Strange MIDI IN behaviour with a V3 (missing most MIDI events)

Hi everybody,
I have assembled a V3 bundle kit and I am facing a strange problem. Everything seems to work fine except the MIDI IN
I connected a Yamaha keyboard to the MIDI IN and when I play a note, the Zynthian plays it, then it stops working for a few seconds. Even the Note Off event is ignored !
If I continue to play regularly, then after 3 or 4 seconds, a new note is played but none of the notes between. The MIDI IN LED blinks as expected for each MIDI event, not only for those being recognized by the Zynthian.
If I connect a USB MIDI interface, the Zynthian works like a charm and plays all notes, so I assume thats something is wrong in the MIDI IN circuitery.

Another problem is that the MIDI THRU does not blink at all when I play anything on MIDI IN, which is not normal too.

I noticed there are two jumpers (JP1 and JP2) on the Zynaptiq board, but I have no idea if they must be closed or opened. I tried to find the Zynaptiq V3 schematics on the Github (zynthian/hw repository), but I can only find previous version schematics, not the V3 one. Where are the schematics located? With them, I will be able to check the MIDI signal quality with my scope.

Thank you for the help !


Tadaaa !!! I think I found the origin of the problem :smile:

It seems that the Zynthian does not like MIDI coming from my Yamaha CS1x used as a master keyboard. I repeated the test with a Korg DSS1, a Kawai K1, a Technics AX7 and a Korg DW8000 : they all control the Zynthian correctly (blue MIDI indicator on the touchscreen blinks as expected)
But when I connect my CS1x or my DJX as master keyboard (both from Yamaha…) : the Zynthian behaves erratically as described in my first message. So apparently, there is something special in Yamaha MIDI message that the Zynthian does not like.

I will perform further tests and log the MIDI messages sent from the Yamaha machines and compare them with what the other keyboards are doing. There is quite probably a small difference that the Zynthian does not like.


ttyMIDI doesn’t support running status. MIDI in missing note off events I use a cheap midi to usb adaptor for mine instead.

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Hey Baggypants,

I was thinking of something like that (either Running Status or Active Sensing). But I have another Yamaha machine here (a QY700) that uses Running Status and it works with the Zynthian.
I will continue the investigation to be sure we have a complete picture (maybe it could be nice to have the Running Status implemented, as many machines use it)
Now, I have to say that my Zynthian will be driven over RTP-MIDI through a KissBox CM-MIDI2 (KissBox RTP-MIDI does not use the Running Status mechanism, it recreates the complete MIDI message each time, so I am sure there will be no impact)


I’ve opened an issue on github. I’ll share the code I’ll use to dump the messages and then we can both offer a few examples to the dev.