Stepsicle

A 303 line depends on how notes connect. Stepsicle drives a TD-3, a TB-303 MIDI setup, any hardware synth, or any soft synth that responds to velocity and overlapping notes.

• Slide: overlapping notes trigger the destination’s own portamento behavior.
• Accent: velocity 110 crosses the TD-3/TB-303 accent threshold while ordinary steps remain below it.
• Tie: the previous note continues without a fresh attack.

Stepsicle is the sequencer rather than a fixed synth voice. One pattern can play the box on your desk, a software instrument, the built-in Acid Synth for quick monitoring, or a modular oscillator through CV.

Build up to 128 patterns and chain them into arrangements. Every pattern keeps its own settings:

• Length, and transpose up to 36 semitones in either direction.
• Rate: thirty straight, triplet, and dotted divisions from 1/32 through 16 bars.
• Forward, reverse, pendulum, or random playback.
• A 17-mode scale filter keeps notes in key, with per-step bypass for chromatic movement.

Four MIDI performance modes let the sequence run freely, transpose from a keyboard, play only while a note is held, or select patterns from incoming notes.

• A learned Transport Gate drops the sequence in and out.
• Live Record captures notes and velocity.
• The 1000-step undo history is stored with the project.

Instead of looping one LFO shape, Stepsicle lets every step carry its own breakpoint curve. Run up to 16 envelope slots per pattern. Each slot can:

• Follow the sequencer.
• Use one of 30 synced divisions.
• Free-run in hertz, or use its own BPM.

Linear, exponential, logarithmic, and S-curve segments can start from 24 built-in shapes or a saved custom shape.

Fifteen zero-delay-feedback filters include ladder, diode, and state-variable low-pass, high-pass, band-pass, and notch designs. Drive, low-end fatness, RAT, Tube, Hard Clip, and Fuzz stages can sit around the filter with up to 8x oversampling.

A reorderable effects chain adds bitcrusher, stutter, tape stop, and stereo width.

• Switch an effect to per-step control and its settings follow the selected step.
• Envelope slots can also send MIDI CC, so the same shapes can animate external instruments.

Analog oscillators and audio interfaces do not track voltage perfectly. Stepsicle sweeps the connected oscillator, measures the returned pitch with two detection methods, and builds a 128-point correction table for that instrument. Save profiles per synth or store the calibration with the DAW project.

Route up to 18 CV outputs: pitch, gate, and up to 16 envelope voltages.

• Pitch: 1V/oct, linear, and Hz/V.
• Voltage ranges: ±5V, ±10V, 0 to 5V, and 0 to 10V.
• Settings: portamento, gate level, V-trig or S-trig, accent boost, DC offset, and whether rests output zero or hold the previous voltage.

CV requires a DC-coupled interface. Expert Sleepers ES-series hardware and compatible MOTU, RME, and Antelope outputs are suitable; AC-coupled consumer outputs cannot hold the required voltage. In CV mode, connect those outputs only to synth or modular CV inputs, not mixers, monitors, or headphones.

Drag the current pattern into the DAW as a Standard MIDI File at 480 PPQ, or Shift-drag the complete chain. Swing, nudge, and note delay are baked into the exported notes.

The built-in API and MCP server expose patterns, steps, envelopes, routing, and generation tools to scripts and compatible assistants. Use them to build or transform patterns, apply rhythm and groove ideas, and automate repeatable setup without replacing hands-on editing.

• Acid synth plugins provide their own oscillator and filter character; Stepsicle concentrates on sequencing and can drive those instruments or external hardware.
• Envelope tools repeat one curve, while Stepsicle can draw a different curve on every step across up to 16 independently clocked slots.
• MIDI-to-CV tools translate notes, while Stepsicle adds sequencer-aware slide, accent, tie, per-step envelope voltages, and VCO auto-calibration.

The practical difference is consolidation: one pattern format can move from a MIDI synth to an audio-effects chain or a calibrated modular patch without buying or learning separate Stepsicle tiers.