Hi. I am brand new to all of this. My old stereo system components have all recently given out. So far, I have purchased two Polk M50 floor speakers. Mind you, I only listen to music on this system and don't want to spent a fortune. Unfortunately, my husband is a cheapee and bought a Kenwood receiver VR-705 with 5.1 channels. I am going to buy a subwoofer and have a Koss (don't laugh--it was free) CD changer. With what I now own, plus my Polk subwoofer which is on it's way), does it matter what CD changer I have? Will it really affect the quality of music? Also, do I need a digital or optical cable? Please bear with me--I am learning. Thanks for any input.