as suspected your intel model is AD1981
that means we can try, and hopefully remove distortion with model=thinkpad as hinted above
here is one way to do it
open terminal as a local user, assuming gnome you can try
Applications -> System tools -> terminal
copy and paste all of my code box into your terminal, when terminal is open
use mouse to click on edit and choose paste
sudo echo 'options snd_hda_intel model=thinkpad' > /etc/modprobe.d/sound.conf
reboot and test sound.
2) your speakers may be crappy so lower volume a little as poor speakers do cause distortion
and your volumes are already at max
3) you have beep (pcspeaker) at max, which some people find annoying.
holding backspace in a text editor or terminal should be enough for you to hear it
if it annoys lower its volume in alsamixer please
OR arrow to it in alsamixer and press the m key to mute it
4) I don't know anything about that audio console controller.
Do you use it?
any link on how to use it?