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First-rate CD player built for no-compromise sound. Independent processor
section features revolutionary MDS (Multiple Delta Sigma) converter with
24-bit ultra high precision. Full array of coaxial and optical inputs and outputs.
Digital control of CD transport mechanism allows instantaneous optimizing
of servo operation. Noise-free analog output with totally balanced
configuration.
The DP-55V is a further refined version of the
model DP-55 coveted by audio connoisseurs
the world over. It incorporates the latest
advances in digital technology, allowing it to
deliver superb Compact Disc sound.
Independent use of the digital processor is also
possible, providing excellent cost-performance
ratio.
The processor features a revolutionar y MDS
(Multiple Delta Sigma) converter with superb 24-
bit precision. This ensures ultra low distortion
and outstanding signal-to-noise ratio. A set of
digital inputs (coaxial and optical) lets exter nal
digital sources also gain access to this superb
D/A converter, for
playback with opti-
mum sound qual-
ity. The DP-55V
even provides digi-
tal outputs (coaxial
and optical), allow-
ing connection of
digital recorders
such as CD-R,
DAT or MD units.
This lets you make
direct digital recordings of supreme quality, us-
ing the signal from the internal CD transport or
from an external source.
The CD transport section uses fully digital
circuitry for control of all actuators and
mechanical functions. This enables instant
optimization of servo parameters for each
individual disc as it is being played, resulting in
stable operation and a drastic reduction of
readout errors. The laser pickup is an ultra-
compact type with integrated RF amplifier, and
all actuators are driven by balanced circuits
where no current flows in the ground line. A tray
lock feature firmly secures the tray during
playback, and the entire CD mechanism is
mounted on a metal chassis of high rigidity,
designed to minimize any vibrations that may
arise during playback. In this way, the DP-55V
covers every electrical as well as mechanical
aspect to assure highly precise readout of the
digital signal. A digital level control and balanced
output circuitry are fur ther advantages for
optimum sound.
Digital Processor Section
Innovative MDS (Multiple Delta Sigma)
converter reduces distortion to theoretical
limits and assures outstanding S/N ratio
The D/A converter which generates the output
signal is a newly developed type that provides
excellent performance in terms of performance
and sound quality. The
MDS (Multiple Delta
Sigma) principle em-
ploys several delta
sigma type converters
in a parallel configura-
tion which results in adrastic precision enhancement. The delta sigma
principle combines oversampling with noise-
shaping (a kind of digital feedback) which
projects the amplitude information of the digital
signal onto a time axis for precise conversion.
Figure 1 shows several delta sigma converters
which are fed with the same signal and whose
outputs are combined to arrive at the overall
waveform.
In the DP-55V, two delta sigma converters are
operated in parallel, which results in a
performance improvement by a factor of 1.4
(=-ˆš2). An important characteristic of the MDS
principle is that the performance benefits are
achieved regardless of signal frequency and
signal level. Therefore noise at very low signal
levels that was difficult to contain with
conventional delta sigma converters is now
drastically reduced. The audible result is music
reproduction emerging from utter silence with
an impressive sense of clarity and nuance.
Separate processor section with coaxial and
optical input for digital signals
Digital inputs allow the user to enjoy the top-
level performance of the
processor section also
with other components
that can supply a digital
signal, such as another
CD transport or a DAT or
MD player. For utmost
flexibility, the input can
handle both optical and coaxial connections.
Inter nal processing of audio data is carried out
entirely in 24-bit format.
Two digital outputs allow direct digital
recording
The DP-55V provides a coaxial and an optical
output connector which allows direct connec-
tion to the Digital Pream-
plifier DC-330, or to a
digital recorder such as
a DAT, MD, or CD-R unit.
The outputs carry not
only the signal from the
internal CD transport, but
also from components
connected to the digital
input, allowing direct digital recording with un-
precedented flexibility.
Jitter-free high-performance digital
demodulator
Demodulation of the digital signal is carried out
by a CS8412 chip (made by Cr ystal
Semiconductor). This device not only has
extremely low inherent jitter, it also is capable
of absorbing any jitter components contained
the input signal. Since the chip can handle digital
signals up to a width of 24 bits, the advantages
of the MDS principle can be realized with any
type of program source.
Linear phase analog filters provide superior
phase characteristics
The frequency upper range of the D/A converter
output signal by principle contains noise
components. The analog filter serves to remove
such aliasing noise. The filter in the DP-55V is a
3-pole linear phase type filter with outstanding
phase characteristics. The cutoff frequency is
designed to minimize phase shift within the
passband. Strict selection of all filter components
assures sonic purity and total musical accuracy.
Digital level control prevents sound quality
deterioration
The 24-bit MDS D/A converter in the DP-55V
has an 8-bit margin, which allows precise level
attenuation down to -40 dB without any loss in
signal quality.
Fully balanced analog output circuitry
The audio output section features completely
balanced circuitr y which is isolated from the
ground line. Any noise that may be induced in
Optical input display example
Optical input display example
Fig. 1 MDS type D/A converter principle
Linearity (digital input vs. analog output)
Digital
inputSignal
Conversion error
MDS
output
Note the ratio between signal and
conversion error. In the MDS output,
the error is very small in relation to
the signal.
Digital input Analog output
LINEARITY
Digital outputs
Digital inputs
[dB]
[dB]
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CD transport control assembly
Comprises the CD transport servo control/key input/
display/output level microcontroller, balanced
actuator drive circuit and other components.
Digital I/O, D/A converter assembly
Comprises the coaxial/optical digital
input/output connectors, PLL circuitry,
digital filter, MDS type D/A converter and
other components.Analog output assembly
Comprises the 3-pole analog filter, balanced/
unbalanced audio output circuitry, power supply
circuits, unbalanced output jacks, balanced output
connectors and other components.
the signal path will be canceled out, so that the
playback sound remains utterly pure and
undiluted. For utmost flexibility, balanced XLR
connectors as well as unbalanced RCA-type
connectors are provided.
CD Transport Section
Fully digital control of CD mechanism
The control circuitry of the mechanism section
is fully digital, allowing the use of adaptive filtersto optimize servo performance for each
individual disc. This assures enhanced
operation stability and a drastic reduction in error
rate.
Laser pickup with integrated RF amplifier for
error-free operation
Since the output level of a laser pickup is very
low, it is highly vulnerable to externally induced
noise. To prevent such problems, the pickup
used in the DP-55V employs an RF amplifier
which is so compact that it can be directly
Remote commander RC-18
Allows operation of all functions except power
on/off. Enjoy superb convenience by switching
input sources or controlling features such as
direct play, program play and repeat play.
integrated in the pickup assembly. This assures
that the high-level output signal remains free
from noise interference, which in turn reduces
the error rate.
Analog output with balanced circuitry
