Ubuntu 11.04 has been released. Since it is still possible to use Ubuntu classic desktop with 11.04 (I’m not sure if I ever get used to using Unity), I have decided to upgrade. Upgrade itself was smooth (as usually). After reboot, everything seemed OK, except for the fact there was no sound capture on the (rear) Microphone. Sound preferences Input tab did not show any Connector (selector) to choose input sink.
My audio device: nVidia Corporation MCP72XE/MCP72P/MCP78U/MCP78S High Definition Audio (rev a1)
It took me several hours to find a solution, which was rather easy.
- install
gamix(Graphical sound mixer for ALSA) - Change InputSource from Line (which seems to become default capture sink) to RearMic, change InputSource1 from FrontMic to Line (not needed)
- save ALSA settings with
sudo alsactl store - update .profile file to load saved ALSA settings with
alsactl restore - There is still no connector in the Sound preferences, but microphone works
To find this simple solution, I have tried to reinstall ALSA, which resulted in complete removal of sound card hardware setting from the system. It took several hours to find this script, which installed ALSA correctly back.
Posted by bubblesway 
it-bubbles 
