In the long list of bass effect pedals that constitute a well-rounded collection, wah-wah is not as universally beloved as some—perhaps because it’s more commonly associated with guitar, or maybe because inexperience with wah limits some players’ awareness of its diverse potential. I, however, am a big fan of wah for bass, and not because I love the rhythmic rocking back-and-forth that some may commonly associate with the effect. Rather, a well-designed bass-specific wah can be a powerful tone-sculpting device, substantially altering the instrument’s timbre to dramatic effect. The bass wah market is not an overcrowded space and new bass wahs are rare, so I was excited to check out the new Rewah-PRO from California’s Mission Engineering. It’s cleverly designed and specially voiced to work with the low register.
The crucial electronic ingredient of most wah-wah pedals is an inductor, a discrete component that in this context is part of a circuit that creates a resonant peak in the audible frequency range. When combined with a potentiometer (in this case, controlled by your rocking foot), this resonant peak is sweepable, increasing the gain around a given frequency and filtering out frequencies above the peak. Given the essential impact of the inductor on a wah’s personality and tone, there is much debate among the wah cognoscenti about various inductors; it is to guitar-discussion forums what “which oil should I use?” is to car-discussion forums. When it comes to bass, the quality and size of the inductor is a substantial contributor to its efficacy, given the instrument’s low-frequency zone. Knowing this, Mission Engineering spec’d one of the beefiest inductors I’ve seen in a wah, claiming it helps prevent unwanted saturation and better contends with the instrument’s unique requirements.
The Rewah-PRO has a few other tricks up its sleeve. When you pop open the bottom cover, revealing the neatly designed through-hole printed circuit board, there’s a quartet of dipswitches that allow further control of the wah’s character. The first increases the gain at the input transistor, resulting in a touch of pleasant overdrive (although the degree depends substantially on the output level of your bass), while the others shift the pedal’s frequency response. Even though I found myself favoring the pedal’s stock sound, it’s cool to have a bit of extra flexibility on hand. I was also impressed with the Rewah’s construction. The true-bypass pedal uses a robust switch, and all the jacks, hardware, and associated electronics seemed up to the rigors of the road.
I used the Rewah-PRO with a variety of basses, including stock passive Fender-style basses and some hotter active instruments from my collection. It’s an excellent-sounding wah, voiced ideally for bass. Its low-noise was welcome, as was its potent filtering effect. As I alluded to earlier, wah-wahs aren’t just for rhythmic rocking; they can be left on in a static position for a dramatic timbre shift or, my favorite, slowly moved from low-to-high to emulate the sound of a synthesizer’s lowpass-filter’s cutoff frequency being gradually moved. With some distortion and octave, these kinds of gradual timbre changes can add great dramatic effect to transitions and any other sort of synth-emulating use-case one might dream up.
While it isn’t cheap, the Mission Engineering Rewah-PRO does everything one could want from a bass wah, and then some. If you’ve never explored wah for bass, there are few better options out there.
Pros Excellent construction; flexible design; well-tuned frequency response
Bottom Line Anyone on the hunt for a superb-sounding bass wah should include the Rewah-PRO Bass on their audition list.
Power 9 volts via external jack or 9-volt battery
Made in U.S.A.