit board array feels well insulated from the shock of transport and stage blows by the rock-solid enclosure.

Operating the unit is intuitive and tactilely satisfying, thanks to the perfect resistance of the potentiometers and the rubber knobs' touch-sensitivity. It feels like a precision lab instrument more than a stompbox. And that multi-colored paint scheme that makes the Boostron 3 look like it was lifted from the deck of the original Starship Enterprise? It not only looks killer, but also visually groups the controls according to function, making an otherwise tricky control set a breeze to navigate. You’ll still need practice to sort out the precise function of some knobs and switches, and some labels are less than clear (the mode switch on the slacker effect is particularly confusing), but once you’re acquainted the pedal becomes a breeze to operate.


Robust, bulletproof build. Effects loop.

Sensitive controls and hot extremes can make the pedal feel twitchy and explosive.


Ease of Use:




Mu-Fx Boostron 3

A Tasty Trio
There’s nothing earthshakingly revolutionary about the Boostron’s circuitry. The LM 308N-based RAT and Dan Armstrong Orange Squeezer have been copied, with varying degrees of success, elsewhere. The most unusual component of the Boostron’s makeup is the blaster circuit, which is based on the jack-mounted Alembic Strat-o-Blaster preamp that helped define Jerry Garcia’s ’70s tones as installed in his famous “Alligator” Stratocaster. But it is the somewhat unlikely and inspired combination of the three effects—and the way they interact—that make the Boostron 3 so magical.

The booster is activated via a mini toggle, and the squeezer and slacker have dedicated footswitches. But Mu-FX may have understood how rarely you’ll want to turn this excellent boost off once it’s on. The boost control has scads of range—from a subtle bump that has a sweet thickening effect across the frequency spectrum to a significant kick in output that can sound downright (and delightfully) scathing when you add in generous doses of the bright control. Muddy neck humbuckers and thin single-coils can be transformed with the effect. It’s simple and satisfying to use and I turned it off infrequently.

The squeezer compression section, which is based on the celebrated but somewhat underrated Dan Armstrong Orange Squeezer, is a beautiful study in simplicity. While not always subtle, it doesn’t impart a lot of extra color or squash every trace of dynamics in trade for sustain. Instead, the extra sustain and compression sound organic, touch sensitive, and even amp-like at lower compression settings. The available boost is significant. In fact, it makes a great second clean boost complement to the booster when set up right.

The slacker side of the pedal yields many great overdrive and distortion tones, though it isn’t always easy to wrangle. Where an old 3-knob RAT enables you to dial out harshness quickly via the filter knob—effectively replaced here by the 3-position bass switch—and fine tune using the volume and distortion controls, the slacker effect takes a bit more work. The big difference between the slacker and RAT is the switchable clipping, which yields profound differences in output and distortion characteristics depending on the setting. Depending on your guitar and amp, the single diode and LED diode modes (“exp” and “dist” respectively) can sound quite hot and explosive and you’ll have to be careful if you’re also using hotter booster and squeezer settings. Such extreme sounds can be enormous and rich with humbuckers and a tweed-style amp. With a Twin and a Stratocaster they were dangerously trebly. The upside? The Boostron gives you the range to explore a vast swatch of tones between harsh and mellow extremes. And when you get a feel for the more seamless interactions that are possible between the slacker and the other two circuits, you’ll start to discern an almost studio-like capacity to shape distortion tones.

The Verdict
Although it seems simple in many respects, the Boostron 3 is not exactly an immediately satisfying plug-and-play affair. It has a distinct hi-fidelity quality at many settings that punishes sloppy technique and ill-chosen guitar and amp combinations. That sensitivity can make it seem twitchy in live settings if you haven’t spent a lot of time with the pedal. In the end, though, the expansive range and resulting nuance make the Boostron 3 a remarkable and deeply satisfying cross of precision, science, and savagery that can make you feel like a tone surgeon.