I had to replace computer motherboard, choice was not so good apparently, because everything works great except sound.
New mobo is Asus P54G1T-ML X with fresh install of 12.04.1 LTS Kubuntu. Sound card: HDA Intel Codec: Realtek ALC887-VD
The sound can be barely heard with the speaker volume turned up to maximum. It is probably issue with the Realtek ALC 887 codec, since there is myriad of problems in linux with that codec in combination with Intel and Nvidia HDA cards.
I have tried following: - change card models in /etc/modprobe.d/alsa-base.conf to: auto, 3-stack, asus etc. as stated in "HD-Audio-Models.txt" with no success (the ALC887 codec is just not listed anywhere) - install of alsa dkms drivers didn't change anything, sound is still very low - removing pulse audio also didn't change anything except that Kmix in that case clearly states for playback device "Intel HDA Realtek ALC 887" card, while with pulse audio it states "Built-in Audio Analog Stereo", sound remains the same - also have tried with some asound.rc configs but it didn't help either - in alsamixer everything is unmuted and turned up
If anyone have some other solution, please reply.