NEC CD-810
¥ 89,800 (around 1987)
Commentary
CD player with 16-bit digital filter and twin D/A converter.
An optical transmission system is used to eliminate digital noise from analog circuits.
In this system, signals from digital circuits are converted into optical signals and transmitted to analog circuits. Optical transmission by photo-couplers is used in the Line 5 of L/R serial data, emphasis signals, latch pulse signals, clock signals, etc., so that digital circuits and analog circuits can be separated and independent.
The digital filter uses a 16-bit digital filter to reduce the load on the analog filter.
The D/A converter is equipped with a twin D/A converter with independent L/R, eliminating the phase difference that could not be avoided with the single D/A converter method.
The power supply section employs an independent two power supply system that completely separates the digital and analog systems from the power transformer stage to prevent noise from entering the analog system.
A shunt regulator power supply is also used for analog circuits to improve stability.
The chassis is copper-plated to reduce magnetic strain, and the base plate is made of 2.0 mm thick steel plate to absorb micro vibration from the internal rotation system. In addition, the sintered alloy legs (50 φ 15 mm) with high rigidity and excellent vibration resistance are attached to the floor surface to cope with long period vibration and external vibration.
Software of opposite phase can be inverted by the absolute phase switch.
Magnetic distortion is eliminated by surrounding the analog part with steel plate.
A large insulator is used to mount the power transformer.
The printed circuit board is a 70 μ m thick OFC copper foil printed circuit board.
It can be changed to 3-point support by changing the mounting position of the leg.
It has a power supply for the headphone amplifier.
Equipped with index search and time search functions.
It is equipped with 24 songs random program memory function and 3 types of repeat function.
Wireless remote control with 10 keys is included.
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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 ± 0.5 dB |
| Total harmonic distortion factor | Not more than 0.005% |
| Dynamic range | 95 dB or more |
| Signal-to-noise ratio | 100 dB or more |
| Channel separation | 92 dB or More (1 kHz) |
| Wow and flutter | Measurement limit value or less (crystal oscillation accuracy) |
| Output level | 2.0Vrms |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption | 23W |
| External dimensions | Width 430x Height 101.5x Depth 335 mm |
| Weight | 8.8kg |
| Attachment | Wireless Remote Control AR-810 |