NEC CD-903

Commentary

A CD player that pursues musicality with carefully selected materials and luxurious circuit design.

The D/A converter employs a 4-channel independent D/A converter that completely separates the right and left channels and the four channels of positive and negative phases. This realizes a perfectly balanced transmission and eliminates the ambiguity associated with phase. In addition, even after analog conversion, 4-channel independent circuits are employed to prevent mutual interference.

It is equipped with error correction, EFM decoder and microcomputer for control newly developed by making full use of NEC technology to improve accuracy and reliability of signal processing.
As for digital filters, we have reduced phase shift and distortion by polishing our original ND filter.

Optical transmission of digital signals is achieved by four optical cables, two for serial data, one for clock signal and one for latch pulse, and five photocouplers for control signal.
As a result, the electronic coupling between the digital circuit and the analog circuit is cut off and the mixing of digital noise is prevented.

Equipped with a low distortion rate analog attenuator that can control 0 to 29 dB in 1 dB steps.
It consists of a high-reliability and high-sound quality resistor and a sealed relay with gold-plated crossbar contacts.

A 3.2 mm thick steel plate is used for the bottom plate to absorb microvibration from the internal rotation system.
In addition, by making the legs of sintered alloy with high rigidity and excellent vibration resistance adhere to the floor surface, the structure is strong against long-period vibration and external vibration.
In addition, 1.6 mm thick steel plate is used for the chassis itself, and 5 mm thick aluminum plate is used for the side plate, top plate and front surface.

The output jacks are equipped with balanced input jacks and two types of unbalanced output jacks (positive and negative).

Equipped with a full-function wireless remote commander.

Model Rating

Type	CD Player
Pickup system	GaAlAs double-heterodyne semiconductor laser
Number of revolutions	Approximately 500 ~ 200 rpm (CLV)
Playing speed	1.2m/s ~ 1.4m/s (constant)
Error correction method	CIRC double error correction method
Number of channels	2 Channel
Compound	16-bit straight line
Frequency characteristic	5 Hz to 20 kHz ± 3 db
Signal-to-noise ratio	102 dB or more
Dynamic range	96 dB or more
Total harmonic distortion factor	Not more than 0.003%
Channel separation	95 dB or more
Wow and flutter	Measurement limit value or less (crystal oscillation accuracy)
Maximum output level	3.0Vrms
Headphone output level	45 mW (200 Ω)
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	38W
External dimensions	Width 430x Height 142x Depth 446 mm
Weight	21kg
Attachment	Wireless Remote Commander