m MDS++ D/A converter achieves amazingly low distortion and superb
S/N ratio m Jitter-free high-performance digital demodulator m 3-poleanalog filter with outstanding phase characteristics m Two sets ofdigital inputs m Two sets of transport outputs m Fully digital control of
CD mechanism m Balanced drive circuitry for servo motors

A player dedicated to CD playback Fully independenttransport and digital processor sections. MDS ++ type
D/A converter for even better performance. Optical andcoaxial digital inputs and transport outputs provide
added flexibility. Fully digital control of CD mechanism
achieves optimization of servo parameters in real time.
The DP-57 features totally
separate CDtranspor t andDisplay example for optical input
processor sections, allowing
individual use ofeach. The processor employs
Display example for coaxial input
an ultra-precise
24-bit D/A converter using a newly developed
MDS++ converter. This takes the MDS (Multiple Delta Sigma) principle pioneered by
Accuphase to new heights. All electrical characteristics have been further improved, asexemplified by minimal distortion, extremely
low noise, and superb linearity.
The outstanding sound quality and highperformance of the processor section canbe accessed also by external digital

DIGITAL SECTION
Focus Coil&Tracking CoilSpindle
ServoController

Sled Motor& Driver

Focus &Tracking ServoController

Digital Audio
Data Encodern Balanced drive circuitry for servo
motorsThe motors and actuators which movethe disc tray, spindle, sled, and thefocussing and tracking assembly are driven
by two amplifiers arranged in a balanced
configuration. Because there is no circuit flowing
in the ground line, the operation of other circuitsin the player remains entirely unaffected.

ClockGenerator

Disc Clamp
Motor & Driver
MasterControlComputer

DisplayDriver

KeyMatrix

Infrared
Receivern Laser pickup with integrated RF amplifier
The pickup used in the DP-57 employs a miniature RF
amplifier which is so compact that it can be directly
mounted in the photodetector pickup assembly. This
provides a high-level output signal free from noiseinterference, which in turn reduces the error rate.

Tray Motor& DriverSM

From RemoteCommanderdB

Display

Drive signal

DriverOpticalTransmitter

Optical

CoaxialTransmitter

Coaxial

OpticalReceiverOpticalPulse AmpCoaxial

Drive signal

DriverTransport
Outputs
DriverDriverConventional circuit(current flows in ground line)

Digital Audio
Interface
Decoder

DigitalInputs

ANALOG SECTIONMDS++
D/A Conversion
System×2

Unbalanced

Left
AnalogOutputs

3-PoleLinear Phase
Low-Pass Filter

Drive current

Spindle Motor& Driver

EFM Decoder& Error
Corrector

n Fully digital control of CD mechanism
Control of the mechanism section is fully digital,
allowing the use of adaptive circuits to optimize servo
performance for each individual disc. This results in a
drastically reduced error rate and enhanced operation
stability, even when the ambient temperature fluctuates.

LoadRFSignal
Processor

CD Transport Section Features and Functions

Drive current

CD

Optical
Headcomponents, via the optical and coaxial digital inputs. The highconversion accuracy of the D/A converter ensures that any
digital signal will be reproduced with optimum fidelity. The
transport section is also equipped with two outputs (optical andcoaxial). This allows connection of a digital recorder for formats
such as CD-R, DAT, or MD, to record the signal from the CDtransport of the DP-57 in the digital domain.

LoadThe DP-57 was created by further refining
the Accuphase model DP-55V using the verylatest in digital technology. The end productis a player solely dedicated to reproducing
Compact Disc sources with impeccablequality.
Although the number of discs released in
SACD format is increasing, the CD whichboasts a history of over 20 years is still themain source format for music lovers the world
over. The “capability to reproduce existing
CDs with even higher sound quality” was awish often voiced by audiophiles, andAccuphase has responded by fur therstrengthening its lineup of dedicated CDplayers. As a result of intensive andinnovative research, Accuphase helps
listeners rediscover the immense musicalpotential of the CD, by making discs soundas lively and detailed as never before.

Balanced

Balanced drive circuit(no current flows in ground line)

CD actuator drive circuitn Tray lock prevents resonances
If the disc tray which is used to slide the disc into theunit resonates due to vibrations generated in therotating assembly while the disc is playing, signal quality
can be degraded. In the DP-57, the tray is firmly secured
during playback, to eliminate any possibility of harmful
resonances.

Balanced
BufferMDS++
D/A Conversion
System×2

Unbalanced

RightAnalog
Outputs

3-PoleLinear Phase
Low-Pass Filter
BalancedBalanced
Buffer

DP-57 Block Diagramn Power-on play and frame display“Power-on play” means that the DP-57 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), andfunctions such as repeat can be carried out in steps ofindividual frames.

MDS++ D/A converter moves another step ahead
SignalMDS (Multiple Delta Sigma) is arevolutionar y design which employs
several delta sigma type converters in aparallel configuration.

Conversion error

S0 (Signal)

Digitalinpute0(Conversion error)

In the combined output of these multiple
converters, conversion errors cancel eachother out, resulting in a drastic
improvement in all relevant aspects of
converter performance including accuracy,
S/N ratio, dynamic range, linearity, andTHD.
In the DP-57, two delta sigma type
PCM1796 converters (made by TexasInstruments) are dr iven in parallel.
Compared to a single converter, thisresults in an overall perfor mance
improvement by a factor of 1.4 (= √2).

MDS output

n MDS type D/A converter principle
Analog output

I (current) /V (voltage)
converter
Voltage summing(Normal phase output)

As shown in the diagram, the MDS ++used in the DP-57 features an enhanced
current-to-voltage (I/V) conver ter forprocessing the D/A conver ter output
current.
In combination with voltage summing, thisdesign results in even better stability andtop-notch perfor mance. The music
emerges from a totally silent background,with breathtaking detail resolution andaccurate spatial information.

Note the ratio between signal
and conversion error. In theMDS output, the error is verysmall in relation to the signal.

(Reverse phase output)(Normal phase output)

Subtraction

Digital input

Linearity (digital input vs. analog output)(Reverse phase output)

n Block diagram of MDS++ converter in DP-57

n Assembly with CD transport control circuitry, digital inputs, transport outputs,
MDS++ D/A converter, 3-pole analog
filter, balanced/unbalanced analog
output circuitry, power supply, etc.
n Supplied remotecommander RC-18
Offers a host of functions
such as input switching,direct play, program play,
repeat, etc.

DAC output

Digital Processor Section Features and Functionsn Coaxial and opticaltransport output connectors allow direct copy ofdigital signal from transport section.

n MDS++ type D/A converter achieves stunning

performance and sound quality
n Jitter-free high-performance digital demodulator
The demodulator used in the DP-57 for processing
the supplied digital signal produces extremely low jitterand significantly reduces any jitter components that
may be present in the input signal.

n Independent processor section. Coaxial and optical digital input
connectors accept signals with a sampling frequency up to96 kHz and resolution up to 24 bit.

Delta Sigma D/A convertern 3-pole linear phase analog filter with outstandingn “High Carbon” cast ironinsulator feet with superior damping characteristics further enhancesound quality

Digital input
connectors

Transport output
connectors

phase characteristics
The cutoff frequency setting of the analog filter circuitry
is optimized in order to keep phase shift in thepassband to a minimum. Only strictly selectedcomponents are used, resulting in
excellent music playback quality.

NOTES
Digital demodulator ICn Digital level control with 0 dB to– 40 dB adjustment rangen Two sets of balanced andunbalanced analog outputconnectors
Balanced and unbalanced analog output connectors

Proper playback (operation/sound quality) of CCCDs is not assured.
m Copy Control CDs (CCCDs) and other types of discs implementing someform of copyright protection may not play properly on Accuphase CDplayers, because such discs may not conform to existing CD standards.
No assurances are made regarding playback and sound quality when using
such discs.
m For detailed information regarding CCCDs, please contact the discmanufacturer.
Only discs conforming to existing CD standards can be played on thisplayer. Check the label on the disc before attempting to use it in thisplayer.

n Front panel

GUARANTEED SPECIFICATIONS[Guaranteed specifications are measured according to the EIA standard CP-2402.][Measurement disc: CP-2403]

CD Transport
m Format:Standard CD format
Quantization:
Sampling frequency:
Error correction principle:
Number of channels:
Revolution speed:
Scan velocity:n Rear panel

16 bits
44.1 kHzCIRC
2500 - 200 rpm(constant linear velocity)
1.2 - 1.4 m/s, constantm Data read principle

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

GaAlAs (double heterodyne diode)m Transport output level(EIAJ CP-1201)

OPTICAL:

Output –21 to –15 dBm
Wavelength 660 nm
0.5 Vp-p, 75 ohms

COAXIAL:

Digital Processor★

A Disc tray
B Disc tray open/close buttonC CD transport/processor selector button
D Power switch
E Play track indicator
processor operation:
digital input indicator
F Track/index indicator
processor operation:
sampling frequency indicator
G Time indicator
H Output level indicator

I Play/pause button
J Track search buttons
processor operation:
external input selector buttons
K Stop button
L Digital input connectors (coaxial, optical)
M Transport output connectors (coaxial, optical)
N Balanced output connectors (analog)
a Ground b Inverted (–)
c Non-inverted (+)
O Unbalanced output connectors (analog)
P AC power connector★

Remarks★ This product is available in versions for 120/230 V AC. Make sure that the voltage shown on therear panel matches the AC line voltage in your area.
★ The shape of the AC inlet and plug of the supplied power cord depends on the voltage rating
and destination country.

n Supplied accessories:m AC power cordm Audio cable with plugs (1 m)m Remote Commander RC-18

m Input format

EIAJ CP-1201 compatible
Quantization:
16 - 24 bits, linear
Sampling frequency:
32 kHz, 44.1 kHz, 48 kHz,88.2 kHz, 96 kHz

m Digital input level(EIAJ CP-1201)

OPTICAL:
COAXIAL:

Input –27 to –15 dBm
0.5 Vp-p, 75 ohms
Digital deemphasism D/A converter

MDS++ type, 24 bitsm Frequency response

4.0 to 20,000 Hz ±0.3 dB

m Total harmonic distortionMax. 0.001% (20 - 20,000 Hz, 24-bit input)m Signal-to-noise ratio

114 dB or betterm Dynamic range

110 dB or better (24-bit input)

m Channel separation

110 dB or betterm Output voltage andimpedance

BALANCED:UNBALANCED:

m Output level control

0 to – 40 dB in 1-dB steps (digital)

2.5 V into 50 ohms, balanced XLR type
2.5 V into 50 ohms, RCA-type phono jacks

Generalm Power requirements

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

14 W

m Maximum Dimensions

WidthHeightDepthm Mass11.7 kg (25.8 lbs) net
16.0 kg (35.3 lbs) in shipping carton

475.0 mm (19-11/16”)
140.0 mm (5-1/2”)
395.5 mm (15-9/16”)

m Supplied Remote Commander RC-18
Remote control principle:
Infrared pulse
Power requirements:
3 V DC, IEC R6 (size AA) batteries × 2
Dimensions:
55 mm × 194 mm × 18 mm
Weight:
100 g (including batteries)• Specifications and design subject to change without notice for improvements.

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B0505

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