Premier Guitar features affiliate links to help support our content. We may earn a commission on any affiliated purchases.

Electro-Harmonix Bad Stone Review

The resurrected classic is a bag of unexpected phase treats at a cool price.

If the Electro-Harmonix Small Stone phaser is one of the EHX family’s favorite sons, the original Bad Stone is the brilliant but eccentric cousin who disappeared to some mountain cabin after a failed attempt at prep school.

While EHX produced an early FET-based version, the Bad Stone most players know debuted in 1975 and remained in the EHX line till the early ’80s. It was a relatively ambitious phaser for its time, with six phase-shift stages (the Small Stone had only four) and a switch that enabled players to lock in on a particular point in the phase shift and rock that weird filtered frequency all night long.

Like so many pedals in EHX’s history, the Bad Stone was quirky and original, and it provided something players didn’t even know they wanted. Thankfully, EHX’s quirky urges have never gone away, and now the Bad Stone has been resurrected in a nano-size package with the same functionality as its illustrious, if weird, predecessor. (The only change, according to EHX, is a slightly broader rate control, permitting extra-slow modulation.)

At the speed of a slowly rotating Leslie speaker, the slightly metallic overtones lend a cool peak emphasis almost reminiscent
of ’60s studio flange.

Baby Badness
The Bad Stone was unencumbered by notions of “pedalboard space”—it was as large as the full-sized Big Muff. That may have been a lot of steel for three knobs and a couple of switches, but it provided a killer canvas for graphics. The new nano version still looks sharp, retaining a sweet mix of utility and shag-lined custom-van grooviness. The line drawing of an ugly face that “graced” the original version no longer appears on the enclosure, but it’s memorialized on the PCB’s etching. But despite the extra graphic, the board’s compact layout leaves room for a 9V battery. Everything seems sturdy. My one concern: The footswitch feels a bit stubborn and occasionally engages with a pronounced pop.

The three-knob control set mimics the original. There’s a rate knob, plus a feedback knob that sets the effect’s intensity. The other two controls may be less familiar to the one-knob phaser devotee: the auto/manual toggle “freezes” the phase sweep, while the manual shift knob lets you dial in a specific sweep point, not unlike parking a wah in a particular position. This added function provides cool two-effects-in-one versatility.


Wide-range rate and feedback controls. Manual shift sounds awesome with fuzz.

Slightly metallic and “binary” phase voice.


Ease of Use:




Electro-Harmonix Bad Stone

Dig The Frozen Phase Craze
Players who use a wide range of phase rates will find much to like here. At low feedback levels in particular, this can be a wonderfully subtle but rich effect, especially for slow chord arpeggios, atmospheric lead lines, and even chugging quarter-note rhythms. Increasing feedback levels can be tricky at these slow speeds. I found the best fits to be feedback settings between noon and 2 o’clock (which, incidentally, most closely approximate the richness of a vintage Small Stone). Feedback levels outside these marks often highlighted the more metallic, less contoured aspects of the Bad Stone’s phase voice at all rates.

Thankfully the binary qualities of the Bad Stone’s voice work best at the faster rates where phasers are most often employed. At the speed of a slowly rotating Leslie speaker, the slightly metallic overtones lend a cool peak emphasis almost reminiscent of ’60s studio flange. And while traditionalists might cringe, cranking the feedback can guide pedestrian faux-Floyd riffs in unexpected directions.

The surprise treat is the manual shift function. While it can have a thinning effect on clean tones, it sounds super hip with fuzz and high-gain overdrive. The filtering characteristics are different from a typical parked wah: There’s less quack and immediate pick attack, depending on which phase region you isolate. But it’s also a less familiar effect, and the knob’s range makes it easier to dial in a specific frequency to suit a given part or song.

The Verdict
The multi-faceted Bad Stone offers a lot of phaser for around 73 bucks. It may not have the richness and gently contoured harmonic nuance of a vintage Small Stone, but at the right feedback settings, it gets very close. The feedback control is useful for moving from vintage flavors to more experimental phase tones that leverage the Bad Stone’s metallic resonance, while manual shift mode transforms the Bad Stone into a unique filter. It’s is a powerful and intriguing sonic tool at a great price.

Watch the Review Demo: