Guitar Aficionado

Keeley Neutrino Envelope Filter Now Shipping

The pedal's neo-vintage circuit delivers auto-wah and envelope follower effects.

By Christopher Scapelliti

Keeley Electronics is now shipping its Neutrino Envelope Filter effect pedal.

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The Neutrino is a modern compact circuit of an opto-coupler-based design. The pedal is entirely hand-built in the U.S. and offers a wealth of studio-quality musical tones, from classic wah sounds to vocal and vowel sounds all based on pick dynamics or input level.

The Neutrino has controls for input gain, resonance peak, filter selector, tone range, and drive direction, all of which make it easy for players to dial in all of the classic auto wah tones. The pedal’s side-mounted recessed drive switch and internal output volume were designed to keep the look ergonomically clean.

"Our design team focused on building a tunable dual opto-coupler design that could be aligned for unit-to-unit perfection,” says Robert Keeley, Keeley Electronics’ founder and chief engineer. “Opto-coupler-based envelopes can be expensive, bulky, and can have variances in sound quality, so our goal was clear: create a best-in-class product that combines compact versatility, repeatable musical tone, and low noise in a compact effect.”

Like all of Keeley Electronics’ designs, the Neutrino Envelope Filter is hand-built in the U.S. using the finest components and construction techniques. It is housed in a beautifully powder-coated and rugged enclosure, includes true bypass switching, and features a two-year limited lifetime warranty with Keeley customer support.

The Neutrino has a street price of $229. Visit for more information about the full lineup of Keeley Electronics effects.