The last t ime I configured an USB connected sound card was in openSUSE 13.1. I did then same as in earlier openSUSE releases. I do not knnow if that has changes. Also, because that is some time ago I am not sure of all the details.
YaST > Hardware > Sound.
Then the Add buton. On the new screen the left column has Generic. Then the right column has only one item USB Audio. Etc.
IMHO you can then use the device in tools and programs.