Ok so I just got the logitech z5500 speakers. But i already have headphones that are 5.1 and plug into the 3.5mm jacks on my soundcard....would I be able to use a SPDIF cable to hook my speakers up and keep the headset plugged into the 3.5mmjacks? then all i would have to do is switch the output in windows to switch between the two.....Is the toslink cable gonna give me the 5.1 still for the speakers and isnt the toslink better quality then the 3.5mm jacks?