Phasor II

Mu-Tron Phasor II

Mu-tron Phasor II is a new, advanced phase-shifting device designed to give the musician true state-of-the-art performance in a rugged, compact package at a very affordable price. The original Mu-tron Phasor has been used with great success by professionals all over the world. As a second generation model, Mu-tron Phasor II offers significantly improved performance – made possible by adapting the advanced electronic technology developed for the revolutionary Mu-tron Bi-Phase. Six phase-shift stages provide a maximum of 1080 degrees of phase-shift for a deep, satisfying phasing effect. Mu-tron Phasor II features the exclusive feedback circuitry first introduced on the Mu-tron Bi-Phase to produce a distinctive, pronounced sweeping effect – even at the slowest phasing rate. The new circuitry has extremely low noise and unequaled signal-handling capability for freedom from distortion. This makes Mu-tron Phasor II ideal for use after a pre-amplifier or with high-output electric keyboards, and also for critical use with electric guitars or other instruments in the studio or on stage. Three continuously variable controls are provided for Rate, Depth and Feedback. These give the musician complete and effective control of his sound over a very wide range of possible effects. Mu-tron Phasor II is AC powered for quiet, reliable operation without the annoyance of frequent battery changes. First quality components are used exclusively. The housing is made of heavy gauge steel and thick, rugged epoxy-finished aluminum that will stand up to hard use on the road.”

– From original Musitronics Phasor II ad circa 1970s


  • Rate controls the speed/rate of the LFO wave that controls the effect
  • Depth controls the depth/amplitude of the modulation (the size of the range in which the effect sweeps).
  • Feedback sets the amount of effected signal fed back into the effect (for a stronger effect)


  • Input Impedance: 390K ohms, unbalanced
  • Output Impedance: 600 ohms, unbalanced
  • Gain: Unity (Less than 1db insertion loss)
  • Frequency Response: (Bypass) 20Hz – 20KHz ± 2db
  • Signal Handling Capability:
    • Minimum Feedback: 4V RMS, 11.2V Peak-to-Peak
    • Maximum Feedback: 2V RMS, 5.6V Peak-to-Peak
  • Signal-to-Noise Ratio: Better than 86 db below 2V input
  • Phasing Rate: 1Hz to 18Hz
  • AC Power Requirements: 115V AC, 50-60Hz, 5 watts (230V AC, 50-60Hz available on special order)
  • Weight: 3½ pounds
  • Dimensions: 8¾” l.  X  5″ w.  X 3⅛” h.


gearmanndude’s Phasor II Demo

Original Owner’s Manual: