Infinitphase MkII

Infinitphase MKII overview

The now-classic infinitphase MkII is available once again. Imagine the marriage of a phase shifter and analog sequencer, and you'll be imagining something like the infinitphase. However, the infinitphase gets a little twisted and goes far beyond any existing phaser or sequenced device to offer:

• extended LFO rate variable from .1Hz to 10Hz
• triangle / sawtooth / square / pulse / blended LFO shapes OR step-phased tones OR a blend of both for phased / filter sounds that are out of this world
• slew-rate limiting for step-phase control section producing classic sample-and-hold effects or meandering phase tones
• positive AND negative resonance adjustable via a single control
• a blend of wet and dry signals for subtle phase or outrageous vibrato
• AC-powered, internally-regulated +/-15VDC power supply providing a huge amount of headroom for any signal source (guitars / synths / drum machines / etc)

The dimensions of the infinitphase Mk II are: 20.5cm W x 15.cm D x 6cm H (to top of knobs): 8" W x 5.9" D x2.4" H

The infinitphase's audio section is based on a Mutron Biphase channel (extended to a maximum of 8 phase stages) and, along with the simple yet flexible control section, allows users to emulate traditional phase tones or explore never-before-heard filtering / phase / vibrato / S&H effects.

A brief overview of the 'standard' infinitphase Mk II's controls (more detailed information can be found in the user manual):

• rate - controls the rate at which the LFO cycles
• symmetry - controls the rise/fall or mark:space ratio of the LFO
• shape - pans between triangle and square LFO waveshape
• depth - adjusts the LFO depth
• range - determines how many phase depth controls are cycled through by the LFO
• smooth - adjustable sle-rate limiting of the changes between phase depth control settings
• cvmix - determine whether the phasing is controlled by the LFO, the phase depth controls, or a blend of both
• blend - controls the blend of clean / effected audio
• resonance - selects whether the phased signal is mixed in-phase or out-of-phase with the clean signal
• phase depth controls - 9 controls that are stepped through by the internal LFO, and which determine the phase depth when selected

Custom modifications

A number of modifications to the base model infinitphase are available as optional extras.  

[Audio mod] 4/8 phase stage toggle switch

A toggle switch selecting between 4 and 8 phase stages is added for this mod, allow a 'classic' phase tone to be achieved.

[Audio mod] stereo output

Additional circuitry + another output is added to provide a full stereo-imaged phase sound. Note that this modification involves making the pedal buffered-bypass; the pedal will only pass sound if the power supply is plugged in.

[CV mod] LFO speed toggle switch (for pseudo-ring mod sounds)

A toggle switch is added close to the stock rate control for selecting between two LFO speed ranges - normal and high. At high LFO rates the result is very similar to a true ring modulator, only the resultant tones are far more tweakable via the multitude of controls on the infinitphase affecting both the character of the modulating voltage control signal and also the characteristics of the processed audio.

[CV mod] control jacks for LFO speed, LFO depth and phase-step range

One, two or three 1/4" jacks can be added for external control of LFO speed, LFO depth and phase-step range control via either a volume pedal orexpression pedal.

[CV mod] LFO height control

This mod consists of an extra control added to the front of the infinitphase, making it possible to adjust the centre frequency around which phasing occurs. This allows selection of phasing over lower frequencies only or higher frequencies only, or anywhere inbetween. On non-modded infinitphases the centre frequency is adjusted during the final stage of testing for optimum sweep range in conjunction with the depth control.

[CV mod] S&H LFO (with engage switch and rate control)

A toggle switch is added to allow selection of the internal step phase voltages LFO, or the control voltages produced by a classic S&H circuit; a 'rate' control is also added to allow control over the rate of change of the random effect. This mod produces a close approximation of 'classic' sample-and-hold-type sounds, while still allowing the user to retain full control over the nature of the phase/filtered tones produced. When blended with the internal triangle or square waveforms via the CV mix control, many new and wonderful sounds are possible!

[CV mod] CV out socket

One or more CV-out sockets can be added to allow controlling of external devices that accept CV in. The 'raw' CV out voltage is in the 0-11V range, however this can be scaled up or down to match any CV input requirements.

[CV mod] CV in socket

A single CV-in socket, with toggle switch to select between internal or external control, can be added to allow the infinitphase's phasing section to be driven via external CV, or via an expression pedal (eg Boss EV-5). CV range must be in range 0-5V.

[CV mod] Expression pedal sweep

A 1/4" jack is added to which an expression pedal (Boss EV5 or equivalent) can be connected, allowing foot control over the sweep of the phase. A toggle switch is also added to allow selection of the internal tri/sqr LFO, or the expression pedal sweep; or you can choose to have the sweep pedal work all the time it is inserted into the control jack.

Notes on limits with respect to voltage control and mods

A standard model infinitphase comes with two sources of voltage control - the step sequencer and the internal LFO - with a blend control to adjust the amount each voltage control source affects phasing. With the exception of the CV in mod, which replaces entirely the internal voltage control system when activated, there is a limit of two additional CV mods. For example, a 'fully loaded' infinitphase might include both the S&H mod and the expression pedal mod. The voltage control options would then be: 1) one of the internal step sequencer OR the S&G mod AND 2) one of the internal LFO OR the expression pedal mod< Or, to put it another one, any one of two voltage control sources in each of the two voltage control groups above can be selected as active as one time.