And finally, we're here!!! Many thanks to Ponce-De-Leon and everyone who took the time to address my issue. I hope this topic can be helpful to others as well.
All it took was adding the line:
options snd-hda-intel model=alc256-asus-aio
at the end of the file:
sudo nano /etc/modprobe.d/alsa-base.conf
Thanks again everyone 
