Electro-Harmonix releases Pico Swello attack envelope pedal at $149.50

September 17, 2025 · 3 sources

Electro-Harmonix introduced the Pico Swello Attack Envelope pedal, a polyphonic auto-swell effect drawn from the POG2, with a US list price of $149.50 and availability from mid-September¹. Guitar Pedal X reported the pedal on September 17, 2025, at $150 on the EHX Webstore².

The core effect is a polyphonic attack filter that applies individual volume swells to each note played, including notes within chords and sustained arpeggios, paired with an adjustable low-pass filter¹. The pedal is housed in EHX's Pico-sized chassis with a four-knob, one-button layout¹. Gearnews describes it as a polyphonic envelope follower, an optional low-pass filter and a compact design, with mono input and output and a single footswitch³.

Guitar Pedal X describes the filter button as three-position, with green disabled, amber low resonance and red high resonance². Gearnews describes two filter types selectable with the button³. The pedal ships with a standard EHX 9 Volt power supply¹.

Guitar Pedal X reported the price as $150 on the EHX Webstore and said Andertons in the UK did not have it in stock, with no reference to incoming stock². Premier Guitar gave the US list price as $149.50¹.

Guitar Pedal X's Stefan Karlsson wrote that the violin and cello-like tones in the demo sounded superb and called the pedal "a winner for me for sure"².