Gijsbert, zie hier......
SB Audigy 1 [SB0092], ADC Capture/Standard PCM Playback
IEC958 (S/PDIF) Digital Audio Output
front:CARD=default,DEV=0
RockFrog , USB Audio
Front speakers
surround40:CARD=default,DEV=0
RockFrog , USB Audio
4.0 Surround output to Front and Rear speakers
surround41:CARD=default,DEV=0
RockFrog , USB Audio
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=default,DEV=0
RockFrog , USB Audio
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=default,DEV=0
RockFrog , USB Audio
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=default,DEV=0
RockFrog , USB Audio
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=default,DEV=0
RockFrog , USB Audio
IEC958 (S/PDIF) Digital Audio Output
ubuntu@ubuntu-desktop:~$