Bi-Phase

Mu-Tron Bi-Phase

“The World’s First Dual Phasor

The Mu-Tron Bi-Phase consists of two independent 6-stage phasor circuits, two sweep generators (oscillators), and a number of unique additional controls to allow maximum flexibility in generating a variety of phasing effects. The Mu-Tron Bi-Phase also offers several convenience features including LED indicators on each phasor, mike stand socket on bottom of housing for above-the-floor mounting, and AC cord storage on back panel. The unit is furnished with a dual foot switch and has an optical photoelectric foot pedal and provision for synthesizer interface for external control of sweep. And, like all Mu-Tron products, the Mu-Tron Bi-Phase and its accessories are solidly constructed to withstand the most severe professional use.”– From original Musitronics Bi-Phase ad circa 1970s

Controls:

Sweep Generator 1

  • Rate controls the speed/rate of the LFO wave that controls the effect
  • Man/Ped switches the rate of the LFO between the setting of the Rate knob and the pedal.
  • Shape switches the LFO between a square and a sine wave

Sweep Generator 2

  • Rate controls the speed/rate of the LFO wave that controls the effect
  • Shape switches the LFO between a square and a sine wave

Phasor A

  • 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)
  • Sweep (Ped/Gen 1) switches the sweep control of the phasor between pedal control and LFO control by Sweep Generator 1

Phasor B

  • 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)
  • Sweep Sync (Norm/Rev)switches between normal sweep and reverse sweep (if you use the same sweep source as phasor A, phasor B will move in the opposite direction)
  • Sweep (Gen 1/Gen 2/Ped) switches the sweep control of the phasor between pedal control, LFO control by Sweep Generator 1 and LFO control by Sweep Generator 2
  • Phasor B Input selects a source for Phasor B: input A (same input as Phasor A), output A (Phasor B gets the output of Phasor A as input), input B (separate input for Phasor B)

Specifications:

  • Input Impedance: 300k ohms minimum, unbalanced
  • Output Impedance: 600 ohms, unbalanced
  • Insertion Loss: Less than 1db
  • Frequency Response (Bypass): 20Hz – 20kHz ± 2db
  • Signal Handling Capability:
    • Each Phasor, no feedback, 4V RMS minimum.
    • Both Phasors (in series), 50% feedback, 2V RMS minimum.
    • Both Phasors (in series), 100% feedback, 1V RMS minimum
  • Phasing Rate: Sweep Generators .1Hz-18Hz
  • AC Power Requirements: 115V AC, 60Hz, 15 watts
  • Dimensions: 13¾” w.  X  10¾” d.  X  4¼” h.
  • Weight (less footswitch and foot pedal): 7¾ pounds

Demo:

hiwattbob’s Bi-Phase Demo

Original Owner’s Manual: