MIDI Clock Start/stop/reset

OP-1
#1

Hey all,

Surprise, surprise, another MIDI sync question!

Preamble: I’m working on a patch on my Axoloti (which I’m using as an USB host) that is receiving the MIDI clock and converting it into a pulse/sync signal that can then be sent to PO’s, Modular, etc. In effect, the idea is to send out a traditional style sync pulse, but WITHOUT losing stereo imaging, which is what happens when you send the sync pulse directly from the OP1’s outputs. I essentially want to retain all of my stereo vibes from the OP1, but still be able to sync non-MIDI device like pocket operators.

I’m coming across two problems, and I’m not quite sure if they’re related:

  1. OP1 constantly sends MIDI clock, and this doesn’t seem to be connect to start/stop on the tape. This means that regardless of whether the tape is running, anything connected via the sync will free-run (albeit in time with the MIDI clock). Anybody know a fix for this, or if there is some MIDI message from the OP1 that can be used to start/stop the clock?
  2. Reading some other threads, it seems that OP1 does not send proper “start” messages, only “continue” (unless triggered from the very start of the tape). Can anyone confirm is FW 225 has fixed this?

Any help mucho appreciato’ed!

#2
  1. That’s the nature of midi clock, it always running, there’s nothing that can be done about that I’m afraid
  2. From what I can tell it sends out a start message anytime the tape is stopped then started again, It doesn’t need to be the start of the tape(i thought it always did this but maybe only since the newest os?)
#3

op1 sends start, continue, and stop, separately from midi clock. if you use the op1 as transport, keep track of that state in your patch. this is not “fixed”, simply it’s how it works afaik.

#4

not familiar w/ exactly how axo works

but possibly a way around this is to use the axo to filter/control the transmission of the sync/pulse.
so the axo is always receiving but only starts sending out when it receives a start/continue and stops when it receives stop…something like that.