Electro-Harmonix Pico Intelligent Harmony Machine

The Electro-Harmonix Pico Intelligent Harmony Machine is a digital harmonizer pedal released in 2026. You set a key and an interval, play single-note lines, and the pedal generates a diatonic harmony line that follows you, so a single guitar can produce two-part harmony, or three parts in Dual Mode. Electro-Harmonix describes it as creating "2 or 3-part harmony in any key with silky smooth operation and lightning fast-tracking to keep up with any speedy lick"¹.

It packs the diatonic functionality of the full-size Electro-Harmonix Intelligent Harmony Machine into an ultra-compact Pico enclosure, and Pedal of the Day called it EHX's most compact harmonizer ever². It sits in the octave and pitch family alongside pedals like the Pico POG and Pico Pitch Fork, but where those shift pitch by a fixed interval, the Pico IHM shifts by a musical interval that changes with the notes you play, so the harmony stays in key.

What it does: diatonic harmony from single notes

A fixed pitch shifter moves every note by the same distance, which sounds wrong as soon as you change chords. The Pico IHM instead generates diatonic harmonies in a set key based on the single notes you play, so the harmony note is always a scale tone in that key². This is the same Intelligent Harmony Mode approach as the original Intelligent Harmony Machine, which generates single-note diatonic harmonies in a set key with two- and three-part harmonies⁵.

The trade-off is that the pedal is designed to work with single notes only. Playing multiple notes or chords may not work well, as Pedal of the Day noted². Guitar World's Trevor Curwen found one exception: the pedal "will go polyphonic if you choose an octave interval"⁴.

Ten intervals, 12 keys and Dual Mode

The Key knob selects from 12 keys, and the Interval knob selects from 10 harmony intervals⁴²:

The ten settings cover the canonical harmonic moves: thirds, fifths, sixths and octaves, according to Delicious Audio⁶. For the single harmonies you can choose 6th, 4th and 3rd down, plus 3rd, 4th, 5th, 6th and 7th up⁴.

The # button switches between a natural and a sharp key: green for natural, red for sharp. Press and hold it for one second to enable Dual Mode, in which the pedal synthesizes two different intervals simultaneously, adding a second voice for 3-part harmonies¹. Delicious Audio called Dual Mode the pedal's "true glory: three-part harmonies"⁶.

One thing to know about keys: all of the keys on the dial are major. To play in a minor key you need to do some on-the-fly transposition in your head, or use the lookup table in the manual, as Guitar.com's Cillian Breathnach explained³.

Controls and bypass

Bypass is buffered, not true bypass⁴. Connections are a standard input and a standard output, mono only¹⁴. Guitar.com's reviewer found the build solid: "it's a fairly heavy little thing, with sturdy knobs and jacks, particular the audio jacks, which are the type that lock" onto patch cables³.

Power

The pedal runs on the included 9.6VDC-200mA power adapter, with a current draw of 100mA at 9.0VDC¹. Premier Guitar confirmed it ships with the standard EHX 9V power supply⁷. Unlike the full-size Intelligent Harmony Machine, which can also run on a 9 Volt battery, the Pico version's spec lists the adapter only⁵.

A compact version of the Intelligent Harmony Machine

The Pico IHM keeps the main parts of the Intelligent Harmony Machine in a smaller form with fewer controls, priced at $149 as its US street price¹. Guitar.com noted the Intelligent Harmony Machine line has now been folded into EHX's NYC DSP range³.

What reviewers said

Guitar.com's Cillian Breathnach found the generated harmony "sounds ok, sometimes great, particularly in the octave and fifth modes," and concluded³:

His verdict, in other words, was that the pedal is good enough for live usage but not for recording sound quality³.

Two octave tricks stand out from Guitar World's review: with the octave down and the Mix knob up full, "you'll be able to play basslines if needed," and with the upper octave and the Mix set appropriately low you can dial in an approximation of 12-string jangle⁴.

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