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

àradh

Instruō

Transistor ladder lowpass filter with integrated VCA (pre/post-filter routing), envelope follower, comparator gate output, strike input with variable decay, and user-definable CV parameter assignments. Self-oscillating resonance with auto-gain compensation.470

Capabilities 6

Comparatorcomparator
Comparator threshold set via Bias knob hold-gesture. Gate output range 0V to +5V.470
Envelope Followerenvelope-follower
Envelope follower derived from pre- or post-filter signal (configurable). Attack time set via Q knob hold-gesture; decay time via Decay Knob. Output range ≈0V to +8V.470
Lowpass Filterlowpass-filter
470
Transistor Laddertransistor-ladder
470
Vcfvcf
470
Voltage-Controlled Amplifiervca
Integrated VCA with configurable pre- or post-filter routing via panel switch; unity gain at centre Bias Knob with no CV, or at ~3.6V CV with attenuverter fully clockwise.470

Jacks 6 — 4 in / 2 out

NameSignalVoltageDescription
Inputs (4)
1V/Oct InputcvBipolar 1V/oct CV input for keyboard tracking; sums with the Filter Cutoff Knob to set cutoff frequency.470
CV InputcvBipolar CV input routed to user-assigned parameter(s): VCA amplitude, filter cutoff, resonance, and/or impulse decay. Scaled by CV Attenuverter. Normalled to envelope follower or gate signal when no patch cable present.470
InaudioAC coupled audio input to the lowpass filter and VCA.470
Strike InputgateGate/trigger input for the impulse envelope; rising edges trigger a decay envelope modulating filter cutoff and VCA amplitude. Can be triggered at audio rate.470
Outputs (2)
Gate/Follow OutputmixedOutputs either the comparator gate signal or envelope follower signal depending on the Gate/Follow Toggle position. Envelope follower range ≈0V to +8V; comparator gate range 0V to +5V.470
OutaudioAC coupled audio output from the lowpass filter and VCA.470

Parameters 9

NameTypeRangeBehavior
Bias KnobknobSets the VCA level. Unity gain is achieved at centre position with no CV. Also sets the comparator threshold voltage via hold-gesture.470
CV Assign ButtonbuttonPress to cycle through primary user-defined parameter targets (unlit=none, white=VCA amplitude, amber=filter cutoff, white/amber=both). Hold + Strike Button for secondary parameter assignment and other functions. Setting is retained between power cycles.470
Assignable destinations
None470 VCA Amplitude470 Filter Cutoff470 VCA Amplitude + Filter Cutoff470
CV AttenuverterknobScales and inverts the CV Input signal. CW increases modulation depth; CCW increases modulation with inverted polarity; centre fully attenuates. Unity gain of VCA is achieved when fully CW with ~3.6V at CV Input.470
Decay KnobknobControls decay time of the impulse envelope; CCW decreases decay, CW increases decay. Also sets decay time of the envelope follower.470
Filter Cutoff KnobknobControls the cutoff frequency of the lowpass filter; CW increases, CCW decreases. When self-oscillating, controls the oscillator frequency. Sums with 1V/Oct CV input.470
Gate/Follow Toggleswitch470
Pre/Post SwitchswitchUpward position: VCA post-filter (east-coast routing). Downward position: VCA pre-filter (allows filter saturation). Also determines whether the envelope follower taps the pre- or post-filter signal.470
Resonance KnobknobSets filter resonance/Q; fully CW produces self-oscillation generating a sine wave. Auto-gain compensation maintains consistent output level as resonance increases. Also sets attack time of envelope follower via hold-gesture.470
Strike ButtonbuttonManually triggers the impulse envelope. Also used in combination with CV Assign Button for secondary parameter assignment, envelope follower configuration, and factory reset.470

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [470]
    Instruō àradh User Manualmanual
    verified 2026-05-17
  2. [471]
    Instruō àradh product pageproduct_page
    ⚠ verified 2026-05-17 · manufacturer changed since last verified