Accuphase DP-57 Brochure

m MDS++ D/A converter achieves amazingly low distortion and superb

S/N ratio m Jitter-free high-performance digital demodulator m 3-pole
analog filter with outstanding phase characteristics m Two sets of
digital 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 independent

Driver

Driver

Driver

Drive signal

Load

Drive current

Drive current

Load

Drive signal

Conventional circuit

(current flows in ground line)

Balanced drive circuit

(no current flows in ground line)

The DP-57 was created by further refining
the Accuphase model DP-55V using the very
latest in digital technology. The end product
is a player solely dedicated to reproducing
Compact Disc sources with impeccable
quality.
Although the number of discs released in
SACD format is increasing, the CD which
boasts a history of over 20 years is still the
main source format for music lovers the world
over. The “capability to reproduce existing
CDs with even higher sound quality” was a
wish often voiced by audiophiles, and
Accuphase has responded by further
strengthening its lineup of dedicated CD
players. As a result of intensive and
innovative research, Accuphase helps
listeners rediscover the immense musical
potential of the CD, by making discs sound
as lively and detailed as never before.

Focus Coil

&

Tracking Coil

Optical
Head

Spindle Motor

& Driver

Sled Motor

& Driver

CD

Disc Clamp

Motor & Driver

Tray Motor

& Driver

Signal

Processor

Spindle

Servo

Controller

Focus &

Tracking Servo

Controller

Master

Control

Computer

Key

Matrix

transport and digital processor sections. MDS
D/A converter for even better performance. Optical and
coaxial 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 CD
transport and
processor sec-

Display example for optical input

tions, allowing
individual use of
each. The pro­cessor employs
an ultra-precise

Display example for coaxial input

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, as
exemplified by minimal distortion, extremely
low noise, and superb linearity.
The outstanding sound quality and high
performance of the processor section can
be accessed also by external digital

RF

EFM Decoder

& Error

Corrector

Display

Driver

Infrared
Receiver

From Remote
Commander

Clock
Generator

Digital Audio

Data Encoder

Display

DIGITAL SECTION

S

M

dB

components, via the optical and coaxial digital inputs. The high
conversion 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 and
coaxial). This allows connection of a digital recorder for formats
such as CD-R, DAT, or MD, to record the signal from the CD
transport of the DP-57 in the digital domain.

CD Transport Section Features and Functions

nn

n Fully digital control of CD mechanism

nn

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.

nn

n Laser pickup with integrated RF amplifier

nn

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 noise
interference, which in turn reduces the error rate.

nn

n Balanced drive circuitry for servo

nn

motors

The motors and actuators which move
the disc tray, spindle, sled, and the
focussing 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 circuits
in the player remains entirely unaffected.

++ type

Digital Audio

Interface
Decoder

MDS

D/A Conversion

System

MDS

D/A Conversion

System

Optical

Transmitter

Driver

Coaxial

Transmitter

Optical

Receiver

Pulse Amp

++

×

2

3-Pole

Linear Phase

Low-Pass Filter

Balanced

Buffer

++

×

2

3-Pole

Linear Phase

Low-Pass Filter

DP-57 Block Diagram

Balanced

Buffer

Optical

Coaxial

Optical

Coaxial

Unbalanced

Balanced

Unbalanced

Balanced

Transport
Outputs

Digital
Inputs

ANALOG SECTION

Left
Analog
Outputs

Right
Analog
Outputs

CD actuator drive circuit

nn

n Tray lock prevents resonances

nn

If the disc tray which is used to slide the disc into the
unit resonates due to vibrations generated in the
rotating 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.

nn

n Power-on play and frame display

nn

“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), and
functions such as repeat can be carried out in steps of
individual frames.

MDS++ D/A converter moves another step ahead

MDS (Multiple Delta Sigma) is a
revolutionary design which employs
several delta sigma type converters in a
parallel configuration.

In the combined output of these multiple
converters, conversion errors cancel each
other out, resulting in a drastic
improvement in all relevant aspects of
converter performance including accuracy,
S/N ratio, dynamic range, linearity, and
THD.

In the DP-57, two delta sigma type
PCM1796 converters (made by Texas
Instruments) are driven in parallel.
Compared to a single converter, this
results in an overall performance
improvement by a factor of 1.4 (= √2).

As shown in the diagram, the MDS

++

used in the DP-57 features an enhanced
current-to-voltage (I/V) converter for
processing the D/A converter output
current.

In combination with voltage summing, this
design results in even better stability and
top-notch performance. The music
emerges from a totally silent background,
with breathtaking detail resolution and
accurate spatial information.

Analog output

Linearity (digital input vs. analog output)

Digital input

Signal

Conversion error

Digital
input

nn

n MDS type D/A converter principle

nn

I (current) /V (voltage)
converter

(Normal phase output)

(Reverse phase output)

(Normal phase output)

(Reverse phase output)

n n

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

n n

Voltage summing

Note the ratio between signal
and conversion error. In the
MDS output, the error is very
small in relation to the signal.

S

0

(

Signal)

e

0

(Conversion error)

MDS output

Subtraction

DAC output

nn

n Assembly with CD transport control cir-

nn

cuitry, digital inputs, transport outputs,

MDS++ D/A converter, 3-pole analog

filter, balanced/unbalanced analog

output circuitry, power supply, etc.

nn

n Supplied remote

nn

commander RC-18

Offers a host of functions
such as input switching,
direct play, program play,
repeat, etc.

Digital Processor Section Features and Functions

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 jitter
and significantly reduces any jitter components that
may be present in the input signal.

n 3-pole linear phase analog filter with outstanding

phase characteristics

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

n Digital level control with 0 dB to

–40 dB adjustment range

n Two sets of balanced and

unbalanced analog output
connectors

n n

n Front panel

n n

n n

n Rear panel

n n

Balanced and unbalanced analog output connectors

Delta Sigma D/A converter

Digital demodulator IC

nn

n Independent processor section. Coaxial and optical digital input

nn

connectors accept signals with a sampling frequency up to
96 kHz and resolution up to 24 bit.

nn

n Coaxial and optical

nn

transport output connec­tors allow direct copy of
digital signal from trans­port section.

nn

n “High Carbon” cast iron

nn

insulator feet with supe­rior damping character­istics further enhance
sound quality

Digital input

connectors

Transport output

connectors

NOTES

Proper playback (operation/sound quality) of CCCDs is not assured.

m Copy Control CDs (CCCDs) and other types of discs implementing some

form of copyright protection may not play properly on Accuphase CD
players, 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 disc

manufacturer.

Only discs conforming to existing CD standards can be played on this
player. Check the label on the disc before attempting to use it in this
player.

GUARANTEED SPECIFICATIONS

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

CD Transport

m Format: Standard CD format

mm

m Data read principle Non-contact optical pickup (semiconductor laser)

mm
mm

m Laser type GaAlAs (double heterodyne diode)

mm
mm

m Transport output level OPTICAL: Output –21 to –15 dBm

mm

(EIAJ CP-1201) Wavelength 660 nm

Quantization: 16 bits
Sampling frequency: 44.1 kHz
Error correction principle: CIRC
Number of channels: 2
Revolution speed: 500 - 200 rpm

Scan velocity: 1.2 - 1.4 m/s, constant

COAXIAL: 0.5 Vp-p, 75 ohms

(constant linear velocity)

★

A

Disc tray

B

Disc tray open/close button

C

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

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 and plug of the supplied power cord depends on the voltage rating
and destination country.

n Supplied accessories: m AC power cord

m Audio cable with plugs (1 m)

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

GroundbInverted (–)

c

Non-inverted (+)

O

Unbalanced output connectors (analog)

P

AC power connector

★

m Remote Commander RC-18

Digital Processor

mm

m Input format EIAJ CP-1201 compatible

mm

mm

m Digital input level OPTICAL: Input –27 to –15 dBm

mm

(EIAJ CP-1201) COAXIAL: 0.5 Vp-p, 75 ohms

mm

m D/A converter MDS++ type, 24 bits Digital deemphasis

mm
mm

m Frequency response 4.0 to 20,000 Hz ±0.3 dB

mm
mm

m Total harmonic distortion Max. 0.001% (20 - 20,000 Hz, 24-bit input)

mm
mm

m Signal-to-noise ratio 114 dB or better

mm
mm

m Dynamic rang e 110 dB or better (24-bit input)

mm
mm

m Channel separation 110 dB or better

mm
mm

m Output voltage and

mm

impedance

mm

m Output level control 0 to –4 0 dB in 1-dB steps (digital)

mm

Quantization: 16 - 24 bits, linear
Sampling frequency: 32 kHz, 44.1 kHz, 48 kHz,

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

88.2 kHz, 96 kHz

General

mm

m Power requirements AC 120 V/230 V, 50/60 Hz

mm

mm

m Power consumption 14 W

mm
mm

m Maximum Dimensions Width 475.0 mm (19-11/16”)

mm

mm

m Mass 11.7 kg (25.8 lbs) net

mm

mm

m Supplied Remote Commander RC-18

mm

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)

(Voltage as indicated on rear panel)

Height 140.0 mm (5-1/2”)
Depth 395.5 mm (15-9/16”)

16.0 kg (35.3 lbs) in shipping carton

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

B0505 PRINTED IN JAPAN 851-0143-00(AD1)http://www.accuphase.com/