Ah, more replies I see whilst I typed mine

Yes, as I said the 3.5mm jack output will output stereo only, and as said the digital output will output multichannel digital audio - but this is dependant on a) what soundcard software you use, and b) what video player software you use!

For example, a DVD rip or AVI will multichannel audiotrack (such as Dolby Digital 5.1) played in Windows Media Player will not output multichannel audio. But use a player like Media Player Classic, Zoomplayer or VLC, and after configuring it correctly you will be able to pass through multichannel audio from the film to the amp with no loss - the amp then decodes the bitstream and you get your 5.1 Dolby Digital or DTS. This is how mine is set up (although I use optical, the principal and practice is the same)

Oh, and SVHS was a (now defunct) format, not a cable. S-Video is not SVHS. Common misconception