Eurorack Reference / modules /bastl-instruments/ikarie audit site v0.1 — milestone 3
bastl-instruments/ikarie

Ikarie

Bastl Instruments

Ikarie is a uniquely sculpted, flexible stereo or dual peak filter module. It can continuously transition between lowpass and highpass filtering with a single knob, and packs an envelope follower for the incoming audio signal. Two parallel 12dB/oct state variable filter cores can run in stereo, dual mono, or series (24dB/oct). Includes internal VCA, CV control over panning and resonance, optional input overdrive, and a Beyond output for the spectral difference (twin peak filter).189

Visualization filter_response

Capabilities 4

Envelope Followerenvelope-follower
Listens to L IN signal (post-INPUT knob), outputs CV normalled to MOD input. Three decay settings: SLOW, MID, FAST. Can be used for side-chain filtering by feeding signal only to R IN.189
Self-Oscillationself-oscillation
At maximum resonance with no input signal (or INPUT fully CCW), Ikarie self-oscillates producing a sine wave. Can be used as a pitched tone source calibrated via V/OCT input.189
Stereo Filterstereo-filter
Two parallel 12dB/oct state variable filter cores (Left and Right). Can run in parallel (stereo or dual-peak mono), or in series (L OUT → R IN) for 24dB/oct slope.189
Voltage-Controlled Amplifiervca
Internal VCA pair per filter used both for LP/HP switching and for controlling final output loudness via VCA CV input (0–5V).189

Jacks 11 — 7 in / 4 out

NameSignalVoltageDescription
Inputs (7)
L INaudioLeft audio input. Normalled to R IN when R IN is unpatched. Also monitored by the envelope follower section.189
MODcvCV input for cutoff modulation of both filters in tandem. FOLLOW output is normalled to this jack. Attenuverter knob controls amount and polarity.189
R INaudioRight audio input. Receives L IN signal via normalling when unpatched.189
RESONANCE CVcvCV input for resonance control. Without cable: fader is direct control. With cable: fader becomes attenuator setting the maximum resonance level the CV can reach.189
STEREOcvCV input for stereo modulation (panning or spread). When patched, STEREO knob becomes an attenuverter for the CV amount.189
V/OCTcvV/oct pitch CV input modulating both filters in sync. Scaling trimmer accessible from front panel for calibration.189
VCA CVcv0V to 5VCV input controlling output VCA level. With no cable patched, filter runs at unity. When patched, 0V = silence, 5V = unity gain.189
Outputs (4)
BEYONDmixedOutputs the spectral difference of the two filter signals (L minus R), acting as a twin-peak or bandpass filter output. Can also serve as a ring modulator output when STEREO is modulated at audio rate in PAN mode.189
FOLLOWcvEnvelope follower CV output, normalled to MOD input. Tracks amplitude of L IN signal. Can be patched to any Ikarie parameter for dynamic control.189
L OUTaudioLeft filter output. When used alone (mono), provides sum of both left and right filter channels as parallel dual-peak filtered output.189
R OUTaudio189

Parameters 7

NameTypeRangeBehavior
CUTOFFknobCenter position gives an open (flat) filter. Turning CCW sweeps into lowpass mode (cuts high frequencies). Turning CW sweeps into highpass mode (cuts low frequencies). Can be offset by CV from MOD, V/OCT, or STEREO inputs.189
FOLLOW switchswitchThree-position switch setting envelope follower decay: SLOW (natural release, pumping effects), MID (tighter, best for mid-range signals), FAST (near-instantaneous, full-wave rectifier character).189
INPUTknob0x gain – 5x gainControls input gain from silence to 5x. Mid position gives clean balanced resonance; fully CW gives overdriven character that retains bass while keeping resonant sweep in HP setting. Also amplifies line-level signals to optimal filter operating level.189
MOD attenuverterknobAttenuverter for the MOD CV input affecting cutoff. Center = no modulation. CW = positive modulation of cutoff. CCW = inverted modulation of cutoff.189
RESONANCEfaderEmphasises the cutoff frequency, up to full self-oscillation producing a sine wave. Higher resonance makes the filter an unstable resonator useful for pinged sounds. When a CV cable is plugged in, the fader becomes an attenuator setting the maximum CV-reachable resonance level.189
STEREOknobIn SPREAD mode: detunes left and right filter cutoffs (CW increases left, decreases right; CCW opposite). In PAN mode: pans left/right output levels (or crossfades L/R inputs in mono). When CV is patched to STEREO jack, knob becomes attenuverter for CV amount.189
STEREO switchswitchTwo-position switch selecting SPREAD (detunes the two filter cutoffs) or PAN (controls relative output levels of left and right filters) mode for the STEREO knob and CV input.189

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [189]
    Ikarie Twin Auto Filter Manualmanual
    verified 2026-05-06
  2. [190]
    Bastl Ikarie product pageproduct_page
    ⚠ verified 2026-05-06 · manufacturer changed since last verified