no sound zynaddsubfx and JACK wont run

I am trying to run zynaddsubfx.

When I start from the command line, I get this: http://paste.ubuntu.com/1378693/

When I start JACK I get this:

http://paste.ubuntu.com/1378694/

Try reconfiguring the jackd2 package:

sudo dpkg-reconfigure jackd2

And answer 'Yes' to the question if you want to enable realtime priority. After that add yourself to the 'audio' group:

sudo usermod -a -G audio yourusername

And try again.

Regards,

Jeremy

For those that want to run it simply as a hello world without JACK on Ubuntu 20.04:

zynaddsubfx -O alsa

With that I got the sound to work.

With this simple setup, it cannot be running at the same time as other applications that use sound, e.g. VLC and YouTube videos on the browser.

If you use zynaddsubfs from inside LMMS, it can run side by side with other audio applications for some reason. And it allows you create MIDI tunes: How to save a file in zyanaddsubfx This is what most newbs will want to start with.