The 303 MIDI sequencer that drives your hardware

Stepsicle is a 303 MIDI sequencer for hardware and software synths. Program slide, accent and tie on each step. Their sound depends on the receiving synth and its settings.

An original TB-303 has no MIDI input. To sequence its notes externally, it needs a MIDI retrofit or added CV/Gate inputs with a compatible MIDI-to-CV interface. Stepsicle also has a built-in Acid Synth.

Slide, accent and tie on each step

Stepsicle puts slide, accent and tie beside each note. Edit these controls directly on the step strip instead of adjusting note lengths and velocities in a piano roll.

What a 303 MIDI sequencer has to get right

Stepsicle sends MIDI notes and velocity values. The receiving synth determines how they sound.

• Slide sends the new note before it releases the previous note. Use a synth with legato glide enabled to hear a slide.
• Accent uses the accent velocity configured in MIDI Output. Match the output profile and accent settings to your synth.
• Tie extends the previous note without sending a new Note On.

Sequence hardware and software synths

Send the same Stepsicle pattern to different MIDI synths. Use the CV version with compatible hardware, or use the built-in Acid Synth to hear a pattern without external routing.

Sixteen steps, twelve controls each

Every step carries note, velocity, gate length, slide, accent, rest, skip, tie, octave, nudge, note delay, and trigger probability. Editing is physical: drag a pad up for velocity, drag right for gate length, and push the gate past 100 percent to overlap the next step into a slide. Set step 5 to fire early with a 40 percent chance of playing while step 6 holds a tied note, and the line breathes instead of marching.

Patterns, chains, and scales

Build up to 128 patterns and chain them into a full arrangement. Each pattern keeps its own length, transpose of up to 36 semitones either way, rate division, and playback mode: forward, reverse, pendulum, or random. With 30 rate divisions covering straight, triplet, and dotted values from 1/32 to 16 bars, you can run a 1/16 pattern into a 1/8 reverse pattern into a 1/32 random one and let the rate follow at each boundary. A 17-mode scale filter keeps every note in key, with a per-step bypass when you want a chromatic passing tone.

Four ways to play it live

• Off runs the sequence on its own.
• Transpose shifts the whole pattern in real time from a MIDI keyboard.
• Note held = play runs the sequence only while you hold a key.
• Pattern select maps incoming notes to patterns so you can switch on the fly.

A Transport Gate overlay learns any note, so you drop in and out by holding it. Live Record captures notes and velocity straight from your keyboard. Every edit lands in a 1000-step undo history that saves with the project.

Drag patterns out as MIDI

When a line is right, drag it from Stepsicle into your DAW timeline as a Standard MIDI File at 480 PPQ. Shift-drag exports the whole chain at once. Swing from 0 to 100 percent, per-step nudge, and per-step note delay are baked into the exported notes, so the part arrives already grooved.

Questions

Pricing

Part of Stepsicle. Also available as an envelope shaper and a CV sequencer. One license includes all three, and every variant shares the same pattern format.