Review: Boss VO-1 Vocoder

Four fun vocal effects for guitarists and bassists.
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Although Boss offers a wide variety of vocal-effects processors, it hasn’t made a portable vocoder designed for the pedalboard—until now. Housed in the familiar single-pedal form factor, the VO-1 provides four effects that are optimized for use with electric guitar and bass—two vocoders, a talkbox, and a synthetic choir.

Because your voice will be the control source, the VO-1 includes an XLR input designed for dynamic mics. (Phantom power for condenser mics is not provided.) The onboard sensitivity switch provides high and low settings to increase compatibility with nearly any dynamic mic you’ll run across. I plugged in a Shure SM58 with the VO-1’s sensitivity set to Low and had plenty of gain for the mic to do its job. Overall, the mic input provides a surprising amount of dynamic control over the effects.

Power the VO-1 Vocoder using the included 9V battery or a Boss PSAseries AC adapter (sold separately). The vocoder modes are called Vintage and Advanced, the former providing a warm, late-’60s vibe with a low number of frequency bands, and the latter yielding more complexity and greater phonetic clarity. The VO-1’s talkbox emulation is very musical and works well on guitar and bass (and it doesn’t require you to stick a tube in your mouth like the original does).

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The VO-1’s controls include output level and a Blend knob for setting the wet/dry mix. The Tone control can be used to brighten or darken the processed sound, while the Color knob alters the vocoder’s spectral content to change the “gender” of the effect.

In Talkbox mode, the Color knob adds distortion as you turn it clockwise. With the right setting, you can coax a bit of feedback from your guitar depending on the note you play, the pedal’s output level, and the intensity of your voice. Moreover, by changing the pitch of your voice—such as singing in falsetto—you can further modify the spectral response in all three modes.

Intended to provide a vocalensemble effect, Choir mode doesn’t need the mic input as a trigger. To get a sense of its tone, imagine having several cocked-wahs on simultaneously, each with a different highlighted frequency. The resulting formant- like filter produces a synthy-sounding “ah,” which the Color knob changes from a low male-like timbre to a higher, more nasal sonority. To achieve the most convincing choral-like sound, however, I used volume swells with a touch of reverb or delay.

The VO-1 also includes send and return jacks for routing the direct sound of your instrument through other effects. Depending on the Blend knob’s setting in the vocoder and talkbox modes, you’ll hear your unprocessed instrument on its own (with or without insert effects) until you talk into the mic; then the VO-1’s processing appears. The trick in a high-volume performance situation is to get a strong direct signal with the Blend knob, but not making it so loud that it bleeds into the mic and triggers the vocoder/talkbox effect.

The VO-1’s main competitors are the Electro- Harmonix vocal processors, which cost a bit less and offer additional features (pitch correction, reverb, phantom power). On the other hand, the VO-1 has insert I/O, as well as a simple interface and smaller footprint than EHX’s larger models.

But most importantly, the VO-1 sounds great and is a blast to use. And once you start using it, it’s hard to stop. You’ve been warned!


Mic input with sensitivity- level switch. Effects insert for dry signal. Talkbox effect offers distortion.


Pricey compared to other Boss pedals this size.

$249 street