Please pardon me, but what exactly does a DAC do? My system as it stands consist of an old (ca 1972) amp, Thorens TD125+SME 3009+Shure V15 II, TEAC cassette deck, speakers and headphone. Planned upgrades could possibly include replacement of the amp by a more modern unit and I might add an FM tuner later. As I understand it, I do not need a DAC. But what if I should add a CD player/transport? And what is the difference between CD transport unit and a CD player?