Clock Sync

To play in time with a DAW, drum machine, or another sequencer, Resonon can share a MIDI clock — either driving everything as the master, or following an external source. This guide covers the virtual-port setup you need first, then both clock modes, and finally syncing with a DAW.

Note

These snippets are shown syntax-only — clock sync needs real MIDI ports and devices, which a documentation build doesn’t have. Run them in a live session with your gear or DAW connected.

Setting Up a Virtual MIDI Port

Clock sync rides over a MIDI port shared between Resonon and the other application. On most systems that means a virtual port.

macOS (IAC Driver)

1. Open Audio MIDI Setup (Applications → Utilities).
2. Choose Window → Show MIDI Studio (Cmd+2).
3. Double-click IAC Driver, check Device is online, and make sure at least one port exists (default: “Bus 1”).
4. Click Apply.

Windows (loopMIDI)

Install loopMIDI and create a virtual port (e.g. “loopMIDI Port”).

Linux (ALSA / JACK)

Use an ALSA or JACK virtual MIDI port from your audio setup.

Confirm the port is visible to Resonon:

print(midi_ports());        // "IAC Driver Bus 1" (or your virtual port) should appear

resonon --list-ports        # same, from the command line

Master Mode — Sending Clock

midi_clock_send(true) makes Resonon the clock master: it emits 24-PPQ clock ticks to all connected output ports, alongside Start, Stop, and Continue transport messages.

midi_connect("IAC Driver Bus 1", "daw");
midi_clock_send(true);
setbpm(120);
PLAY;

Disable it with midi_clock_send(false). In your DAW, set the transport to follow external MIDI clock on the same port and it will lock to Resonon’s tempo.

Follower Mode — Following Clock

midi_clock_follow(alias) syncs Resonon’s tempo and transport to an external clock arriving on a connected input port:

midi_input_connect("DAW Output", "daw");
midi_clock_follow("daw");

While following:

• Tempo is derived by averaging 24 ticks (one quarter note).
• Start resets playback to the beginning; Stop pauses; Continue resumes.
• A soft PLL applies phase correction (up to ~1 ms per quarter note) to stay tightly locked.

Turn it off by passing false:

midi_clock_follow(false);

Mutual exclusivity

Clock send and clock follow can’t both be active — enabling one disables the other.

Output Delay & Clock Offset

Two knobs align MIDI with your audio and with external gear:

midi_delay(ms) delays all outgoing MIDI — notes and clock. Use it to compensate for audio output latency so MIDI and audio stay aligned:

midi_delay(15);         // delay all MIDI output by 15ms
print(midi_delay());    // getter: prints 15

midi_clock_offset(ms) shifts only clock ticks — positive delays them, negative sends them earlier — independent of midi_delay(). The total delay on ticks is midi_delay() + midi_clock_offset():

midi_delay(15);            // all MIDI delayed 15ms
midi_clock_offset(-5);     // clock ticks shifted 5ms earlier
// Effective clock delay: 15 + (-5) = 10ms
// Effective note delay:  15ms

Function	Description
midi_clock_send(true / false)	Enable / disable 24-PPQ clock output (master mode)
midi_clock_follow(alias / false)	Follow / stop following external clock (follower mode)
midi_delay(ms) / midi_delay()	Set / get global MIDI output delay (notes + clock)
midi_clock_offset(ms) / midi_clock_offset()	Set / get clock-only offset

Troubleshooting

Error	Cause	Fix
No MIDI input connected with alias '...'	midi_clock_follow with an unknown alias	Connect the input first with midi_input_connect()
Tempo drifts or won’t lock	No clock arriving, or wrong port	Confirm the source is sending clock and check midi_routing()
Clock send has no effect	Nothing follows the port	Set your DAW’s transport to follow external MIDI clock

midi_routing() prints the current clock state (mode: master (sending) or mode: follower (from "...")) — check it first when sync misbehaves.

Syncing With a DAW

Any DAW that accepts external MIDI input can play instruments driven by Resonon over the virtual port. The steps are the same everywhere:

1. Open your DAW’s MIDI preferences and enable the virtual port as an input.
2. Create an instrument track and load a synth or plugin.
3. Set the track’s MIDI input to the virtual port (or “All Inputs”) and enable input monitoring.
4. Send notes from Resonon:

midi_connect("IAC Driver Bus 1", "daw");

let t = MidiTrack(1);
t << [C4 E4 G4 E4];
PLAY;

To record Resonon’s output as MIDI clips, arm the DAW track and press record before running your code.

Note

Some DAWs (like GarageBand) auto-detect virtual MIDI ports — no configuration needed beyond creating an instrument track.

Multiple channels

Drive several DAW instruments at once by putting each on its own channel:

midi_connect("IAC Driver Bus 1", "daw");

let drums = MidiTrack(10);    // channel 10 (GM drums)
let bass  = MidiTrack(1);
let lead  = MidiTrack(2);

In the DAW, create one track per channel listening to the shared port.

Next Steps

Synced and playing — now get your work out as files.

• Export & MPE — write Standard MIDI Files
• MIDI In & CC — bring notes and controllers back in
• Troubleshooting — fixes for common issues