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Prism III Modulation-Filter-Pad

The Prism III is a unique sound texture generator. The pedal's 22 complex algorithms combine additive synthesis, reverb and various types of modulation (frequency, amplitude, time). It's hard to pinpoint a single role for this compact stereo device, so the name highlights its three key elements: modulation, filtering, and pad creation.

The Prism III can be easily integrated into any setup (even the most esoteric one). The pedal's interface saves settings automatically, and the parameters can be controlled externally via MIDI or CV.

Key Features

  • A complex, one-of-a-kind effect pedal: each algorithm can feature up to six resonant filters, three pitch shifting sections, two delay time modulation sections, amplitude modulation, reverb, sample rate reduction, and two non-linear distortion sections.
  • 22 unique algorithms ranging from traditional modulation effects to sound generation based on the input signal.
  • 33 programs split into 3 banks + Quick Access functionality.
  • A User Defined bank where 11 favorite programs can be saved.
  • An interface which automatically saves all the algorithm's parameters into the program.
  • Tap tempo with note subdivisions and rate modifier (which can make the modulation rate up to 32 times faster or slower).
  • Detune Mode: gradual pitch shifting of the transposed signal.
  • Dual mono signal processing and a fully featured stereo signal path with mono expansion capabilities.
  • A universal external control input which accepts MIDI, passive controllers, expression pedals and analog triggers.
  • Analog wet/dry cross mix with signal boosting capabilities.
  • Fully analog dry signal path.
  • Switchable reverb tails in bypass.
  • Firmware updates and configuration via USB Type C.
  • Lightweight and compact aluminum enclosure featuring top-mounted jacks for improved connectivity and easier pedalboard management.
  • Universal power intake in the 9-12V range; low current draw by digital device standards (160-200mA).



LEFT IN is a monophonic signal input. In a mono signal chain, use this input exclusively.


The Prism III has multi-function controls: each knob and switch can have several purposes. The primary functions are printed in bold. Secondary functions which can be accessed by holding down the TAP / ALT footswitch are printed on the pedal with a border (and printed here in italics). The ones which can be accessed by holding down the ON / DETUNE footswitch are underlined. In this text, each function is marked by the same principle.

Tweaking a secondary control function has no effect on the primary control function value, and vice versa. The primary and secondary functions are independent from each other, but only the latest one you've tweaked will have a physical representation (because they are controlled by the same knob or switch).
The BANK switch selects among the effects banks:
  • UP: UD (User Defined) — user-selected algorithms.
  • CENTER: FX (Effects) — modulation effects.
  • DOWN: PM (Prism) — complex effects.
Please see the Program Management section for details.
While holding down the TAP / ALT footswitch:
The COPY SETTINGS knob copies the current settings for all interface elements to another slot as soon as the ALT footswitch is released.
Please see the Program Management section for details.
When you press and hold the ALT footswitch, the LED above it glows blue. This indicates that you're accessing secondary functions of interface elements.
While holding down the DETUNE(ON) footswitch:
The STEREO knob shifts LFO phase in the right channel. This allows you to control signal panning. Different programs have different depth ranges.
Press and hold the DETUNE footswitch to go into gradual detune mode. The parameters accessed by holding down the DETUNE footswitch don't have an immediate effect on the sound; instead, the effect becomes noticeable over time.

Bypass and Indication

The dry signal doesn't go through any AD/DA conversion, so it doesn't get delayed or affected in any other way. The Prism III uses active bypass and VCA-based dry/wet mixing; this eliminates extra noises when turning the pedal on and also allows you to select between two signal chain options (as described below).
Press and hold the ON footswitch, then move the BEAT switch to one of the following positions:
  • UP: Tails mode. When you press the ON footswitch to turn off the pedal, reverb tails will keep playing but no signal will be fed into the processing chain anymore.
  • DOWN: No tails mode. You can only hear the effect when the pedal is on. As soon as you press the ON footswitch to turn the pedal off, reverb tails will be cut off instantly.
The Kill Dry mode is accessed via the X-MIX knob. When using the Prism III in a setup with external mix control, it's recommended to set the X-MIX knob fully CW.

The bypass mode is displayed as soon as you've selected it (and also when you connect the pedal to a PSU). The LED over the ON / DETUNE footswitch flashes 5 times in one of the following colors:
  • White: Tails mode.
  • Red: No tails mode.
The ON / DETUNE LED has five functions:
  1. On/off indication. If the pedal is bypassed (disengaged from the signal chain), the LED doesn't light up.
  2. Active bank indication. Upon power-up, the LED displays the selected bank: Blue (PM), Red (FX) or Magenta (UD).
  3. Detune Mode status indication. When the DETUNE footswitch is held down, the LED flashes in various colors.
  4. Quick Access status indication. When the Quick Access program is recalled, the LED glows green. If the pedal is bypassed, the LED flashes briefly to indicate that the Quick Access program will be active when the pedal is turned on.
  5. Bypass mode indication upon selection or power-up.

Connection Options

LEFT IN is the main mono input. If you are using the pedal with a mono signal source, use that input exclusively.

Connect the signal source to the LEFT IN input, then connect the LEFT OUT output to the signal receiver.

Processing Chain

The signal processing chain in the Prism III is arranged in the following order:
  1. Input signal mixer with 3 pitch shifter channels (octave down, 5th up, octave up). The transposed signal has its own LFO for detuning.
  2. Three resonant multimode filters (LPF, HPF, BPF, All-Pass — each with its own mixer and tremolo mode), arranged in series.
  3. First delay modulation section.
  4. First non-linear distortion mixing section.
  5. Reverb section.
  6. Sample rate reduction (SRR) section which adds a Lo-Fi character to the sound.
  7. Three more resonant multimode filters (LPF, HPF, BPF, All-Pass — each with its own mixer and tremolo mode), arranged in series.
  8. Second non-linear distortion mixing section.
  9. Second delay modulation section.
  10. Shelving high-pass filter for the output signal.
  11. Output mixer which adds the processed signal to the dry signal.
To sum up, the pedal has 3 pitch shifter sections, 6 filters/tremolo effects, 2 non-linear distortion stages, 2 delay modulation sections, a sample rate reduction section, a reverb section, and an output mixer.

The pedal's 22 algorithms are based on these processing elements, although not all of the elements are necessarily used in each algorithm.

Main LFO
Parameter modulation is one of the key elements of the Prism III. Modulation depth is set by the DEPTH knob, while the rate can be set by the RATE knob or the TAP footswitch. The Prism III has 5 LFOs which have different settings for different algorithms. Those allow you to create basic modulation effects, expand a mono signal to stereo, pan the signal across the stereo field, or apply phase distortion.

Modulation Rate Setup

Use the RATE knob, TAP footswitch and BEAT switch to set the modulation rate. The resulting rate is equal to RATE * BEAT (or TAP * BEAT): the RATE knob and TAP switch set the base rate in quarter notes, which then gets altered by the BEAT switch. The BEAT switch allows you to turn quarter notes (*1) into dotted 8ths (*0.75) or quarter triplets (*0.66666). You can also set your own tap division values through the config file. The TAP LED displays the set LFO rate.

In most algorithms, the range of the RATE knob is 60 to 0.125s (0,01666(6) – 8Hz); the set rate can be altered via the BEAT switch.

The TAP footswitch and the RATE knob have the same effect on modulation rate, which is determined by the control that has been used last.

The TAP footswitch sets the modulation rate after two consecutive taps. Additionally, there's an extra mod rate setting as long as the rate is set via the TAP footswitch or external control. The SCALE knob can divide or multiply the rate by fixed values between 2x and 32x. Turn the knob CCW to slow the LFO rate down (divide) or CW to speed it up (multiply).

The pedal allows external control over modulation rate via MIDI or analog triggers. Please see the External Parameter Control section for details.


The STEREO knob affects LFO phase in the right channel. As a secondary function, it is accessed by holding down the ON/DETUNE footswitch.
Set the knob fully CCW to have the phases perfectly in sync. Set it to 12 o'clock for a 180-degree phase offset. In the fully CW position, the phase is offset by 360 degrees. This allows you to control signal panning across the stereo field. Keep in mind that phase offset values can be different from 0 in various elements of the signal chain; this means that the STEREO knob will either "expand" the stereo stage or move the elements to different positions in the stereo field, depending on the program.

Program Management

The terms "algorithm" and "program" are used in the Prism III's interface.
  • Algorithm refers to one of the 22 signal processing algorithms assigned to memory slots 1-22 (PC 0-21). Algorithms have fixed positions and reside in the PM and FX banks. Their positions reflect the values of the PROGRAM knob, as defined in this manual (please see the Algorithms section for details).
  • Program (patch, preset) refers to a full set of parameter values for a particular algorithm along with its number. Programs are stored in the pedal's memory. The first 22 programs are linked to algorithms with a matching position on the PROGRAM knob. A program can also be freely saved into the UD bank along with a relevant algorithm; in this case, it will be assigned to memory slot 23-33 (PC 22-32).
Upon power-up, the pedal reads all program settings from memory, and all saved settings are restored. This way, the Prism III can be seen as a collection of presets accessed via the PROGRAM knob. The loaded program settings might not be reflected through the physical interface, but changing any parameter will automatically prompt the interface to update and save that value.

The Prism III allows you to change programs via the CTRL input. By default, the CTRL input is set to receive MIDI (Channel 1). You can change the MIDI channel and other parameters via the Setup Mode (without having to connect the pedal to a computer).


The Prism III includes 22 processing algorithms. The best programs from the Prism II have been updated to match the improved processor capabilities. Parameter ranges for filters and processing effects have been expanded. Thus, the new versions aren't carbon copies of their Prism II counterparts: they have undergone multiple notable improvements.

The built-in algorithms are split into 2 banks:
  • PM: unique complex effects (a.k.a. the Prism classics).
  • FX: modulation effects with extra capabilities.
The UD bank allows the user to place algorithms in any order.

NB: You can replace or reconfigure any of the 22 default algorithms. An alternative algorithm pack will be added later to the Prism III support page. We're also working on a software editor for algorithms and presets.


The Prism III has 33 memory slots for programs. The programs are split into 3 banks of 11 slots each. To select the bank, set the BANK switch to the desired position:
  • UP: UD (User Defined). The LED above the ON footswitch lights up in magenta. This is essentially a "favorites" bank which contains programs and algorithms saved by the user in arbitrary order. The first program of the UD bank is also the Quick Access program.
  • CENTER: FX (Effects). The LED above the ON footswitch lights up in red. This bank contains modulation effects. The positions of this bank's algorithms cannot be changed.
  • DOWN: PM (Prism). The LED above the ON footswitch lights up in blue. This bank contains complex effects. The positions of this bank's algorithms cannot be changed.
Turn the PROGRAM knob to select a program within a bank.
The positions of this bank's algorithms cannot be changed. When using MIDI control, this bank responds to PC 00-10 (as noted in brackets).
The positions of this bank's algorithms cannot be changed. When using MIDI control, this bank responds to PC 11-21 (as noted in brackets).
This bank contains user-selected programs (and their respective algorithms) arranged in arbitrary order. Each of the programs can be altered by the user (including changing the algorithm). When using MIDI control, this bank responds to PC 22-32 (as noted in brackets).

Detune Mode (Gradual Signal Detuning)

To enter Detune mode, press and hold the ON/DETUNE footswitch for at least 0.3 seconds. While in Detune mode, the processed signal will be gradually detuned. The DETUNE knob controls the depth of the detuning effect.

With this mode, you can achieve various effects with nice-sounding quirks (e.g. guitar whammy bar simulation, tape speed up / slow down, or old-sampler-like pitch shifting). The effect's attack rate is 8 times slower than its release rate, which results in a more organic sound. If you hold down the DETUNE footswitch long enough, the detuning will reach the end of its range and start moving back, creating extra digital artifacts in the process.

Quick Access

The pedal's interface implements the Quick Access function, which allows you to quickly recall the first program in the UD bank. This way, you can instantly switch between the currently selected program and the first memory slot of the "favorites" bank. If you find yourself using a particular program very often, it's a good idea to save it as the first program in the UD bank: this way, you can swiftly recall it whenever you like.

To recall the Quick Access program or to exit from it, briefly press the ON footswitch twice. If the LED above the ON footswitch glows green, it indicates that the Quick Access program is active. If the Quick Access program has been recalled but the pedal is bypassed, the ON LED flashes repeatedly: this way you can tell which settings will be used once you turn the pedal on.

Saving a program to the Quick Access slot is done in the exact same way as saving any other program (please see the Program Management section for details).

You can set the CTRL input to control the Quick Access function. To do that, enter Setup Mode or change the settings in the USER.SET config file. You can also disable the Quick Access function. Please see the support page for details regarding Quick Access configuration.

External Parameter Control

The CTRL stereo input allows you to set up external control over the pedal's parameters. It has several operation modes:
  1. Passive controller (normally open momentary button). This mode controls the pedal's footswitches (TIP — TAP/ALT, RING — ON/DETUNE).
  2. MIDI (Type A) control over all parameters. This mode is selected by default.
  3. S-trigger. "Short circuit trigger", analog trigger/gate with the same polarity as the pedal's. This is the recommended trigger type. The TIP contact controls the TAP function, while the RING contact controls the DETUNE function.
  4. V-trigger. "Voltage trigger"/"positive trigger", analog trigger/gate with polarity opposite to the pedal's. If no external signal is coming into the CTRL input, the ALT LED will light up and some of the pedal's functions will be inactive. Those functions become active as soon as the control signal is connected. The TIP contact controls the TAP function, while the RING contact controls the DETUNE function. Use this trigger type if you have no S-trigger source or if you prefer V-triggers for other reasons.
  5. Passive expression pedal. This mode allows you to control one of the pedal's knobs (FREQ by default) via an expression pedal. Expression pedals with TS connections are recommended.
  6. Passive controller (normally open momentary button) or analog S-trigger. The TIP contact controls the Quick Access function, while the RING contact controls the TAP function.
Please see the support page for details regarding CTRL configuration.


  • LEFT IN / RIGHT IN: 6.3 mm, mono, unbalanced, 1 MOhm input impedance. LEFT IN is the main mono input.
  • LEFT OUT / RIGHT OUT: 6.3 mm, mono, unbalanced, 100 Ohm output impedance. LEFT OUT is the main mono output.
  • CTRL: 6.3 mm, stereo. Accepted control sources: normally open momentary button, MIDI Type A, 5 V analog trigger (S-Trigger/V-Trigger), passive expression pedal (TS or TRS, 10-25 kOhm).
  • Power: 2,1/5,5 mm, negative tip.
    • 9V DC 200 mA.
    • 12V DC 160 mA.
The pedal can't be battery-powered. Use a regulated PSU only.

  • Dimensions (LхWхH): 110х104х56 mm (4.3x4.1x2.2").
  • Weight: 350 g (0.77 lbs).

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