Audio Database


NEC CD-903
280,000yen(around the 1986 time)

The material selected carefully and the compact disk player which pursued musicality by the extravagant circuit design.

The 4ch independent digital analog converter which carried out the full separation of the four channels of a right-and-left channel and positive negative phase at the digital analog converter, and constituted the circuitry is adopted. This has realized the full balance transmit and the ambiguity related to a phase is eliminated. Moreover, the cross interferencee is prevented because after an analog translation adopts a 4ch independent circuitry.

The error correction and EFM decoder which were newly developed making full use of the technology of NEC, and the microcomputer for a control are carried, and the accuracy and robustness of the signal processing are improved.
Moreover, phase gap and distortion are reduced by applying a polish to original network-description filter also about a digital filter.

A total of 2 clock signal for serial datas and four optical cables of one latch pulse each and the object for control signals have realized the optical transmission of a digital signal by five photocouplers.
This intercepted the electronic join of a digital circuit and an analog circuit, and mixing of the digital noise is prevented.

The low-distortion analog attenuator which can control even 0-29dB at a 1dB step is carried.
It has hi-reliability, a high-quality sound electrical resistor, and composition by sealing scheme relay of a gilding crossbar contact.

The steel plate of 3.2mm thickness is adopted as a sole plate, and the fine oscillation from an internal-rotation system is absorbed.
Furthermore, it has a structure strong also against a long oscillation and visitor oscillation of a periodicity by sticking the sintered alloy foot which was excellent in the vibration-proof dynamic behavior with high rigidity to a floor surface.
Moreover, the steel plate of 1.6mm thickness was used for the chassis itself, and the aluminum board of 5mm thickness is adopted as a side plate, a top plate, and the front.

A balance input terminal and two kinds of imbalanced output-terminals of a right phase and negative phase are carried in the output-terminal.

The full function wireless remote commander is carried.


Rating of a mode
Form Compact disk player
Pickup scheme GaAlAs double heterodyne semiconductor laser
Rotational frequency About 500-200rpm (CLV)
Performance velocity 1.2 m/s - 1.4 m/s (regularity)
Error-correcting system cross-interleaved-Reed-Solomon-code double error-correcting system
The number of channels Two channels
Composite-izing 16-bit linear line
Frequency characteristic 5Hz-20kHz±3dB
SN ratio 102dB or more
Dynamic range 96dB or more
THD 0.003% or less
Channel separation 95dB or more
Wow and flutter Below a limit-of-measurement value (quartz-crystal oscillation precision)
Maximum output level 3.0Vrms
Headphone-output level 45mW (200ohms)
Supply voltage AC100V, 50Hz/60Hz
Power consumption 38W
Dimensions The width 430x height 142x depth of 446mm
Weight 21kg
Adjunct Wireless remote commander