sound is handled in slightly different ways on each board.
To handle the grabber boards correctly, there is a array tvcards[] in
-bttv-cards.c, which holds the informations required for each board.
+bttv-cards.c, which holds the information required for each board.
Sound will work only, if the correct entry is used (for video it often
makes no difference). The bttv driver prints a line to the kernel
log, telling which card type is used. Like this one: