Here is the pavucontrol configuration tab:
OK ........ two comments .......
if you are not using the HDMI connection on the PC then it would be advisable to disable (off) the HDMI entry in the Config Tab.
this prevents any apps from using it in error.
when required it is simply a matter of turning it on again.
The built-in audio entry is set to output sounds ONLY.
If you wish to use a microphone plugged into this sound card, then you need the Duplex entry from the drop down for that card.
For your general info and not related to your problem here ...... there are a number of different facilities available when using PA .....
such as sound over LAN, sending sound to all connected devices, multicasting etc ..... made available through PAPrefs.
In addition you can set up a loopback mixer, to mix sounds from various sound sources and output them as one ...... fancy recording a bit of Karaoke?
There is an Equaliser available ... it must have more steps than I have seen on any such application
You can also record to file using the functions of PA, while allowing you to choose any source to record ..... either MIC or a monitor of any of the sound sinks. That includes the mixed output from the loopback mixer.
The veromix plasma widget (in repo) provides a nice interface to manage the PA sounds.
It is a different type of interface to PA Vol Control, while having many of the same functions.
Glad to have helped a little, and go have fun with this stuff