How do I set a pulseaudio card profile persistently across reboots

Solution 1:

To make default settings for the pulseaudio daemon we can edit /etc/pulse/default.pa (as root) to give a default source or sink in the last section by uncommenting the corresponding lines and give in the name of our output sink and input source:

### Make some devices default
set-default-sink <name_of_sink>
set-default-source <name_of_source>

In case your sound card needs a specific profile we can also add the follwing line:

set-card-profile <cardindex> <profilename>

Please make a backup of this file before editing to be able to restore the default setting.

In case you are unsure what name your sink has you can issue the following command in a terminal to list all sinks presently active:

pacmd list-sinks

To test if the sink is correct we can issue

pacmd set-default-sink <nameofsink>

in a terminal before we change the default.pa. Open Audio Settings to see the effect (but this will not actually change the sink with default settings - see this answer!)