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

Drive signal

Load

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

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

EFM Decoder

& Error

Corrector

Display

Driver

Infrared Receiver

From Remote Commander

Clock Generator

Digital Audio

Data Encoder

Display

DIGITAL SECTION

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

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.

n 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 noise interference, which in turn reduces the error rate.

n Balanced drive circuitry for servo

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

3-Pole

Linear Phase

Low-Pass Filter

Balanced

Buffer

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

n Tray lock prevents resonances

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.

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

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