Sample accurate clock from a DAW? (Like Usamo/Multiclock/Midronome/etc)


I was wondering if the following is possible:

Use one of Hapax’ CV inputs as the clock source, while sending a pulse from a DAW (via one of your audio interface outputs) to the Hapax.

Then set the Midi start/stop setting to On (any input). Also connect the Hapax to the DAW using USB. Make your DAW send start/stop (and clock probably, but this will be ignored) messages to the Hapax.

So in theory, the Hapax should now respond correctly start/stop (and reset/continue?) midi messages received by the usb connection, but ignore the midi clock and use the audio pulses instead for a tight (sample accurate?) clock.

This is exactly how Midronome does it (which also needs a separate midi start/stop message via usb AFAIK) while syncing the clock to the audio signal.

I hope someone can confirm/debunk this theory, so that would save me some time testing, otherwise I will just test it myself and report here :slight_smile:

Yup, this could potentially work fine depending on your setup. You don’t need to use USB for reset/transport.

It works for me like this:

  • Send clock from my DC coupled audio interface (Quantum 26x26) to CV1
  • Send reset (bitwig) or transport (ableton) from Quantum to CV2
  • Use Ableton CV Tools or Bitwig HW clock out

One thing to note, is that the BPM display on HAPAX doesn’t change, which is really frustrating. If I move the bpm from 120 to 130 in Ableton, HAPAX will still show 120, even though it definitely moved to 130.

I don’t know if an audio file would work with an AC coupled interface since the signal is likely too weak*. I also don’t know if it would work with a DAW other than Bitwig or Ableton (not aware of CV utilities for other DAWs).

*ERM Multiclock and similar devices likely remove the DC component, bias/amplify the signal, maybe condition it in some way (comparator, schmitt trigger, etc) before heading into some microcontroller to do the magic. I’d be surprised if HAPAX did any of that. But, this circuit seems simple, and I’m surprised sequencers don’t just include it along with an audio jack for clocking.