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| NEC CD-810 |
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| 89,800yen(around the 1987 time) |
The compact disk player which carries a 16-bit
digital filter and a twin digital analog converter.
In order to
eliminate a digital noise from an analog circuit, the optical-transmission
scheme is adopted.
By this scheme, the signal from a digital circuit is
changed into light, and it is transmitting to the analog circuit,The separation
and the independency of a digital circuit and an analog circuit are realized
including a L/R serial data by using the optical transmission by a photocoupler
for five lines, such as an emphasis signal, a latch pulse signal, and a clock
signal.
The 16-bit digital filter is adopted as a digital filter, and
the burden of an analog filter is eased.
The twin digital analog
converter which equipped L/R independently is carried in the D-A-conversion
part, and the phase difference which was not avoided is banished by the single
digital-analog-converter scheme.
Noise mixing to an analog system is
prevented by adopting as a power-source part the independent 2 power-source
scheme which separated the digital system and the analog system from the stage
of the power transformer completely.
Moreover, a shunt-regulator power
source is adopted as an analog circuit, and the stability is raised.
The
fine oscillation from an internal-rotation system is absorbed because a chassis
reduces a magnetic distortion by giving a copper plating and also adopts the
steel plate of 2.0mm thickness as a sole plate. Moreover, the sintered alloy
foot (50phi15mm) which was excellent in the vibration-proof dynamic behavior
with high rigidity is stuck to a floor surface, and a long oscillation and
extraneous vibration of a periodicity are supported.
The software of an
opposite phase can be reversed with an absolute phase circuit changing switch.
A magnetic distortion is eliminated by surrounding an analog part with a
steel plate.
The large-sized insulator is adopted as a mounting of a
power transformer.
The 70-micrometer thickness OFC Copper-foil printed
circuit board is adopted as the printed circuit board.
It can change
into a three-position supporting by changing the mounting location of a foot.
The power source only for headphone amplifier is carried.
The
index search / time search function is carried.
A 24 music random
program memory functionality and three kinds of repeat functions are carried.
Wireless remote control with a ten key is attached.
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| Form |
Compact disk player |
| Pickup scheme |
GaAlAs double heterodyne semiconductor laser
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| 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±0.5dB |
| THD |
0.005% or less |
| Dynamic range |
95dB or more |
| SN ratio |
100dB or more |
| Channel separation |
92dB or more (1kHz) |
| Wow and flutter |
Below a limit-of-measurement value
(quartz-crystal oscillation precision) |
| Output voltage |
2.0Vrms |
| Supply voltage |
AC100V, 50Hz/60Hz |
| Power consumption |
23W |
| Dimensions |
The width 430x height 101.5x depth of 335mm
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| Weight |
8.8kg |
| Adjunct |
Wireless remote control AR-810 |
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