Vintage Musitronics Mu-Tron III Envelope Filter & PS-1 Power Supply

The Holy Grail of Vintage Auto-Wah, Upgraded for Pro Reliability Step into the exact tone that defined 1970s funk, R&B, and jam band history. This is an original, 1970s Musitronics Mu-Tron III, the world's very first envelope filter. Designed by Mike Beigel, this pedal provided the signature squelch for Bootsy Collins, the dynamic quack for Jerry Garcia's legendary solos, and the iconic clavinet sound on Stevie Wonder's "Higher Ground." What sets this specific unit apart is its provenance and reliability. It includes the highly sought-after original Musitronics PS-1 bipolar power supply, which has been professionally installed by the legendary Dave Friedman of Friedman Amplification. This expert installation ensures that this vintage masterpiece operates flawlessly and safely, whether it is sitting in a studio rack or touring on a professional pedalboard. Key Features & Historical Details Friedman Amplification Installation: The original PS-1 power supply (+9V, 0, -9V) was professionally installed by Dave Friedman, guaranteeing top-tier electrical integrity and absolute peace of mind for the next owner. Original Opto-Isolator Magic: The heart of this pedal remains completely intact. Internal photos reveal the original photo-resistor (vactrol) technology that gives the Mu-Tron III its unmatched vocal, organic sweep. Unmodified Vintage Circuitry: The "musitronics 0601" circuit board retains its vintage integrity, featuring period-correct MIAL ceramic capacitors and original traces. Complete Control: Features original rotary knobs for Mode (Low Pass, Band Pass, High Pass), Peak, and Gain, alongside heavy-duty rocker switches for Range and Drive direction. Bipolar Power Ready: Say goodbye to burning through dual 9V batteries. The installed PS-1 provides the exact bipolar voltage this demanding circuit requires for maximum headroom and dynamic response. Condition This pedal is in excellent vintage condition. The heavy-duty metal enclosure shows normal, authentic wear and minor internal surface oxidation typical of genuine 1970s Musitronics gear, which does not affect performance.