"
[locusonus@sherkin-streambox ~]$ journalctl | grep error
Aug 22 22:07:42 sherkin-streambox alsactl[227]: alsa-lib main.c:1405:(snd_use_case_mgr_open) error: failed to import hw:0 use case configuration -2
Aug 22 22:07:54 sherkin-streambox audio.sh[317]: alsa-lib main.c:1405:(snd_use_case_mgr_open) error: failed to import hw:1 use case configuration -2
"
The install is a rpi zero, iquadio soundcard, over a huawei 3372 4g dongle. The noise is intermittent, and is much louder at night. At this point, I'm very much out of ideas as to how to handle this, or whether anything can be done. I suspect that there is EMI from the dongle. Annoyingly, I had the set up running for weeks in my backgarden with no issues. The streambox is installed on an island, so maybe the 4g signal is weaker there. Maybe the iqAudio + rPi isn't such a good combination if it results in such noise in the field?