> What version of ALSA driver are you using? Have you tried updating ALSA > as the version within CentOS is quite old now (1.0.14rc3). > > Elrepo has an updated ALSA driver package here: > > http://elrepo.org/tiki/kmod-alsa > Thanks for that useful information, but can you tell me exactly how to perform the update? I tried 'yum update *alsa*' as I have the Elrepo repository installed, but it came up with 'No Packages marked for Update'. Do I need to completely remove all the currently installed ALSA packages and then do 'yum install kmod-alsa? Any advice gratefully received, thanks. Andy