Prophecysound Systems Pi-Phase mk2 dual phase shifter


The Pi-Phase mk2 is a very accurate reproduction of the original Mu-Tron Bi-Phase dual phase-shifter, but in a much more compact format much more suited to pedal-boards / live use.  The original Mutron pedal is one of my all-time favourite effects and I have been waiting for years for Mike to finalize the Pi Phase. If you haven't tried one out, trust me it will blow your mind.

Prophecysound Pi-Phase mk2 overview

The Mu-Tron Bi-Phase is a dual phase-shifter invented and marketed by Musictronics USA in the 1970's. It has become well-known and well-loved for it's 'classic' warm and deep sound, as well as the flexibility of it's control and audio-processing capabilities. The Prophecysound Pi-Phase mk2 seeks to accurately reproduce the sound and control layout of the original unit. Design goals for this reproduction of the Bi-Phase were:

  1. to match, as closely as possible, the sound of the original
  2. to maintain the same or a very similar control layout
  3. to package the pedal in a size and format that would allow it to be used live
  4. to dispense with the need for a special controller pedal for switching channels on/off, or for controlling pedal sweep

The Pi-Phase mk2 is all-analog and parts-accurate to the original, as much as is possible. To our ears, and the ears of many previous customers, the Pi-Phase mk2 sounds like the real-deal. How much like it? Original Bi-Phases are pretty old, and some units suffer from parts drift, lack of maintenance, and lack of calibration; each 'well-gigged' Bi-Phase can easily sound different to the next. With the Pi-Phase mk2 we give you 'factory fresh' dual-phaser experience.

The control layout was condensed to fit the targeted pedal format, while still providing a clear and understandable way of operating the unit. The original architecture of the dual LFOs / dual phase shifters has accurately been retained. As per the original, a manual isn't really even needed to explain how the unit works, or what the possibilities are. The resultant format - a pedal 50mm (~2") high, 188mm (7.4") wide and 122mm (4.8") deep - can readily be accommodated on most pedal-boards. The Pi-Phase mk2 is powder-coated and the labels are made out of industrial-strength polycarbonate for looks that will resist the worst live gigs have to offer.

No special extra foot-switch is necessary to operate the Pi-Phase mk2; true-bypass foot-switching for each individual phase channel is built into the pedal. An expression pedal may be connected to the CV PEDAL socket at the rear of the Pi-Phase mk2; the pot in the expression pedal should be connected across the sleeve and ring terminals of a stereo cable, with the wiper connected to the tip. We recommend an expression pedal that incorporates a 10k linear pot (e.g. Boss EV-5, EV-7) for optimal performance. Alternatively, you can connect an external CV signal in the range of 0-5V for controlling the Pi-Phase mk2 from a modular synth or modulation source. Either method - expression pedal or CV - allows controlling of LFO speeds and / or manual sweep of the phase sections.

Each pedal comes with reproductions of the original unit's program cards, including a new preset of Prophecysound design, and some blank program cards to record your own settings. A printed manual, with quick-start and detailed information on the pedal, is also supplied. A PDF of this manual is available for download at the bottom of this page.

Locally made for the highest quality

This pedal is manufactured and assembled in Adelaide, South Australia. Prophecysound believe in working with people we can meet and discuss their requirements with face-to-face, and in utilising local companies to stimulate the economy. Most importantly, their local manufacturers have many years of experience, and they trust them to help produce products that are second-to-none in terms of quality and reliability.

Please note: Prophecysound claims no association with Mu-Tron / Musitronics / Mike Beigel or Aaron Newman. The Pi-Phase mk2 is a, if you like, fan-based tribute to the original unit, and addresses a long-standing technical challenge and curiosity.

**Please note - It is important that this version of the Pi-Phase mkII only be powered with a 9vDC or 12vDC Regulated power supply, centre negative.

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We are very picky about the product lines we carry here.  They must have great tone, stellar reliability and the right vibe.  Thus far, We are very impressed by all of the manufacturers we deal with .  In addition, the manufacturers we carry all have one big thing in common:  They are all Super-creative People that are fun and easy to deal with!