Instruo Arbhar
Real-time granular processor with six layers and 88 grains
18 HP Eurorack module
The arbhar is a real-time granular audio processor for Eurorack that captures incoming audio into six 10-second layers and processes them through two independent polyphonic granular engines capable of up to 88 simultaneous grains. It excels at creating frozen drones, spectral smearing, time-stretching, wavetable synthesis, and acousmatic textures from any audio source, with deep CV control and onset detection for reactive, performance-driven granular processing.
Features
- Up to 88 simultaneous polyphonic grains across two independent granular engines
- Six 10-second audio buffer layers (alpha, beta, gamma, delta, epsilon, zeta)
- Continuous Granular Engine with Intensity/Length control and up to 44 grains
- Strike Granular Engine triggered by Strike Button or Strike Input, up to 44 grains, 15% louder for accenting
- Omega layer links all six layers for seamless scanning across the entire buffer
- 1V/octave pitch tracking input
- Grain Window morphs from square to Gaussian to sawtooth
- Grain Direction probability from 100% forward to 100% reverse per grain
- Spray Knob for random grain offset deviation with wrap-around
- Scan Mode for frozen playback position and Follow Mode for independent speed/pitch control
- Wavetable Mode derived from single-cycle loops of recorded content
- Audio analysis with onset detection for automatic capture triggering
Controls & Jacks (31)
- Sensitivity — Sets the sensitivity threshold for the onset detection algorithm used to trigger automatic audio capturing.
- Capture — Activates recording of the signal present at the Input (and Onset Input in Stereo Input Mode) into the audio buffer.
- Pitch Deviation — Sets the amount of random pitch deviation applied per grain, spreading grains across a pitch range.
- Layer — Controls the number of simultaneously sounding granular layers/grains across both granular engines.
- Length — Sets the length/duration of each individual grain.
- Spray — Sets the random scatter of grain read positions around the current Scan position within the audio buffer.
- Grain Window — Sets the shape/envelope window applied to each grain, controlling the attack and decay of grain amplitude.
- Intensity — Controls the intensity of grain generation, affecting grain density and triggering rate.
- Scan — Controls the position within the audio buffer from which grains are read; in Scan Mode continuously moves the read position.
- Pitch — Sets the base pitch/playback speed of the grains; tracks 1V/octave via the 1V/Oct input.
- Pulse Output — Outputs a trigger pulse each time a new grain is generated by the granular engine.
- Onset Input — Audio input used for onset detection to trigger automatic audio capturing. Normalled from the condenser microphone; normalled to the main In
- Capture Pulse Input — Gate or trigger input that activates the capture/record function externally, equivalent to pressing the Capture Button.
- Length CV Input — CV input that modulates the Length knob, controlling the duration of each grain.
- Shift — Shift function button used to access secondary parameters and alternate modes of the module.
- Hold — Controls the hold time after a capture event before the granular engine is allowed to update its buffer position.
- Input — AC coupled audio input for capturing external audio into the granular buffers. Normalled from the condenser microphone via the Onset Input.
- Output 1 — Primary audio output. In mono use, monitor from this output. Output 2 is normalled to Output 1 when unpatched.
- Grain Direction — Controls the probability of grain playback direction, ranging from always forward to always reverse.
- Strike Input — Trigger input that fires the granular engines, equivalent to pressing the Strike Button.
- Spray CV Input — CV input (on CV Expansion module) that modulates the Spray knob, controlling random scatter of grain read positions.
- 1V/Octave Input — 1V/octave pitch CV input for tracking melodic sequences and transposing grain playback pitch.
- Dry/Wet Mix — Equal power crossfade between the dry input signal and the granular engines' output.
- Output Level — Sets the overall level of the signal present at the Outputs.
- Input Level — Sets the level of the signal at the Input, including the normalled condenser microphone signal. Unity gain at approximately 10:00 position;
- Scan CV Input — CV input that modulates the Scan knob, controlling the read position within the audio buffer.
- Dub — Controls the dub/overdub level, mixing new incoming audio with previously captured audio in the buffer.
- Intensity CV Input — CV input that modulates the Intensity knob, controlling grain density and triggering rate.
- Record
- Input LED
- Output 2 — Secondary audio output. When patched, enables stereo imaging and independent effect processing. Output 2 is normalled to Output 1 when unpat
How-To Guides
- Granular Freeze Drone
- Auto-Capture Onset Looper
- Independent Pitch and Speed Timestretch
- Recorded Wavetable Oscillator
- Granular Polyphonic Harmonizer
- Karplus-Strong Granular Plucks
- Six-Layer Live Sample Player
- Accumulative Audio Collage
- Infinite Reverb Shimmer Pad
- Save a Scene to USB
- Load a Scene from USB
- Load Audio into a Layer from USB
Explore the interactive Arbhar panel on BleepDex — tap any control to learn what it does.
