You're probably not making a valid comparison in your example. Rather, compare a $4500. single box CD player with a set of separates that also cost about $4500. together. Afterall, a single box CD player also contains a DAC (built in). In this case, and depending on a lot of variables, the single box player MAY (musically) out perform the two box system just because of probable designed and built in synergy between the transport section and the DAC section. However, I have chosen the 2 box route for the CD player's many features and for DAC flexibility, ie I have 2 CD players and a CD recorder plugged into my DAC.
CD player or Transport and DAC
Wanting good sound but not wanting to throw money away, how much more do I get for a separates source than for a single unit? As an example, scanning the for sales here, a Wadia 860 weighs in at $4,500 and a 27ix / 270 combination at $10,000. Similarly for ML equipment. So how much more do I get for the extra $5,500? Any thoughts and experience and other ways of achieving similar quality?