Any effect can color a guitar’s personality and language. But Boss’ new XS-1 Poly Shifter literally stretches the instrument’s vocal range. With the ability to shift input by +/-3 octaves or semitones, it can turn your guitar into a bass, a synth, or a baritone, or function as a capo. It also seamlessly generates harmonies for single note leads and keeps up with quick picking without any apparent latency. Furthermore, the pedal is capable of stranger fare that stokes many out-of-the-box ideas. But if you’re a guitarist that plays more than one role in your band—or musical life in general—the XS-1 can be a utilitarian multitool, too. It’s a pedal that can live many lives.
- YouTube
The XS-1, which was released alongside its bigger, more intricate sibling, the XS-100, is an accessible route to exploring pitch shifting’s potential. Housed in a standard Boss enclosure, it doesn’t consume a lot of floor space like the XS-100 or DigiTech’s Whammy. And while it achieves this spatial economy in part by forgoing a built-in expression pedal (which could be a deal breaker for some potential customers) it’s still capable of +/- seven semitones and a +/- three-octave range that can be utilized in momentary or latching applications.
Slipping, Sliding, and Twitching
Though digital pitch shifters have always been capable of amazing things, early ones sounded very inorganic at times. High-octave sounds in particular could come across as artificial, like the yip of a robot chihuahua plagued by metal fleas. Some very creative players use these colors—as well as the most sonorous pitch shift tones—to great effect (Nels Cline and Johnny Greenwood’s alien tonalities come to mind). In other settings, though, these older pitch devices can be downright cringey.
“The pedal clearly represents several leaps forward from first-generation pitch shifters.”
The XS-1 belies digitalness in some octave-up situations. But the pedal clearly represents several leaps forward from first-generation pitch shifters. Tracking is excellent and shines in string bending situations. Semitone shifts can provide focused harmony or provocative dissonance depending on the wet/dry mix and which semitones clash or sing against the dry signal. At many settings the XS-1 feels alive and organic, too, with legato lines taking on many of the touch characteristics of a violin-family instrument. You get far less of a note-to-note “hiccup,” and glissandos take on a beautifully fluid feel—with or without a slide—letting the XS-1 deliver convincing pedal- and lap-steel-style textures when you add a single octave up. (Such applications sound especially convincing when you kick back on guitar tone and restrict your fretwork to the 3rd through 5th strings, which keeps digital artifacts at bay.)
Mixmaster Required
The most crucial XS-1 control is the mix. For the most convincing bass, baritone, and 12-string tones, you’ll want a fully wet signal. But composite sounds can be awesome, too. You can use the control’s excellent sensitivity and range to highlight or fine tune the prominence of a consonant harmony. But it’s sensitive enough to make blends with dissonant harmonies sound a lot more intentional and integrated. And many of these eerie, wonky, off-balance textures are extra effective when introduced in quick bursts via the momentary switch. (That switch can also deliver great flashes of drama with more consonant harmonies—like dropping in a 3rd or 5th above a resolving chord in a verse.)
You can get creative in other ways using dissonant blends. Droney open tunings can yield fields of overtones that sound extra fascinating with delay, reverb, or 12-string guitar… or all of them! Dialing in blends that really work takes some trial and error, and you’ll definitely hit a few awkward moments if you’re navigating by instinct alone. But those same experiments often uncover real gems—especially in the pitch-down modes, which tend to produce more mysteriously atmospheric textures than their pitch-up counterparts.
The Verdict
Boss’ most straightforward pitch shifter covers a lot of ground. If you play in a duo, trio, or small band, it can expand that collective’s stylistic and harmonic range. It’s small, at least relative to treadle-equipped pitch shifters, so if you’re not a pitch shift power user, you don’t sacrifice a lot of room for an effect you might only employ occasionally, and you can still use the expression pedal jack to hook up a pedal for dynamic pitch control. The $199 price puts it in line with competitors of similar size and feature sets, but the XS-1 is a great value compared to more elaborate, treadle-equipped pitch shifters. If you’re taking your first forays into pitch shifting, or know that you need only the most straightforward functions here, it will ably return the investment. And along the way, it might even unlock a whole cache of unexpected tonal discoveries.
