My aim was to have both 5.1 and 2ch PCM stereo output via SPDIF and stereo audio simultaneously output via the 3.5mm line out which is hooked up to my TV. This means I can hear the audio my TV without running it through the amp but also allows me to turn on my amp for full 5.1 or 2ch stereo audio when I'm playing a DVD. This is easily done under XP but Vista is another story.