"Digital audio cable"? No, I was talking analog. Without analog, the only way a computer can play audio cds is by ripping them. Which is what mplayer cdda:// would do. So I don't know why you're actively against ripping them.

(sorry I don't know the first thing about "digital audio cables", never used them nor did need to use them)

Either way, you did not say why mplayer cdda:// failed.