A series of tests:
Test 1:
OP-1: “endless arp” sends notes to Hermod, it is directly connected via “USB host”
Hermod: Sends a clock to the OP-1 but is not the master clock (an Octatrack is, the clock is received on the DIN input). A “Midi out” effect is added to the track, for monitoring the Midi on a computer and to find out if only the gates are dropped or the midi as well. (spoiler: both. That explains the stucked notes on my P12)
Everything’s fine during a couple of seconds or minutes. Here’s the output of Midi Monitor, totally normal:
19:32:15.376 From HST 2 Note Off 1 59 0
19:32:15.377 From HST 2 Note On 1 61 127
19:32:15.439 From HST 2 Note Off 1 61 0
19:32:15.440 From HST 2 Note On 1 64 127
19:32:15.501 From HST 2 Note Off 1 64 0
19:32:15.502 From HST 2 Note On 1 71 127
19:32:15.563 From HST 2 Note Off 1 71 0
19:32:15.564 From HST 2 Note On 1 69 127
19:32:15.626 From HST 2 Note Off 1 69 0
19:32:15.627 From HST 2 Note On 1 64 127
19:32:15.689 From HST 2 Note Off 1 64 0
19:32:15.690 From HST 2 Note On 1 61 127
19:32:15.749 From HST 2 Note Off 1 61 0
And when I notice/hear that some gates are being dropped, here’s the corresponding output of Midi Monitor:
19:32:19.610 From HST 2 Note On 1 56 127
19:32:19.611 From HST 2 Note Off 1 63 0
19:32:19.672 From HST 2 Note On 1 56 127
19:32:19.734 From HST 2 Note On 1 58 127
19:32:19.735 From HST 2 Note Off 1 56 0
19:32:19.795 From HST 2 Note On 1 61 127
19:32:19.796 From HST 2 Note Off 1 58 0
19:32:19.858 From HST 2 Note On 1 68 127
19:32:19.859 From HST 2 Note Off 1 61 0
19:32:19.920 From HST 2 Note Off 1 68 0
19:32:19.921 From HST 2 Note On 1 66 127
19:32:19.983 From HST 2 Note Off 1 66 0
19:32:19.984 From HST 2 Note On 1 61 127
As you can see, a new “note-on” message is sent to 56 instead of a “note-off”, the same for some other notes and everything goes wrong… In fact, the note on is sent twice but only one note off is sent, this causes « stucked notes » on a poly synth like a Prophet.
Test 2 : Same sequence sent directly to my computer and monitored during a few minutes, no overlapping :
19:45:53.034 From OP-1 Midi Device Note On 1 69 127
19:45:53.103 From OP-1 Midi Device Note Off 1 69 64
19:45:53.103 From OP-1 Midi Device Note On 1 67 127
19:45:53.171 From OP-1 Midi Device Note Off 1 67 64
19:45:53.171 From OP-1 Midi Device Note On 1 62 127
19:45:53.239 From OP-1 Midi Device Note Off 1 62 64
19:45:53.239 From OP-1 Midi Device Note On 1 59 127
19:45:53.307 From OP-1 Midi Device Note Off 1 59 64
19:45:53.307 From OP-1 Midi Device Note On 1 71 127
19:45:53.375 From OP-1 Midi Device Note Off 1 71 64
The only difference is that in this scenario, the OP-1 doesn’t receive a midi clock from Hermod (is not in Sync mode) but is the master clock.
Test 3: Now, I’d like to find out if Hermod is responsible for that or if the OP-1 goes crazy and generates a wrong suite of messages when it receives an external clock.
Op-1 in sync mode, Clock from Hermod via Iconnect4, and OP1 notes directly sent to the computer : No issue, no overlapping.
Test 4:
Op-1 in sync mode, Clock from Octatrack via Iconnect4, and OP1 notes directly sent to the computer : No issue, no overlapping. So, the OP1 doesn’t seem to be the cause.
Test 5 :
Same setup as in the first test, OP1 in sync mode connected directly to Hermod but this time Hermod is the Master clock. And the issue happens again, very shortly after the Arp has started.
20:15:52.565 From HST 2 Note On 1 57 127
20:15:52.604 From HST 2 Note On 1 59 127
20:15:52.605 From HST 2 Note Off 1 57 0
20:15:52.646 From HST 2 Note On 1 62 127
20:15:52.647 From HST 2 Note Off 1 59 0
20:15:52.689 From HST 2 Note Off 1 62 0
20:15:52.690 From HST 2 Note On 1 69 127
20:15:52.729 From HST 2 Note On 1 67 127
20:15:52.730 From HST 2 Note Off 1 69 0
20:15:52.771 From HST 2 Note On 1 62 127
Test 6 :
Octatrack is the master clock but the clock is sent to OP1 (in sync mode) via Hermod. Op1 is connected directly to the computer. No issue, no overlapping.
N.B: there’s no midi loop that would cause a double « note-on » message in this setup. The only midi out effect in this setup is only here for monitoring the output of Hermod.
EDIT : I notice that an OP-1 sends a Note-off with a velocity of 64 ! Maybe that’s a cause of the problem, don’t you think ?
2ND EDIT: The issue doesn’t happen when a PRO2 arp is the Midi source. This one sends notes-off with a velocity of 0
Sorry for the long message 