http://voices.canonical.com/david.henningsson/2014/03/07/headset-jacks-on-newer-laptops/
you are using old version of alsa driver since alc668 has been rename to alc3661
http://bazaar.launchpad.net/~unity-settings-daemon-team/unity-settings-daemon/trunk/view/head:/plugins/media-keys/what-did-you-plug-in/pa-backend.c
http:// voices. canonical. com/david. henningsson/ 2014/03/ 07/headset- jacks-on- newer-laptops/
you are using old version of alsa driver since alc668 has been rename to alc3661
http:// bazaar. launchpad. net/~unity- settings- daemon- team/unity- settings- daemon/ trunk/view/ head:/plugins/ media-keys/ what-did- you-plug- in/pa-backend. c