The Keeley Neutrino gives you all the classic, funk, auto-wah sounds and that Jerry-In-A-Box sound. We have used the classic opto-coupler design for a rich and warm depth to the effect. Envelope filter sound is an effect triggered by your pick attack or strength. The harder you pick, the harder it “wahs”! Sounds bubble up from a deep rounded warmth to a shinning brilliance. Solo notes are individually expressive based on how hard you play.