I use a 14,2 27" iMac w Thunderbolt and USB2 plugs. I want to listen to some old cassettes on my computer. There is no LINE-IN on a 14,2 iMac, only a headphones/speaker plug. I already have a portable cassette player, I don't see the point of buying these players to convert to mp3 for $50. Don't all I need is a Stereo to USB cable? As I know nothing about electronics, I want good sound when I convert, or if it is possible. Does anyone ever convert cassettes to mp3 files?