No jack server

[hapibeli]

Wed Sep 9 10:05:00 2020: Starting jack server...
Wed Sep 9 10:05:00 2020: JACK server starting in realtime mode with priority 10
Wed Sep 9 10:05:00 2020: self-connect-mode is "Don't restrict self connect requests"
Wed Sep 9 10:05:00 2020: ERROR: control open "hw:USB" (No such device)
Wed Sep 9 10:05:00 2020: ERROR: control open "hw:USB" (No such device)
Wed Sep 9 10:05:00 2020: creating alsa driver ... hw:USB|hw:USB|1024|2|44100|4|4|hwmon|hwmeter|-|32bit
Wed Sep 9 10:05:00 2020: ERROR: control open "hw:USB" (No such device)
Wed Sep 9 10:05:00 2020: ERROR: ALSA: Cannot open PCM device alsa_pcm for playback. Falling back to capture-only mode
Wed Sep 9 10:05:00 2020: ERROR: control open "hw:USB" (No such device)
Wed Sep 9 10:05:00 2020: ERROR: control open "hw:USB" (No such device)
Wed Sep 9 10:05:00 2020: ERROR: Cannot initialize driver
Wed Sep 9 10:05:00 2020: ERROR: JackServer::Open failed with -1
Wed Sep 9 10:05:00 2020: ERROR: Failed to open server
Wed Sep 9 10:05:01 2020: Saving settings to "/home/dirk/.config/jack/conf.xml" ...
10:05:02.914 Could not connect to JACK server as client. - Overall operation failed. - Unable to connect to server. Please check the messages window for more info.
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock

[Bings]

Try this https://ubuntustudio.org/ubuntu-studio-installer/ It's a nice tool for adding lots of functionality in one go. I have jack server working fine with it.