Stuck/Hanging Notes

Using Zynthian
1

Hi
I am currently going through the tutorial of my Midibox Sequencer and noticed there are constant stuck notes which I can only clear via the Panic button.
It is a simple 3 track setup with a basic bass/lead/drum track.
When I solo each track on the Midibox they each play fine.
All 3 together causes stuck/hanging notes right away.
I have many Zynths but the two newest Zynthian Mini Pi5 have Oram staging and vangelis updated today and both have that problem. I have an older Pi4 Zynth which works fine but is way way before Oram.
The Midibox does send Midi Clock, could this be the issue?
Because when I record the Midi with the Midi recorder I hear the hanging notes during the recording, but when I play it back it is clean again.

2

Hi @HansDampf !

  • Are you using the DIN-5 connector? Could you try with USB?
  • Could you check if the note-offs are received from the webconf’s MIDI log?
  • Could you try disabling the MIDI clock?

Thanks

3

If I understand you correctly: I think I had the same issue once when I tried Native Instruments Super8 Synthesizer with one of my Midi controllers (I think it was Launchpad X). I learned that some controllers send note-off (0x80) messages and others are sending note-on (0x90) messages with velocity “0” on note end. Most instruments might understand both, but in my case it wasn’t the case for Super8.

This might be related here, but I don’t know. Just as possible additional context.

Edit: Probably this is also connected? Strange sustain behaviour in Zynthian?

4

Hi
yes this was oldschool DIN5.
Had to hunt down an usb cable to test.
No issues with the usb cable.
I did not find an option to turn off the midi clock in the Midibox.

What is wrong with DIN5 midi?
I assume if it works with usb there is no issue with note-off or should I check this?

5

I’m starting to suspect that the MIDI overlay for the Pi5 is not working totally fine. We never had this problems with the Pi4. The zynthian MIDI circuit has not changed, but the Pi5 clock subsystem has changed a lot and a timing issue could cause this kind of behavior. I would like to test the real working frequency in the DIN5 MIDI ports with the Pi5. Could somebody measure this? You simply generate some traffic in the DIN-5 MIDI out and measure the frequency with an oscilloscope.

I will try to do it in the next days, but perhaps somebody could do it before :wink:

Regards,

1 Like
6

This is valid beahviour and has been part of the MIDI specification since 1.0 (mid 1980’s) so all instruments should support it. The purpose of the is to allow running status to be used. This is where the command byte is not sent for messages with the same status byte, thinning MIDI traffic by approx.1/3. By sending NOTE-ON messages only for both note-on and note-off you can use running status for both which was a significant boon on DIN-5 MIDI at 31250 baud.

3 Likes
7

Hi jofemodo
unfortunately I do not have an oscilloscope at hand, but I can confirm your suspicion that it is Pi5 related. I did update my older Zynth with a Pi4 to the latest Oram stable branch and did not have any issues with DIN5 midi there.

8

I made a couple of tests and I hope this will shed some light as to what is going on.
I put a pc between the zynth and did record the midi there with reaper, as well as on then pi5 zynth. So both recordings should be the same, but they are not. In addition to that I also captured the Midi log.
The midi hangs are not as bad as directly connected but still there and happen instantly. Channel 3 seems to be the worst.
There is also something wrong with the midi recorder because channel 3 does not play afterwards, it does play during recording. I believe channel 3 and 1 got swapped, on the zynthian recording.
2025-03-06_08_56_34_last_state.001.mid (2.3 KB)
pi5_midi_through_pc_real_t1.mid (2.5 KB)
pi5_midi_through_pc_real.log (32.3 KB)
014-tut3.zss (8.0 KB)

9

FWIW I had a stuck note yesterday when I was playing the Zynthian from a USB controller while I programmed sounds. Just one in a whole afternoon, though.

zyncoder: oram-2502.1 (092fb26)
zynthian-ui: oram-2502.1 (e48c01b)
zynthian-sys: oram-2502.1 (a0a0ac5)
zynthian-data: oram-2502.1 (10f663b)
zynthian-webconf: oram-2502.1 (9e5e062)