Let me start by saying that I really like my Sony CA80ES changer. I've had it for a few months and it's really proven itself to be a very solid performer. In fact, it's actually exceeded my expectations for a CDP of it's price and class. That said, let's get to the specs. Sony CDP-CA80ES Frequency Response: 2 - 20,000 Hz, ±0.5 dB Total Harmonic Distortion: 117 dB Dynamic Range: >100 dB Channel Separation: >110 dB Marantz CC4000OSE Frequency Response: 20 Hz - 20 kHz Total Harmonic Distortion: 0.004% (1 kHz) Signal-To-Noise Ratio: >95 dB (1 kHz) Dynamic Range: >90 dB (1 kHz) Channel Separation: >95 dB (1 kHz) Well... Specs wise, the Sony simply trashes the Marantz. It's not even close. But, then again, we don't listen to specs so I spent several days listening to different kinds of music to give myself a better idea of the contrasting audio differences between the two. I used the DACs in each of the players and connected the players to my processor using CatCables SilverCats interconnects. Both players were connected to the processor at the same time, each to it's own set of analog inputs. The reason I did this? Because they both did very well as transports and I couldn't tell a lot of difference between the two. Perhaps the Sony was a little bit cleaner, but that may have just been imagined. Needless to say, they both did well in that respect. Dire Straits: Money For Nothing Both did a rather good job, but I immediately could tell that the Marantz was more "laid back" and softer. It's tone, although pleasant, wasn't as accurate as I'd like and certain guitar sequences seemed to blur together making the composition too muddy. This was quite evident in Sultans of Swing, where Knopfler really shines. The Sony detailed every note in Mark's solo but without being harsh. The 4000OSE, though, didn't fare as well. Winner: Sony CDP-CA80ES Sarah Mclachlan: Mirrorball Now things got interesting. The relaxed atmosphere produced by the Marantz was very nice. One of the best examples of this was in the track "Do What You Have To Do" where the softness of Sarah's vocals achieved an almost dream-like quality through the DACs of the CC4000OSE... "soothing" is the best way to describe the Marantz changer in this instance. The Sony did well also, but it seemed almost too bright in comparison. It articulated well, but it missed out on presentation... accuracy, but at the cost of some "soul". Winner: Marantz CC4000OSE Three Doors Down: The Better Life Here again, the Marantz was too laid-back. The desperation in the vocals for "Duck and Run" was almost completely lost. In contrast, the CA80ES had the targetting of a sharpshooter, nailing the audial nuances and changes time and time again. I really had to fight to keep from singing along. Winner: Sony CDP-CA80ES W.A. Mozart: Requiem Conductor: L. Bernstein By far this was the tightest race. I enjoyed the atmosphere of the Marantz, but was pulled in by the articulation of the Sony. The Sony was never too harsh, and neither was the Marantz ever too warm. Both had their own merits, and although different, were equally involving. Winner: Draw If I had to choose one changer from both of these I'd have to go with the CA80ES, simply because it best plays the music that I listen to the most (alternative, classic rock, etc). Not to mention it's cool CD Text capabilities, which are fully user configurable. But for those times when more softness is required the CC4000OSE is a great change of pace and a fine piece of equipment in it's on right. Both players are solidly built and have quality mechanics, neither hiccuped once during the testing and both are well laid out with their functions easily accessible and ergonomically placed. From a visual standpoint, the nod goes to the Marantz, it's a handsome piece of gear and the blue on the tray really sets it off. Not to say that the Sony is ugly, it's just not as "pretty". From a connection standpoint, both have gold plated RCAs and neither had any problems during testing. Although, here is where I'd give the CC4000OSE a strong endorsement. The Sony only comes with an Optical output while the Marantz is Coaxial... and I and most others prefer Coax simply because of it's durability and lesser expense for interconnects. So, if you plan on using one of these as a transport only, keep this in mind. Not that I've had a problem with Optical, just thought I'd point this out. I know, this ran a bit long. But FWIW, both players did well, with each excelling in one particular area or another. CDPs, like most other audio equipment, are a personal preference and it really depends on what type of music you listen to most. Which am I keeping? Both of them! I like each for diferent reasons and they'll do well in contrast to each other in my audio rack.