bastl-instruments/crust

Crust

Bastl Instruments

A hard-hitting drum voice consisting of two layers — a NOISE source and dual-oscillator TONE generator — with pitch envelope, layer mixing, FM envelope, transient shaper, and hard-clipping output stage.665

Capabilities 3

2-Operator FM Synthesisfm-synthesis
Four TONE modes including FM (2-operator), FM2 (FM with feedback), RING, and DUAL, all in the dual-oscillator TONE layer.665
Drum Voicedrum-voice
Dual-layer drum voice with NOISE source and dual-oscillator TONE generator, pitch envelope, FM envelope, transient shaper, and hard-clipping output stage.665
Envelope Generatorenvelope-generator
Generates TONE and NOISE amplitude envelopes output on ENV OUT (0–5V); also generates FM and pitch envelopes internally.665

Jacks 9 — 7 in / 2 out

NameSignalVoltageDescription
Inputs (7)
CTRL CVcv-5V to 5V665
Assignable destinations mirrors CTRL knob
OCTAVE665 SWEEP depth665
ENV CVcv-5V to 5V665
LAYER CVcv-5V to 5V665
PITCH V/OCTcv-5V to 8V665
TIMBRE CVcv-5V to 5V665
TRIGtrigger—665
VELOCITYcv—Adjusts envelope amplitude controlling loudness; when no cable is in TRIG, acts as a VCA input — rising voltage triggers internal envelopes.665
Outputs (2)
DRUMaudio—665
ENV OUTcv0V to 5V665

Parameters 9

NameTypeRangeBehavior
CTRL knobknob-6V – 6VAssignable control that acts as a static offset or attenuverter for CTRL CV. Adds its value to the target parameter's own fader/knob when assigned.665
Assignable destinations
OCTAVE665 PITCH exponential665 SWEEP depth665 SWEEP decay665 DETUNE665 TONE VCA(unipolar)665 TONE mode select665 DETUNE stepped665 LAYER665 ENV665 NOISE VCA(unipolar)665 NOISE mode select665 NOISE PITCH665 Noise FILTER cutoff665 CLIP665 SHAPE665 Noise FILTER resonance665
ENV knobknob—Macro controlling both TONE and NOISE amplitude envelopes. Center = shortest click; CW increases decay; CCW increases both attack and decay for synth/reversed timbres.665
Zones
Attack and Decay
Shortest Click
Decay only
  • Attack and Decay -100–0%Counter-clockwise from center increases both attack and decay, yielding synth-style envelopes on TONE and reversed envelopes on hi-hat.665
  • Shortest Click 0–0%Center position produces the shortest envelope click.665
  • Decay only 0–100%Clockwise from center increases decay time only.665
LAYER faderfader—Crossfades between TONE and NOISE layers by shortening the decay of amplitude envelopes on either side, enabling kick (tonal body/noisy transient) to snare/clap (noisy body/tonal transient) configurations.665
NOISE buttonbutton—Cycles through four NOISE modes: WHITE, BIT, CLAP, METAL. Also enables NOISE PITCH access when held while turning PITCH knob.665
PITCH buttonbutton—Single press cycles PITCH knob through OCTAVE, SWEEP, and DETUNE modes. Long press (>2s) enters TUNE mode.665
PITCH knobknob—Multi-function knob that switches between OCTAVE, SWEEP, and DETUNE modes via the PITCH button. Also accesses SEMI, FINE, and TUNE in TUNE mode.665
TIMBRE buttonbutton—Cycles through three TIMBRE parameter options: FILTER (noise LP/HP filter), CLIP (soft/hard clipping), and SHAPE (tone body/transient). Long press (>2s) enters CTRL assignment mode.665
TIMBRE faderfader—Controls character and intensity of FILTER, CLIP, and SHAPE. Center = inactive; left = body/bass-boost focus; right = transient focus.665
Zones
Body
Transient
  • Body -100–0%Left of center: body/bass-boost focus for FILTER, CLIP, and SHAPE parameters.665
  • Transient 0–100%Right of center: transient focus for FILTER, CLIP, and SHAPE parameters.665
TONE buttonbutton—Cycles through four TONE oscillator modes: FM, FM2, RING, DUAL. Also used in button combos for manual trigger and parameter adjustments.665

Firmware history 1 version

VersionReleasedNotes
1.1—665

References 2

  1. [665]
    Bastl Crust Manual (fw 1.1, rev. 2025-07-15)manual
    source 665 canonical ↗ archived ↗
    ● verified 2026-05-21
  2. [666]
    Bastl Crust product pageproduct_page
    source 666 canonical ↗ archived ↗
    ● verified 2026-05-21