I have been playing decent audio from my HP Pc onboard audio (Beats) via the line out to the aux in on my Sony STR-DE898 receiver. I thought I would crank it up a notch and install a Sound Blaster Z and use an optical cable. My problem is that there is no line out on the sound blaster. I tried using the line out L/R to the aux in but the sound seems muddled. I tried the optical cable to the MD Tape in but it only plays through the two front speakers.