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MIDI setup

NullPerator treats MIDI input and output as separate paths. The Device page's MIDI DEVICE row controls output routing wherever that row is shown; it does not turn incoming notes or transport messages on and off. iOS chooses both routes in the app's MIDI settings instead.

NullPerator hardware​

TRS output​

  1. Connect the NullPerator hardware MIDI OUT jack to the receiving device.
  2. On Device, set MIDI DEVICE to TRS.
  3. Create a MIDI instrument and set its channel from 1 to 16.
  4. Enter notes with that instrument in a Phrase and start playback.

Use TRS for MIDI output on NullPerator hardware 0.1. The USB route is not available in this version.

TRS input​

The NullPerator hardware MIDI IN jack starts with the application and is independent of the output selector. Incoming channels 1–16 address instrument slots 00–0F in order. For example, channel 1 auditions instrument 00 and channel 16 auditions instrument 0F.

Up to eight incoming notes can be previewed at once.

Web app​

Browser MIDI requires the Web MIDI API and a user gesture:

  1. Open the Web app's MIDI panel.
  2. Press Enable Web MIDI and grant the browser permission.
  3. Select an input and/or output from the browser device lists.
  4. For output, leave MIDI DEVICE on any non-OFF value.

The Web app remembers the selected device and waits for it to reconnect. If the Web MIDI panel is missing or unsupported, try a browser with Web MIDI support on a secure or local site.

iOS app​

  1. Open the app settings and choose MIDI.
  2. Turn on Enable MIDI.
  3. Choose a CoreMIDI input and/or output.
  4. To use a Bluetooth device, open Bluetooth MIDI there and pair it first.
  5. Return to the tracker; no MIDI DEVICE row is shown on iOS.

iOS remembers the selected endpoints and reconnects when they become available. MIDI accessories connected through iOS and paired Bluetooth MIDI devices appear in the same input and output lists.

Send transport clock​

Set MIDI SYNC to ON to keep an external device in time with NullPerator. It sends MIDI Clock while playing, plus Start and Stop messages.

This is send-only sync: incoming MIDI Clock does not change NullPerator's tempo. Incoming Start, Stop, and Continue can still control playback.

NullPerator does not send song position. Set the receiving device to the right position before starting if it needs an absolute timeline.

See MIDI capabilities for the complete message matrix and the commands available to MIDI instruments.