MIDI-CV

Play the rack from a hardware MIDI controller. MIDI-CV turns a keyboard, pad controller, or sequencer into the rack's control voltages — pitch, gate, velocity, the wheels, and a full set of clock and transport triggers — modelled on VCV Rack's MIDI-CV.

It needs Web MIDI, which works in Chrome, Edge, and Firefox on desktop. Safari and iOS don't support it; there, use the on-screen Keyboard module instead.

How it works

Web MIDI is read on the main thread, where last-note-priority note logic runs, and the resulting voltages are streamed straight to the audio engine — so a stream of live notes never clutters undo history or the saved patch. Only the device, channel, and clock-division settings are saved with your patch.

Controls

  • Device — click to pick a MIDI input. The first time, your browser asks

permission to use MIDI. Pick — None — to disconnect.

  • Channel — listen on one MIDI channel (1–16) or Omni (all channels).
  • Clock ÷ — the musical division of the CLK/N output: 1/4 down to

1/32 (and triplets), derived from the incoming 24-PPQN MIDI clock.

  • The status strip shows a GATE lamp, the note currently playing, and a

CLK lamp that blinks with the incoming clock.

Outputs

  • V/OCT — 1V/oct pitch of the last held note (0 V = C4). Holds its value

when you let go.

  • GATE — 10 V while any key is held; it does not re-trigger on legato.
  • RTRG — a short trigger on every note-on, even legato — patch it to an

envelope's trigger to hard-sync each note.

  • VEL / AFT — velocity and channel-pressure (aftertouch) as 0–10 V CV.
  • PW / MW — pitch wheel (-5..+5 V) and mod wheel (0–10 V). The wheels

are gently smoothed so they don't add stepping ("zipper") noise.

  • CLK / CLK·N — a pulse per MIDI clock tick, and a divided clock set by

Clock ÷.

  • START / STOP / CONT — a trigger on MIDI Start, Stop, and Continue. Start

also resets the divided clock's phase.

Tips

  • Sum PW into a filter or oscillator's V/OCT (with an attenuator) to set

your own bend depth — MIDI-CV keeps it on its own jack so the patch decides.

  • Drive a clock-able module from CLK·N, and reset it from START so it

locks to your DAW's transport.