bastl-instruments-ikarie

Bastl Instruments Ikarie

Dual-core stereo filter with formant soul and cosmic range

8 HP Eurorack module

Ikarie is a flexible stereo or dual-peak filter module featuring two parallel 12dB/oct state variable filter cores that can continuously sweep between lowpass and highpass with a single knob. It includes a built-in envelope follower, voltage-controlled resonance, input overdrive, stereo VCA, and a unique Beyond output that delivers the spectral difference between the two filters. The module excels at vocal formant tones, twin-peak filtering, self-oscillation, percussive pinging, and experimental stereo sound design.

Features

  • Two parallel 12dB/oct state variable filter cores (left and right)
  • Continuous lowpass to highpass sweep via single CUTOFF knob
  • Unique VCA-based LP/HP switching topology
  • Stereo or dual-peak mono operation
  • BEYOND output for spectral difference (twin-peak filter)
  • Envelope follower with three decay/speed settings (Slow, Mid, Fast)
  • Envelope follower normalized to MOD input for auto-filter/auto-wah
  • Input gain from unity to 5x overdrive
  • Voltage-controlled resonance with fader as attenuator when CV connected
  • MOD input with attenuverter for bipolar CV modulation of cutoff
  • V/OCT input for pitch-tracking with front-panel accessible scaling trimmer
  • STEREO section with SPREAD (cutoff detuning) and PAN (level panning) modes

Controls & Jacks (26)

  • Input— Controls input level from silent to 5x gain. Affects filter character and sensitivity; mid-way provides clean balanced resonances, extreme s
  • Mod— Attenuverter for MOD input controlling CUTOFF of both filters. Center position blocks modulation; CW opens positive modulation, CCW inverts
  • Stereo— Controls stereo spread/pan effects. In SPREAD mode: detuning between left and right cutoff frequencies. In PAN mode: panning or crossfading
  • Cutoff— Continuously transitions between lowpass (CCW) and highpass (CW) filtering. Center position is open filter. Voltage controlled via CV MOD, V
  • Follow— Envelope follower output tracking loudness of left input signal. Selectable responsivity (Slow/Mid/Fast). Normalized to MOD input for auto-f
  • L In— Left channel audio input; normalizes to R In
  • R Out— Right filter output; can receive L Out for serial 24dB filtering
  • Mod— CV input modulating CUTOFF of both filters in tandem. FOLLOW output is normalized here unless overridden by patch cable.
  • V/Oct— Volt-per-octave pitch control for both filters
  • Stereo— CV input for stereo modulation. Modulates SPREAD or PAN mode depending on switch setting. Knob becomes attenuator when cable connected.
  • L Out— Left filter output; use alone for mono or with R Out for stereo
  • VCA CV— Output level control via internal VCA (0-5V)
  • R In— Right channel audio input; normalized from L In
  • Beyond— Spectral difference output between two filters. Creates twin peak/bandpass behavior or ring modulation effects when combined with PAN mode.
  • Follow Speed— Selects envelope follower responsivity: Slow (natural pumping), Mid (tight, mid-range), or Fast (hard edge, full-wave rectifier).
  • Stereo Mode— Selects between SPREAD (detuning filter frequencies) and PAN (level panning/crossfading) modes for stereo control.
  • RESONANCE— Fader emphasizing CUTOFF frequency with partial or full self-oscillation. Acts as main control when no CV is patched; becomes attenuator for
  • RESONANCE CV— input jack
  • STEREO— Selects between SPREAD (detuning filter frequencies) and PAN (level panning/crossfading) modes for stereo control.
  • FOLLOW— Selects envelope follower responsivity: Slow (natural pumping), Mid (tight, mid-range), or Fast (hard edge, full-wave rectifier).
  • V/OCT trimmer— Rear-panel flathead screw trimmer to calibrate V/OCT tracking scaling
  • Mod CV— Modulation input for CUTOFF; FOLLOW normalized here
  • MOD input— Modulation input for CUTOFF; FOLLOW normalized here
  • STEREO CV— Modulation for SPREAD or PAN stereo effects
  • FOLLOW output— Envelope follower output tracking left input loudness
  • BEYOND output— Twin peak filter / spectral difference output

How-To Guides

  • Vocal Formant Filtering
  • Quad Acid Sweep
  • Beyond Stereo Imaging
  • Percussive Pinging
  • Self-Oscillating Sine Generator
  • Auto-Filter / Auto-Wah
  • Post-Filter Ring Modulator
  • Aggressive 24dB Series Filter
  • Waveform Crossfading
  • Sidechain Auto-Filter

Explore the interactive Ikarie panel on BleepDex — tap any control to learn what it does.

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