I've been using an old pioneer receiver (vsx-90txv) as a stereo amplifier for two sets of speakers and a sub woofer. I came by a set of surround speakers at a thrift store and am wondering how to work them into my setup. I've been using a 3.5mm to RCA cable to connect my PC to the receiver but since that only sends a stereo signal my receiver isn't outputting audio on the surround channel. I'm not super into surround sound for movies but I'd like to add these speakers as sort of secondary left and right channels in stereo to help fill out my room more. I've tried using audio through HDMI but this is a bedroom setup and I have a monitor that I'd like to keep using my display port cable with, so my next option is toslink fiber optic I figure. The big question I have is whether or not I can send a stereo source signal through a toslink connection and have it output on my surround channels on my receiver? Or will I be forced into buying a separate amplifier for my other speakers?