Discover the rich, analog character of the Pigtronix RESOTRON, a dynamic envelope-controlled filter that brings vintage synth-style filtering to your pedalboard. Inspired by the SSM2040 filter chip found in early Sequential Circuits synths, the RESOTRON delivers responsive low-pass, band-pass, and high-pass filter modes with adjustable resonance and an ultra-expressive envelope follower. This used unit is in Good condition with minor cosmetic wear but functions perfectly. It features analog circuitry, true bypass switching, and top-mounted jacks for easy pedalboard integration. Powered via standard 9V DC (center-negative), it's perfect for guitar, bass, or synth players looking for soulful auto-wah tones, squelchy sweeps, and resonant filter effects. Add a powerful sonic tool to your rig with this rare and highly musical pedal.