Plantronics GameCom 780 digital output/input missing
Under Ubuntu 13.10, the Plantronics GameCom 780 digital output/input is missing.
Fix: Remove/comment out the Plantronics GameCom entry under USB-Audio.
When used as an analogue only device, the volume at 1% is unusably loud, as such as this device can only be used as a digital device. There appears to be no fix for the analogue driver, as it is reportedly a firmware bug, according to a alsa mailing list thread.