i recently found a spdif header o my motherboard so i made a redneck cable to connect to it and it works great but i don't know much about how it works... my new receiver (its in my sig) doesn't have rca multichannel inputs so im left with either stereo or digital (didn't even think about that when i bought it) and when im listening to music on my computer it only plays in 2.1. that's how it should be but i enjoy listening in surround sound with pro logic 2 and i cant when its on digital. my receiver automatically switches between digital and analog but my computer doesn't. is there any way that i can set my computer to switch between digital and analog audio out too? or at least a way where there's a button i can click to switch?
ProLogic 2 will work on any 2 channel analog or digital signal.
It's not a question of switching the output from your sound card between analog and digital. Which type it outputs depends only on which output you are using and the settings for the sound card. The receiver can deal with either analog or digital input and as you said it switches automatically.
You simply need to change the decoder on the receiver to PLII. You can do it manually by pressing the surround mode button on the receiver or remote and on some receivers you can set a 'default' decoder for various input types so it will automatically choose PLII when it sees 2 channel PCM as the input type.