I am trying to connect an analog 5.1 logitech speaker setup to my unibody MBP to produce the highest sound quality. Currently I just have the green plug of the three component cables plugged into the notebook. The quality is OK and in stereo. I know that the unibody supports optical sound, so I wanted to know if there was a 3-to-1 converter I could purchase to make use of the other sound channels? Is it perhaps worth it for me to just upgrade to a high end 2.1 speaker setup? All help is appreciated. Thank you in advance.