Eurorack Reference / modules /instruo/arbhar audit site v0.1 — milestone 3
instruo/arbhar

arbhar

Instruō

18 HP granular audio processor with two granular engines supporting up to 88 polyphonic grains, six 10-second audio buffers, built-in condenser microphone, USB import/export, and Scan Mode, Follow Mode, and Wavetable Mode.297

Capabilities 4

Audio Capture / Looperaudio-capture
Records up to 10 seconds per layer into six independent layers; supports overdub, accumulative record, and USB import.297
Granular Synthesisgranular-synthesis
Two granular engines (Continuous and Strike) generating up to 88 polyphonic grains total; 44 grains each by default.297
Onset Detectiononset-detection
Six onset control modes (alpha–zeta) that detect spectral changes to trigger recording and/or generate pulse signals at the Pulse Output.297
Wavetable Oscillatorwavetable-oscillator
Wavetable mode derived from recorded layer content; pitch calibrated to C2 by default.297

Jacks 19 — 16 in / 3 out

NameSignalVoltageDescription
Inputs (16)
1V/Oct Inputcv-5V to 5V297
Capture Pulse Inputgate297
Dry/Wet CV Inputcv-5V to 5V297
Dub CV Inputcv-5V to 5V297
Grain Direction CV Inputcv-5V to 5V297
Grain Window CV Inputcv-5V to 5V297
InputaudioAC coupled audio input. Input level set by the Input Level Knob. Analogue limiting prevents digital clipping. Normalled from Condenser Microphone via Onset Input.297
Intensity CV InputcvBipolar CV input summed with Intensity knob. Input range: 10Vpp.297
Layer CV Inputcv-5V to 5V297
Length CV Inputcv-5V to 5V297
Mod CV Inputcv297
Onset InputaudioAC coupled audio input for onset detection; normalled to the main Input. Can be configured as stereo right input in Stereo Input Mode.297
Pitch Deviation CV Inputcv-5V to 5V297
Scan CV Inputcv-5V to 5V297
Spray CV Inputcv-5V to 5V297
Strike Inputtrigger297
Outputs (3)
Output 1audio297
Output 2audioNormalled to Output 1 for mono playback. Connecting enables stereo imaging. Phase polarity can be set to phase-inverted (default) or phase-corrected.297
Pulse Outputmixed≤5VOutputs trigger or gate signals depending on the selected Onset Control Mode. Trigger signals are 10ms; gate signals are held for the Hold Knob duration.297

Parameters 18

NameTypeRangeBehavior
Capture ButtonbuttonActivates recording into the selected layer. By default, starts from the beginning of the layer. Recording stops automatically when layer is filled or when button is pressed again.297
Dry/Wet KnobknobEqual power crossfade between the dry signal and the granular engines.297
Dub KnobknobSets attenuation of existing layer audio when overdubbing. Fully anticlockwise = full replacement; center = existing at 50% mixed with new at 100%; fully clockwise = existing at 100% summed with new at 100%.297
Grain Direction KnobknobSets probability percentage of grain playback direction. Center = 50% forward / 50% reverse; fully anticlockwise = 100% forward; fully clockwise = 100% reverse. In Wavetable Mode, influences interpolation speed between wavetables.297
Grain Window KnobknobSets the grain amplitude envelope. Center = Gaussian (smooth drones/textures); anticlockwise morphs to square (sharp textures, loop effects); clockwise morphs to descending sawtooth (percussive textures).297
Hold Knobknob5ms – 10000msSets minimum record time when recording triggered by onset detection, or minimum time between pulse output signals upon onset. Also controls Follow Mode loop length. Exponential distribution; center position ~2.5 seconds.297
Input Level KnobknobSets the level of the signal at the Input, including the normalled Condenser Microphone signal. The input stage incorporates analogue limiting to allow saturation rather than digital clipping.297
Intensity KnobknobSets the amount and rate of grains from the Continuous Granular Engine. Center position generates maximum grains; turning anticlockwise or clockwise decreases grain count; extreme positions disable the Continuous Granular Engine.297
Layer KnobknobSelects the active layer (alpha through zeta, plus omega). When fully clockwise at omega, all layers are accessible via the Scan Knob. Also used with Shift to set Layer Record Destination Lock.297
Length Knobknob4ms – 3000msSets the duration of each grain. Follows exponential distribution; at centre position grain duration is 750ms. Turning fully anticlockwise crossfades into Wavetable Mode.297
Output Level Knobknob297
Pitch Deviation KnobknobApplies intervallic voltage offset to each grain's pitch. Turning clockwise from center applies bipolar quantized random pitch deviation of increasing intervals. In Wavetable Mode, functions in its normal manner.297
Pitch KnobknobChanges the pitch of grains. Values are applied at grain start and remain unchanged for grain duration, enabling polyphonic pitch layers when modulated.297
Scan KnobknobSets the position of grain generation within the layer. In Scan Mode, freezes playback at any position. In Follow Mode, becomes a speed control (20x to 1/20th speed).297
Sensitivity KnobknobSets onset detection responsiveness (mono mode) or Input 2 level (stereo mode). Anticlockwise decreases; clockwise increases.297
Shift Buttonbutton297
Spray KnobknobControls random deviation of grain offset position to the right of the current Scan position. At maximum value, grain start position is completely random throughout the entire layer.297
Strike ButtonbuttonGenerates a single grain from the Strike Granular Engine. Strike grains are 15% louder than Continuous Engine grains, acting as accents in dense textures. In Follow Mode, resets playhead to start of layer.297

Firmware history 1 version

VersionReleasedNotes
2.02023Complete rewrite of the entire codebase; implements technical and conceptual improvements, expanded features, and preserved overall feel. Introduces Scan Mode, Follow Mode, Wavetable Mode, six onset control modes, USB import/export, scene management, and Mod CV configurations.297

References 3

  1. [297]
    arbhar Granular Audio Processor Manual (Firmware 2.0)manual
    verified 2026-05-11
  2. [298]
    arbhar Quickstart Booklet (Firmware 2)manual
    verified 2026-05-11
  3. [299]
    Instruō arbhar product pageproduct_page
    ⚠ verified 2026-05-11 · manufacturer changed since last verified