advice on adding dac to old cd ?

I have the upgrade bug but not lots of cash,so I have been checking out dac's for sale on the different sites. My cd is a single disc JVC from 89 (jvc444).It has always served me well and still works great.I have owned a NAD and a Technics and this one sounds better.Would I be better off buying a current player such as cambridge 4 or adding a used DAC for a similar amount of coin.I did get to hear a rather exspensive Pioneer 6-pack in my system and the bass seemed deeper and smoother but it skipped so i dumped it.I have read a lot about Pioneer's transport being well rated so how much of the sound quality comes from the transport? I am pretty happy with the rest of the system. thanks AR 07 int. amp Tara labs interconcet on cd Energy 5.1 energy esm-2 Philips 212/ v15 IV bi-wire 10 GA no-name speaker wire.