Zynthian set-up using Steinberg UR22 mkII


After following the forum for a while I decided to try Zynthian for myself using some hardware I have laying around: a Pi 3 b+, WaveShare 10.1" IPS touchscreen and a Steinberg UR22 mkII USB audio and midi interface.

I have the screen working correctly, I set the wiring layout to DUMMIES, and the soundcard to USB audio, but I keep getting an error screen. When I checked aplay -l the UR22 is listed correctly. When I try running the /zynthian/zynthian-sys/sbin/zynthian.sh script, it gets into an eternal loop full of errors:

The first error seems to be the line ‘ALSA lib pcm_hw.c:1667: (_snd_pcm_hw_open) Invalid value for card’. Does this mean that I have to change something in the audio configuration, or could there be another problem?


Jack would seem to be at the root of the problems…

the output of aplay -l & aplay -L would see what is being seen from the alsa end.

Try firing up qjackctl via the Putty terminal and see how far it gets.


Thanks for your help!

qjackctl returns the error ‘qjackctl: cannot connect to X server’


You want to select the Putty/Connection/SSH/X11 Enable X11 forwarding…

This will allow the Xwindow server to run on your desktop and see the qjackctl interface window…


Ok, I got X11 forwarding working (for which I also had to install Xming) and now I’m in the connections window, but both the audio and midi tabs are empty and the ALSA tab only shows the UR22 midi ports:


How to find out why Jack doesn’t recognise the audio ports?


Sorry I haden’t thought you might be on windows.

Presumably qjackctl reports not started?

Does the USB port exist as alsa devices? (output of aplay -l)


Unless I understand the output wrongly, it seems to me that it exists:


Ok try playing audio via the mpg123 command line command…

> cd /zynthian/zynthian-data/audio/
> mpg123 test.mp3

You should hear the test audio file . . . .

Card 1 ( I suspect that should be card 0) ?

Don’t know if this stuff is relevant or a bit of a wild goose chase . . .

Sadly I’ve not used USB…


Playing audio via mpg123 doesn’t work:

Do I understand it correctly that it is trying to play over Jack?

I think I’ll have to do some reading on ALSA and Jack to understand what is going on - I don’t have too much Linux experience…


Yes it’s involved.

Alsa handles the physical ports and provides a virtual framework with software audio handling and a good deal else as well. Jack handles the movement of data between the ports and provides a low latency environment that is designed for ‘professional’ (whatever that means) but they are different beasts. There are programmes for moving between the two different worlds like a2jmidi and a2j.
By in large USB does seem to just work, but you will need to turn off all the jack components to get the alsa stuff to play a sound file.You need to be able to see the device you are using in the jack world, I don’t know how this works for your specific USB device, but if we can get it playing files under Alsa we ‘should’ be able to get it to do something useful.


As you noted before, the problem seems to be related to the card number set to 1 instead of 0, because that is exactly the error speaker-test returns:

Continuing my investigation…


I managed to get a sound by calling speaker-test with option -Dplug:hw:1

By the way: I’m also only able to start alsamixer with the option -Dhw:1

Since there aplay -l doesn’t list any card number 0, only 1, which is the UR22mkII, I changed hw:0 into hw:1 in the Jackd options (web configuration), however, if I start up the RB Pi, it now most of the time gets stuck showing this (and after a minute or so the the error screen appears, which every now and then turns black and appears again):

Or sometimes it gets stuck in the following loop (during which the web configuration works normally):

If i run /zynthian/zynthian-sys/sbin/zynthian.sh the error messages are exactly the same as before, meaning that it is still trying to open hw:0. How to force it to open hw:1 instead?


As you say you should be able to alter the Audio conf in the webconf interface (zynthian.local by default). Here you can supply specific start up options for the jack daemon.

You will need to turn on Advanced to see the option…

jackd options

Anyone elese got any ideas …? :smiley: