Udev and Pulse

This is about using a USB DAC (digital-analog audio converter) in Sailfish OS. It is an external device that records analog signals via USB, often used in music production and art.

You need to become root:

# devel-su
 #echo 'ATTRS{id}=="mtsndcard", ENV{PULSE_IGNORE}="1"' > /etc/udev/rules.d/89-pulseaudio-usb.rules
 cd /etc/pulse/xpolicy.conf.d
 mv usbaudio.conf.disabled usbaudio.conf
 pactl load-module module-udev-detect

The last command ~~can~~should be ~~persisted~~done ~~with~~at asystem ~~systemd~~boot ~~unit~~through ~~THIS~~pulse. ISSadly ~~NOT~~none ~~finished.~~of the following work:

 edit .config/pulse/default.pa 

.include /etc/pulse/default.pa
load-module module-udev-detect

edit /home/defaultuser/.config/systemd/user/pulse_udev.service

[Unit]
Description=udev-pactl-start-usb-dac

[Service]
Type=oneshot
RemainAfterExit=no
ExecStart=/usr/bin/pactl load-module module-udev-detect

[Install]
WantedBy=multi-user.target

Then run
systemctl --user enable pulse_udev.service

Article discussion: USB DAC playback on Sailfish OS Forum