Jack won't start on my RP4

Patchbox OS
1

I have a newly installed version of Patchbox OS on my Raspberry Pi 4. However, I can’t get any sound out of either the AV or the HDMI port. When investigating this matter, by running sudo systemctl status jack.service, I get the following messages, with the word failed showing up in red:

● jack.service - JACK Server
   Loaded: loaded (/lib/systemd/system/jack.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Thu 2021-10-07 13:09:16 BST; 5h 13min ago
  Process: 401 ExecStart=/etc/jackdrc (code=exited, status=255/EXCEPTION)
 Main PID: 401 (code=exited, status=255/EXCEPTION)

Oct 07 13:09:16 patchbox jackdrc[401]: creating alsa driver ... hw:pisound|hw:pisound|128|2|48000|0|0|nomon|swmeter|soft-mode|16bi
Oct 07 13:09:16 patchbox jackdrc[401]: control open "hw:pisound" (No such device)
Oct 07 13:09:16 patchbox jackdrc[401]: ALSA lib pcm_hw.c:1822:(_snd_pcm_hw_open) Invalid value for card
Oct 07 13:09:16 patchbox jackdrc[401]: ALSA lib pcm_hw.c:1822:(_snd_pcm_hw_open) Invalid value for card
Oct 07 13:09:16 patchbox jackdrc[401]: ALSA: Cannot open PCM device alsa_pcm for playback. Falling back to capture-only mode
Oct 07 13:09:16 patchbox jackdrc[401]: Cannot initialize driver
Oct 07 13:09:16 patchbox jackdrc[401]: JackServer::Open failed with -1
Oct 07 13:09:16 patchbox jackdrc[401]: Failed to open server
Oct 07 13:09:16 patchbox systemd[1]: jack.service: Main process exited, code=exited, status=255/EXCEPTION
Oct 07 13:09:16 patchbox systemd[1]: jack.service: Failed with result 'exit-code'.

Even after trying to start Jack, using jack_control start, I still get the same error.

Any ideas?

2

You should reconfigure Jack, run patchbox and enter jack submenu.

3

Thanks for the suggestion. I’ve launched patchbox and tried just about every option possible there. What is it, more specifically, that I’m trying to achieve here?

4

patchbox → jack → config, configure the audio card.

Make sure you use the correct size of audio buffers, based on recommendations on Setup Wizard - Patchbox OS Documentation - if they’re too low, Jack won’t start up.

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