m MDS type D/A converter achieves 24-bit linearity and minimizes noisem Two sets of digital inputs and outputs m High-performance digital
demodulator with minimum jitter m 3-pole analog filter with hand-selectedcomponents m Fully digital control of CD mechanism m Balanced actuator
drive circuitry

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 optimizingof servo operation. Noise-free analog output with totally balanced
configuration.
The DP-55V is a further refined version of themodel DP-55 coveted by audio connoisseurs
the world over. It incorporates the latest
advances in digital technology, allowing it todeliver superb Compact Disc sound.
Independent use of the digital processor is also
possible, providing excellent cost-performance
ratio.
The processor features a revolutionary MDS(Multiple Delta Sigma) converter with superb 24bit precision. This ensures ultra low distortionand outstanding signal-to-noise ratio. A set ofdigital inputs (coaxial and optical) lets external
digital sources also gain access to this superb
D/A converter, for
playback with optimum sound quality. The DP-55V
even provides digiOptical input display example
tal outputs (coaxialand optical), allowing connection ofdigital recorders
such as CD-R,
DAT or MD units.
Optical input display example
This lets you makedirect digital recordings of supreme quality, using the signal from the internal CD transport orfrom an external source.
The CD transport section uses fully digital
circuitry for control of all actuators andmechanical functions. This enables instant
optimization of servo parameters for eachindividual disc as it is being played, resulting instable operation and a drastic reduction ofreadout errors. The laser pickup is an ultracompact type with integrated RF amplifier, andall 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 ismounted 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 mechanicalaspect to assure highly precise readout of thedigital signal. A digital level control and balanced
output circuitry are further advantages for
optimum sound.

drastic precision enhancement. The delta sigma
principle combines oversampling with noiseshaping (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

Digital Processor Section

drastically reduced. The audible result is music
reproduction emerging from utter silence with
an impressive sense of clarity and nuance.

Innovative MDS (Multiple Delta Sigma)
converter reduces distortion to theoreticallimits 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 performanceand sound quality. TheMDS (Multiple DeltaSigma) principle employs several delta
sigma type converters
in a parallel configuration which results in aSignal
Conversion errorDigitalinputMDSoutput

Note the ratio between signal andconversion error. In the MDS output,
the error is very small in relation tothe signal.

Fig. 1 MDS type D/A converter principle

outputs are combined to arrive at the overall
waveform.
In the DP-55V, two delta sigma converters areoperated in parallel, which results in a
performance improvement by a factor of 1.4(=√2). An important characteristic of the MDS
principle is that the performance benefits areachieved regardless of signal frequency andsignal level. Therefore noise at very low signal
levels that was difficult to contain withconventional delta sigma converters is now
Analog output[dB]

handle both optical and coaxial connections.
Internal processing of audio data is carried out
entirely in 24-bit format.
Two digital outputs allow direct digitalrecording
The DP-55V provides a coaxial and an optical
output connector which allows direct connection to the Digital Preamplifier DC-330, or to adigital recorder such asa DAT, MD, or CD-R unit.
The outputs carry not
only the signal from theinternal CD transport, butalso from components
Digital outputs
connected to the digital
input, allowing direct digital recording with unprecedented flexibility.
Jitter-free high-performance
demodulator

digitalDemodulation 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 capableof absorbing any jitter components contained
the input signal. Since the chip can handle digital
signals up to a width of 24 bits, the advantagesof the MDS principle can be realized with any
type of program source.

LINEARITY

Linear phase analog filters provide superior
phase characteristics[dB]
Digital inputLinearity (digital input vs. analog output)

Separate processor section with coaxial andoptical input for digital signals
Digital inputs allow the user to enjoy the toplevel performance of theprocessor section alsowith other componentsthat can supply a digital
signal, such as anotherCD transport or a DAT orMD player. For utmost
flexibility, the input canDigital inputs

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 a3-pole linear phase type filter with outstanding
phase characteristics. The cutoff frequency isdesigned to minimize phase shift within thepassband. 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 insignal quality.
Fully balanced analog output circuitry
The audio output section features completely
balanced circuitry which is isolated from theground line. Any noise that may be induced inn CD transport control assemblyComprises the CD transport servo control/key input/
display/output level microcontroller, balanced
actuator drive circuit and other components.

n Analog output assemblyComprises the 3-pole analog filter, balanced/
unbalanced audio output circuitry, power supply
circuits, unbalanced output jacks, balanced output
connectors and other components.

n Digital I/O, D/A converter assemblyComprises the coaxial/optical digital
input/output connectors, PLL circuitry,
digital filter, MDS type D/A converter andother components.

the signal path will be canceled out, so that theplayback sound remains utterly pure andundiluted. For utmost flexibility, balanced XLR
connectors as well as unbalanced RCA-typeconnectors are provided.
to optimize servo performance for eachindividual disc. This assures enhanced
operation stability and a drastic reduction in error
rate.
Analog output with balanced circuitry

Laser pickup with integrated RF amplifier forerror-free operationn Remote commander RC-18
Allows operation of all functions except power
on/off. Enjoy superb convenience by switchinginput sources or controlling features such as
direct play, program play and repeat play.

CD Transport Section
Fully digital control of CD mechanism
The control circuitry of the mechanism section
is fully digital, allowing the use of adaptive filters

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

integrated in the pickup assembly. This assuresthat the high-level output signal remains freefrom noise interference, which in turn reduces
the error rate.

Balanced drive circuitry for CD actuators
The motors and actuators which move the disctray, spindle, sled, and the focussing and tracking
assembly are driven by two amplifiers arranged
in a balanced configuration. Because there isConventional circuit
Current flows in ground line.

Drive current

Drive signal

Load

Drive signal

Drive current

If the disc tray is disengaged from the rotatingassembly while the disc is playing, resonances
can degrade the signal quality. In the DP-55V,
the tray is firmly secured during playback, toeliminate any possibility of harmful resonances.

no circuit flowing in the ground line, theoperation of other circuits in the player
remains entirely unaffected.

LoadTray lock prevents resonances

Power-on play and frame display"Power-on play" means that the DP-55V can start
playback when power is turned on, allowing
automatic playback in conjunction with an audio
timer. For precise location of any spot on a disc,the player can display frame information (1 frame= 1/75 second), and functions such as search andrepeat can be carried out in steps of individualframes.

Balanced drive circuit
No current flows in ground line.

CD actuator drive circuit principlen FRONT PANELGUARANTEED SPECIFICATIONS
Guaranteed specifications are measured according to the EIA standard CP-2402.
Measurement disc: CP-2403

CD Transport
m FormatStandard CD format
Quantization:
16 bitSampling frequency:
44.1 kHzError correction principle: CIRC
Number of channels:
2
Revolution speed:
500 - 200 rpm (constant linear velocity)
Scan velocity:
1.2 - 1.4 m/s, constantm Data read principle

Non-contact optical pickup (semiconductor laser)m Laser type

GaAlAs (double heterodyne diode)

Digital Processor

n REAR PANEL

m Input format

EIAJ CP-1201 compatible
Quantization:
16 - 24 bit, linear
Sampling frequency: 32 kHz, 44.1 kHz, 48 kHz

m Digital input format
and level (EIAJ CP-1201)

Format:OPTICAL:
COAXIAL:

Digital audio interface
Input –27 to –15 dBm
0.5 Vp-p, 75 ohms

m Digital output format
and level (EIAJ CP-1201)

Format:OPTICAL:

Digital audio interface
Input –21 to –15 dBm
Wavelength 660 nm
0.5 Vp-p, 75 ohms

COAXIAL:★

1 CD player/processor selectorbutton
2 Disc tray
3 Disc tray open/close button
4 Power switch
5 Play track display
Processor operation: digital input
display
6 Track/index display
Processor operation: sampling
frequency display
7 Time display
8 Output level indicator
9 Play/pause button
J Track search buttons

K Stop button
L Coaxial digital input
M Toslink optical fiber input
N Coaxial digital output
O Toslink optical fiber output
P Balanced output connectors(analog output)
a: Groundb: Inverted (–)
c: Non-inverted (+)
Q Unbalanced output connectors(analog output)
R AC power input (for suppliedpower cord) ★

m Frequency response

4.0 to 20,000 Hz ±0.3 dB

m D/A converter

MDS type, 24 bit
Digital deemphasism Total harmonic distortion

0.0009% (20 - 20,000 Hz)

m Signal-to-noise ratio

114 dBm Dynamic range

110 dBm Channel separation

105 dBm Output voltage
and impedance

BALANCED:UNBALANCED:

m Output level control

0 to –40 dB in 1-dB steps (digital)m Power requirements

120 V/230 V (Voltage as indicated on rear panel) AC, 50/60 Hz

m Power consumption15 W

m Dimensions

Width 475 mm (18-11/16”)
Height 140 mm (5-1/2”)
Depth 394 mm (15-1/8”)

m Weight

11.8 kg (26 lbs) net
16.8 kg (37 lbs) in shipping carton

2.5 V into 50 ohms, balanced XLR type
2.5 V into 50 ohms, RCA-type phono jackm Supplied Remote Commander RC-18
Remote control principle: infrared pulse
Power requirements:
3 V DC, IEC R6 (size AA) batteries × 2
Dimensions:
55 × 194 × 18 mm
Weight:
100 g (including batteries)

Remarks★ This product is available in versions for 120/230 V AC. Make sure that the voltage shown on the rear panel matches the AC line voltage in your area.
★ The shape of the AC inlet, plug of the supplied power cord, and AC outlet depends on the voltage rating and destination country.
Supplied accessories: • AC power cord
• Audio cable with RCA plugs• Remote commander RC-18

m Specifications and design subject to change without notice for improvements.
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