
NEC CD-830DS |
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99,800yen(around the 1988 time) |
The compact disk player which carries new
technology, such as newly developed digital servo and an optical pickup with
built-in I/V amplifier.
Newly developed 16 fs Transversal Filtering
Circuit is carried.
In this circuitry, it is adding the signal which delayed
the periodicity 1/2 to the signal of oversampling 8 times,Since the average
interpolation system is constituted and a sampling frequency becomes twice in
false, the hold aperture time was set to one half of 1.4microsec at the time of
8 time oversampling, and has obtained the smoother wave. Moreover, random noise
was set to 1/root2 by addition of the data, and an S/N ratio modification of
about 3dB is realized. Furthermore, the energy interpolated by a low pass filter
becomes half (-6dB), the burden of a low pass filter is eased, and an expansion
of a passband and a modification of phase distortion are possible.
4 DAC
Balanced Summing System is adopted as a D-A-conversion part.
As for this, it
is possible for you to use the digital analog converter of two pieces of Lch and
Rch each, to make each other cancel the inphase noise of the digital analog
converter by the side of + and -, and to make 1/root2 also reduce random noise
simultaneously, and it has realized the S/N ratio modification of 3dB or more
compared with the conventional scheme.
Furthermore, the glitchres digital analog converter was adopted, the sample
hold circuit which newly generates a spike noise and has an ill effect
on a tone quality was cut, and circuitry is made simple.
Full use of the bipolar process of a two-layer product line
was made in the pickup part, and the I/V amplifier built-in optical pickup which
integrated the PIN photodiode of six splitting patterns and six I/V translation
amplifier of a single power-source operation on the same chip is adopted as it
by reduction-izing of a chip, and shading of the IC section.
Thereby, the
output of an optical pickup serves as a voltage transition type, can make an
Output load impedance low, and is reducing the influence by an exogenous noise.
Moreover, the error rate was reduced and the improvement in a tone quality is
also realized.
In order to realize the faithful and optimal servo, the
world's first digital-servo circuitry is developed and carried.
This servo circuitry is by exclusive LSImuPD6353G developed newly,It has
composition which accumulated each digital loop filter of a focal servo
and a tracking servo, a PWM (pulse duration modulation) output circuit,
1 track jump control circuit, the track jump counter, the brake circuitry,
RF signal detection circuitry, and RF comparator on one chip.
It is building in a focal servo and a tracking
servo independently,Since the arbitrary filter factors (gain, a time constant,
etc.) according to a transition of the status of a pickup can be set up with the
microcomputer for a system control,Unlike that to which the filter factor is
being fixed like the conventional analog servo circuitry, the flexible and
faithful servo is realized to a transition of the signal from a disk.
Moreover, the robustness is improved by functional concentration-ization
of IC. Furthermore, the energy loss of the servo driver stage is reduced
because a pickup servo serves as a PWM drive.
The griddle of 2.0mm thickness is adopted as a sole plate, and also the
fine oscillation from an internal-rotation system is absorbed by adoption
of a center chassis. Moreover, it has a structure strong against a visitor
oscillation by sticking the sintered alloy foot (phi66.18mm) which was
excellent in the vibration-proof dynamic behavior with high rigidity to
a floor surface. (A selection of point shorted-to-ground / interview place
is possible)
The digital stage and
the analog stage are completely separated from the power transformer, and noise
mixing to the analog stage is prevented.
It is possible to carry the absolute phase (signal polarity) circuit changing switch, and to put the
polarity of a systemwide and the polarity of the source together.
The
digital (light/coaxial) output is carried.
In order to prevent the ill
effect by a digital signal, the optical-transmission scheme is adopted.
The very-thick OFC code is adopted as a power cord.
Performance
time edit functions, such as a digital fadeout functionality, an auto edit
function and a manual edit function, a disk change edit function, an auto space
functionality, and a music window within residual time, are carried.
Moreover, a deletion special-NetWare-program play, random play, and intro
scan,24 music random program memory, 3 mode repeat function between all songs /
special NetWare program / A-B, a time search, a track search, an index search, 2
speed music search, a power-source on-start functionality, six kinds of time
windows, etc. are possible.
The large-sized-with music calender display
device in which a luminosity is changed to three steps is adopted.
The
headphone jack with a volume is carried.
Wireless remote control is
attached.
|
Form |
Compact disk player |
Frequency characteristic |
5Hz-20kHz±0.5dB |
THD |
0.0025% or less |
Dynamic range |
98dB or more |
S/N ratio |
105dB or more |
Channel separation |
103dB or more |
Wow and flutter |
Below a limit-of-measurement value
(quartz-crystal oscillation precision) |
Output voltage |
2.5Vrms |
Power source |
AC100V, 50Hz/60Hz |
Power consumption |
25W |
Dimensions |
Width 430x height 90x depth of 320mm
Width 430x height 112x depth of 328mm (maxima) |
Weight |
11.5kg |
Adjunct |
Wireless remote control AR-830DS |
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