Electro-Harmonix Pico Swello Attack Envelope Effect Pedal

The Electro-Harmonix Pico Swello is a groundbreaking compact effects pedal designed to deliver rich, polyphonic volume swells and reverse effects with unmatched precision. Drawing inspiration from the renowned POG2 Polyphonic Octave Generator, the Swello automatically applies a smooth, natural volume envelope to each note—no need to tweak sensitivity or alter your playing technique. Perfect for guitarists seeking ambient textures, cinematic swells, or dynamic tone shaping, this pedal redefines expressive performance.

Beyond volume shaping, the Swello features a responsive low-pass filter with two adjustable resonance modes, allowing players to sculpt tone depth and harmonic complexity. The filter’s cutoff frequency can be modulated by the attack envelope, unlocking lush, polyphonic envelope filter effects that respond musically to every note. With intuitive controls including VOL, ATTACK, FREQ, and MOD, the Swello offers total control over output, envelope timing, and filter sweep direction for both upward and downward modulation.

Built with a buffered analog bypass, the Swello ensures clean signal integrity when disengaged and pristine tonal clarity when active. Its compact chassis, 9 V DC power operation, and rugged construction make it equally suited for studio production and live performances. Whether you’re exploring ethereal ambient layers, reverse-style swells, or expressive filter movements, the Electro-Harmonix Swello delivers professional-grade tone shaping in a versatile, pedalboard-friendly design.