It is something like this I expected to see.
What kernel is being used on your install? uname -r
in a terminal to find out.
I wonder if it would be worthwhile installing an additional kernel to test whether that would give better results. I have no info on your sound card (ACL887) .... maybe it needs a newer kernel ..... but don't know.
Before that though ...... do you remember if sound was working from the install media (liveCD) before you installed the OS ... or if you still have it can you check?
$ lsmod | grep -i realtek
snd_hda_codec_realtek 153534 1
snd_hda_codec 75755 3 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel .........
Please try that command to confirm the realtek module is loaded.