ac3 passthru

ALive!: "The SBLive! is not capable of outputting all its audio in Dolby Digital format (through the S/PDIF output). It is only able to output Dolby Digital and DTS soundtracks that are already pre-encoded and made available on DVDs and other file formats like .AC3 or .VOB. This is because Dolby Digital and DTS are non-PCM formats, unlike the PCM format supported by the EU10K10."