While Matthews Effects builds stompbox staples like overdrive and fuzz, it seems the company’s real fascination is the weirder, wobblier side of the effects equation. Their latest, the Chemist, seems to confirm as much. It’s built around three digital effects: chorus/vibrato, octave, and phaser. It also features a switching system so you can assign the effects to one of two identical control sets and switch between them. The resulting textures, and the differences between them, can be subtle or radical—making the Chemist a capable and often unusual sounding multi-effect that doesn’t take up a lot of pedalboard space.

Mixing Compounds
With six knobs, two 3-way switches, and two stomp switches, the Chemist looks trickier than your average compact modulation machine. And while it certainly doesn’t require a PhD to operate, a thorough reading of the instruction manual will help you command the oddly named controls and concoct tones faster than you might going in blind. That said, it’s fun to find your way through the many compound sounds you can mix with the Chemist.

The control set is built around two identical rows of knobs. And because the knobs vary in function depending on the effect you assign to the row, Matthews uses chemistry-themed names to denote their purpose. The formula knobs alter the resonance of the phaser, the depth of the chorus, or remove or add low octave relative to the high octave. The reaction knobs control wet/dry signal mix. Catalyst controls the speed of the phaser and chorus or the high-octave mix. Functions and effects are assigned by the two toggles at the top of the pedal.

Phaser tones are especially varied. I was even able to cook up a phaser-based approximation of Jerry Garcia’s envelope filter sounds from Shakedown Street.

The left-hand switch selects the effect type for the top row, while the right-hand switch selects the effect for the bottom row. You’ll have to get used to the Periodic Table of Elements-derived shorthand used to identify the toggle modes. Lithium (Li) corresponds to the octave effect, cobalt (Co) corresponds to chorus/vibrato, and irridium (Ir) corresponds to the phaser. You’ll also have to remember that the left and right switch work in mirror image to each other. Overall, the Chemist does not use the most intutive labeling. But with a little practice, managing the functions becomes second nature.

Switching between the two rows is performed using the alt switch, which is the topmost and taller of the two foot switches. The shorter switch is the master bypass. There’s also a jack on the left side of the unit, if you want to use your own aftermarket switcher to change between the two effects. The Chemist only accepts a 9V barrel adaptor. It’s packed to the gills with circuitry and there’s no room for a battery input.

Busy in the Lab
Once you have navigation of the controls down, the Chemist serves up really interesting tones, from vintage-flavored to otherworldly. Phaser tones are especially varied. I was even able to cook up a phaser-based approximation of Jerry Garcia’s envelope filter sounds from Shakedown Street, with the depth (formula) and speed (catalyst) controls around 10 o’clock. The phaser can also be incredibly vocal and almost flanger-like—especially when you push the resonance. Increasing depth creates intense swirling effects that become extra metallic with the addition of resonance. But while some of these effects verge on too extreme for practical use—and in some cases betray digital origins—you can push them to the background a bit using the wet/dry mix and employ them as complementary textures for clean rhythm or lead tones.



Ability to switch between variations on the same effect or different effects entirely. Compact design.

Cryptic control names. Octave sounds colored by modulation.


Ease of Use:




Matthews Effects the Chemist

The Chemist’s chorus tends to sound lusher, deeper, and dreamier than your standard digital chorus fare. It also sounds fuller on the lower end. Bringing in more dry signal tends to favor the vibrato textures in the effect. And with a Stratocaster in hand, I found a nice chorus/vibe blend for “Shine On You Crazy Diamond”-style sounds. Adding a fuzz to this mix delivers very nice Hendrix flavors—especially with the formula control around 9 o’clock. Cranking it much higher, however, can highlight extra low-end presence. And in tandem with fuzz, the extra bottom can overpower some of the nuance in the modulations.

The octave is excellent for POG- and Whammy-style organ effects, and traces of 12-string color when you add the right amount of upper octave. (A little tends to go a long way, by the way). Octave-down tones, meanwhile, are cool for doubling or harmonizing with bass parts. All of the octave sounds are colored with modulation that sounds somewhere between a fast chorus and tremolo. It would be nice if you could remove the modulation entirely, but that might have required an additional control when knobs and switches are already packed pretty tight on the pedal’s surface. (Perhaps future versions can use an internal toggle). That said, the modulated octave tones can sound great—especially with a little delay and reverb. And in a dense mix, you can be a pretty effective stand-in for an organ fluttering through a Leslie.

The Verdict
With the ability to switch between radically different effects—or just subtle variations on the same one—the Chemist is surprisingly versatile. It works particularly well with amplifiers sporting higher headroom, where you can hear the interplay between various octave settings and the range in the modulation effects. (Smaller amplifiers tend to get a little overburdened by lower-octave settings.) Otherwise, the Chemist works equally well with many pickup and guitar types. Better still, it’s a viable choice for the player who moves between classic rock and chaos—delivering variation and value in a pedal that wont take up acres of space.