I was able to reproduce a few bugs consistently and work out why they happen.
In short, the Super 6 has a problem keeping track of how many note on and note offs it has per voice, and if a note overlaps into an already playing note, the note gets stuck, as it only receives a single note off to its 2 note ons.
Depending on your sequencer/daw of choice, this may or may not be an issue to you.
I noticed Ableton Live prevents this from happening, so I can’t make this happen there (at least I wasn’t able to).
However, Cubase which is my main daw, handles this differently. If you have 2 of the same note overlapping, Cubase will send out corresponding note on/offs for both overlapping notes, but Super 6 only receives one of those note offs.
Setting this up in Cubase is as simple as making a midi track, play 2 of the same note, and drag one note over the other so they overlap. In Live, this will automatically cut the overlap, shortening one of the notes.
Cubase wont, so it’ll have 2 notes that play into each other.
Now if you were to make a really fast arpeggio in cubase, and have note length longer than the step length, you will cause this to happen…and as this will make the number of note ons without a matching note off increase quite rapidly, it’ll eventually cause Super 6 to lose the voices completely, making it unable to play a single note anymore. Neither with its keyboard or by MIDI.
Before I thought the only way out of this was to power cycle, but it seems like this can also be cured by sending it note offs…as many note offs as it takes to correct the issue of the mismatch.
I “fixed” this on my end now, by duplicating note offs, as a way to do housekeeping in the midi signal.
So for any note off that is sent over midi, I add another note off. This fixed both my stuck notes, as well as dead voices.
Cubase isn’t at fault here, as all messages come with a matching note off, but Super 6 doesn’t seem to keep up correctly.
I will fill out a bug report to UDO about this, but I figured I’d also post my findings here in case anyone else has issues here.
Also, it’d be interesting to hear which sequencer people are using if they get this problem.