Under the new exterior it's progression rather than revolution, with the CD5003 using the same audio circuit and DAC as the outgoing '5001, but there has been some purposeful tinkering around the edges – and the resulting performance is a similarly sedate evolution of the CD5001 sound.
The Marantz feels solid when loading a disc (in this instance, Smog's Dongs of Sevotion), and is quickly ready to play. The sound is broad and substantial, with plenty of low frequency heft allied to impressive bass modulation and drive.
The sound knits together convincinglyVoices in the midrange are detailed and expressive, each gasping intake of breath or punchy plosive revealed faithfully. And up at the top of the frequency range, percussive sounds are just bright and shiny enough. The whole frequency range knits together convincingly.             
The CD5003 has sufficient speed and attack to deal with even the most testing dynamic fluctuations, and the low-volume subtlety to build an atmosphere effectively. The soundstage it describes is spacious and well defined, and the Marantz is decisive enough to keep unruly material under control.
Only an out-and-out dancefloor devotee will find anything to quibble with here: the '5003 is perfectly able to thump along with testing tempos, but while it doesn't have two left feet it's not the most nimble player you ever heard. Judge it, as we do, on a strict performance-per-pound basis, though, and you'll find it very persuasive indeed.

Details:

• plays CDs, CD-Rs & CD-RWs, and MP3 & WMA CDs
• CD Text
• random and repeat play
• Auto Music Scan
• Quick Replay automatically backs up 5-60 seconds then begins replaying
• pitch control
• peak level search
• Audio EX mode eliminates potential noise sources for cleaner sound
• aluminum/fiberglass front panel
• remote
• optical and coaxial digital outputs
• gold-plated stereo RCA output
• headphone jack
• remote control input/output (for use with Marantz receivers and amps with a compatible remote control in/out jack)
• RS-232C port for third-party controllers
• signal-to-noise ratio 110 dB
• Cirrus Logic digital-to-analog converter
• 17-5/16"W x 4-1/8"H x 14-7/8"D
• warranty: 3 years