Infinity US 4-channel Class A/B Amplifier Design, with 2-channel pre-amp outputs & Digital Signal Processing. $255 each. $319 Save 20%. Add to Cart Warning. How To Connect 5.1 Speakers To Your Computer - AddictiveTips Sep 08, 2008hi i am having one lenovo laptop is having only two out puts. that is one haed phone out. and one microphone out. unfortunately i purchased one creative 5.1 home theatre system is having three cables. then how i connected this home theatre system to my laptop. somebody told me purchase one usb sound card,