I am recording with UbuntuStudio, I can not get recording with no dependence of volumen level output, before I was with Debian and remember to record from a direct monitor or something with that idea.
Recording dependent of volume level seems to record after DAC and not digital clean origin
Sorry about my english.
Recording what is playing on the computer is described here: https://manual.audacityteam.org/man/tutorial_recording_computer_playback_on_linux.html
It’s the same on Debian and Ubuntu (I use both).