CD5001 Original Special Edition (OSE) CD player is the Marantz inhouse modified version of the CD5001. To dramatically improve the sound quality, we critically look to the circuit concept and to all components, after which it is possible to determine where customization is needed. At the end of this detailed process the power supply lines are enforced and the audio circuitry is tremendously tweaked up. Every change will be proved by a listening session. This custom treatment gives a much more consistent response in entire frequency range. Musicalreproduction is characterized by improved transparency and image, as well as tonal accuracy.