PRECISION MDSD SA-CD PLAYER

DP-770Accuphase Laboratory, Inc.

1The DP-770 is the succession model of the DP-750
launched in 2018.
It is the superlative integrated SA-CD/CD player thatreflects great technologies of the DP-1000/DC-1000
combo, aiming for the best performance and soundquality.
The newly developed SA-CD/CD drive features a newdamper that effectively reduces vibration, and it shows agreat improvement in the vibration resistance.
The DP-770 has thoroughly reviewed the disc reading
performance and the accuracy of the D/A converter.
It contributes to achieve the excellent low distortion andlow noise performance that surpasses its predecessors,
and to revive beautiful sounds vividly.

1Front display• Easy to see: Sampling Frequency & Number ofeffective bits
Sampling Frequency

Number of effective bit

Accuphase Laboratory, Inc.

2The DP-770 can show the sampling frequency and thenumber of effective bits of all input signals on the frontdisplay.
Quantization bits are counted directly from the raw data
by using a high speed Field Programmable Gate Allay.

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Dimensions and Weight• Dimensions are almost the same, but heavier weight

DP-750DP-770

W: 477 mm
H: 156 mm
D: 394 mm

W: 477 mm
H: 156 mm
D: 395 mm

Weight: 28.2 kg

Weight: 28.5 kg
Long and Heavy
Bridge for quietness

Accuphase Laboratory, Inc.

3The dimensions of the DP-770 are almost the same as
the DP-750.
The weight becomes slightly heavier than the DP-750.
This is due to the long and heavy bridge, mechanicalbase and other frames dedicated to the new SA-CD drive
mechanism.

3Newly designed SA-CD drive mechanism• Offering a quiet listening environment• High torque and less vibration by the outer rotor brushless DC motor
Viscoelastic damper

New SA-CD/CD Drive Mechanism

SA-CD Pickup Unit

Accuphase Laboratory, Inc.

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Creating a quiet listening environment is a vital
component in enjoying music, so the DP-770 enforces
the thorough anti-vibration measures.
The newly designed SA-CD/CD drive is directly mounted
on a completely flat and high-rigidity chassis, with its low
center of gravity, the operational noises are kept to aminimum.
The SA-CD pick up unit is interconnected using newlydeveloped viscoelastic dampers separated from external
vibrations, and an outer rotor brushless DC motor withan accurate rotation axis that guarantees a powerful andstable operation.

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Newly designed SA-CD drive mechanism• Optimizing the vibration-isolation effect with new ViscoelasticDampers• Large Bridge Base as the shielding wall for the airflow

Viscoelastic Damper

Bridge Base

Accuphase Laboratory, Inc.

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The newly developed viscoelastic dampers of two
different hardnesses reduce the magnification of natural
resonances in the objective lens and actuator.
The large bridge base that elegantly finished with a gold
anodized works not only as a vibration absorber, but asa rectifier for the turbulence occurred by disc rotation.

5Internal view
• Completely separated circuit layout & solid construction
Analog Circuit

Glass Cloth
Fluorocarbon Resin
PC board

SystemPower Supply

D/A Conversion
Circuit

Reference Voltage
SourceAccuphase Laboratory, Inc.

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The DP-770 applies the systematical layout. Each circuit
block is logically placed to make the signal path short as
possible.
A D/A conversion circuit is on the right side, and an analog
circuit equipped with glass cloth fluorocarbon resin PC
board is on the left side at the back panel side.
A reference voltage source is on the right side of the SACD drive mechanism, and on the left side, a reinforced
power supply is located.

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Electrical Performance• Ultra Low Noise

DP-750DP-770

2.5μV

2.2μV
12% down
Guaranteed output noise

Accuphase Laboratory, Inc.

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“Ultra Low Noise” is one of the main technical features ofthe DP-770.
The former model, DP-750 has the excellent noise
performance, however, the DP-770 achieves another
12% lower output noise voltage.

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Electrical Performance• Ultra Low THD+Noise0.01

THD + N RATIO [%]0.001

DP-7500.0001

DP-7700.00001
20200

FREQUENCY [HZ]

200020000

THD + Noise to Frequency

Accuphase Laboratory, Inc.

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The DP-770 proudly shows the great THD+Noisecharacteristics which are quite important for sound quality.
The DP-770 makes an almost flat response from the low
frequency through to the high frequency, and it obtains
less than 0.0001% THD+Noise in most frequency ranges.

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D/A converter• 8 parallel D/A converters per channel– ES9028PRO 32bit Hyper Stream Ⅱ DAC– Multiple Delta-Sigma++ for PCM signal– Multiple Double Speed DSD for DSD signal

Accuphase Laboratory, Inc.

9For a D/A converter section, Accuphase adopts the ESS
Technology’s 32bit Hyperstream Ⅱ DAC ES9028PRO.
DP-770 uses the 8 DACs connected in parallel perchannel.
These DACs are essential for Accuphase’s unique
circuits, MSD++ (Multiple Delta-Sigma) converter for
PCM signals and MDSD (Multiple Double Speed DSD)
principle for DSD signals.
The DP-770 has a stronger and more stable reference
voltage source and an ideal ground pattern for DACs,
resulting in even better noise and distortion
performance.
By adopting the ANCC circuit in the I/V converter
section,The DP-770 shows a significant impact on the superb
low noise and distortion characteristics.
9Multiple Delta-Sigma++• Technique to make DACs parallel• Performances improved by a factor of 2.8
PCM signal

I-Vconverterwith ANCC

DAC1
DAC2

D/A output +Voltage
SourceDAC3
DAC4I-Vconverterwith ANCCDAC5I-Vconverterwith ANCCDAC6Voltage
SourceDAC7
DAC8I-Vconverterwith ANCC

D/A output -MDS++ Architecture

Accuphase Laboratory, Inc.

10The MDS++ is a technique to make DACs parallel.
The same digital signal is supplied to each converter, andthe output of each DAC is summed before being sent tosubsequent stages.
The audio signal values are added up, but the conversion
error and noise themselves are canceled.
The ratio between the signal and conversion errors
increases, so the converter performance is improved.
The improvement degree works by a square root of thenumber of DACs.
In the DP-770, all performances are improved by a factor of2.8.

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Multiple Double Speed DSD• In the high frequency, works as a low pass filter• In the low frequency, works as MDS++ Principle
DSD signal

I-Vconverterwith ANCC

DAC1
1/2 CLK Delay

1 CLK width

DAC21/2 CLK Delay

D/A output +Voltage
SourceDAC3
1/2 CLK Delay

DAC4I-Vconverterwith ANCCDAC5I-Vconverterwith ANCC

1/2 CLK Delay

1/2 CLK width

1/2 CLK width

1/2 CLK Delay

DAC61/2 CLK Delay

Voltage
Source

DAC7
1/2 CLK Delay

DAC8I-Vconverterwith ANCC

D/A output -MDSD Architecture

Accuphase Laboratory, Inc.

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“MDSD” stands for Multiple Double Speed DSD.
The DSD signal has a big noise in the high frequency. It
must be removed even if it is outside the range of humanhearing.
The MDSD works as a low pass filter to cut the noise in thehigh frequency and also works as the MDS++ principle toimprove the characteristics in the low frequency.
An important point of MDSD is the delay elements.
The DSD signal in the DP-770 is D/A converted with halfdelayed clocks and is combined when it comes to the output.
As the analog output becomes a half-clock time resolution,it allows the signal to work as a double-speed operation.
This configuration means a moving-average filter.
It works completely as a linear phase low pass filter andremoves the high-frequency noise of DSD signal.

11Post-filter configuration• Fully balanced structure
1st order Low Pass Filter
I-Vconverterwith ANCCDAC1DAC2

2nd order
Low Pass Filter+VoltageSource

DAC3
DAC4I-Vconverterwith ANCCDAC5I-Vconverterwith ANCC

DAC6

DAC8

D/A converter

2nd order

2nd order

Low Pass Filter

Low Pass Filter
2nd order
Low Pass Filter
2nd orderLow Pass Filter

Voltage
SourceDAC7

Dual Direct Balanced Filter-2nd order
Low Pass Filter

I-Vconverterwith ANCC

Balancedoutput

Direct Balanced Filter 1
Direct Balanced Filter 2

2nd order
Low Pass Filter
2nd order
Low Pass Filter

Lineoutput

Post-filter

Accuphase Laboratory, Inc.

12The fully-balanced post-filter eliminates the image noisein high frequency of D/A converter output.
The I-V converter with ANCC* in the D/A converter
circuit works as the 1st order low pass filter as well, andit passes through 2 sections of the 2nd order filters inside
the post-filter, so it is composed of the 5th order low passfilter in total.
The Dual Direct Balanced Filter, that drives two circuitsof Direct Balanced Filter in parallel, is installed at thefinal stage of the post-filter, it contributes to the further
improvement for noise and distortion characteristics.
**The Direct Balanced Filter is a circuit configuration inwhich each output circuit is made independent. This
helps the line output and the balance output notinterfere with each other due to load fluctuations.
* ANCC : “Accuphase Noise and distortion CancelingCircuit” , Refer to Appendix.
12Furthermore• Programmable play mode available

High quality Insulators

Accuphase Laboratory, Inc.

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The DP-770 features the programmable playlists function
with the remote commander RC-140 so that you canenjoy your music in the order you like.
RC-140 also allows you to operate the volume control
and input selection on the Accuphase amplifiers.
The legs are the advanced high-carbon cast ironinsulators with excellent anti-vibration properties, and it
lets you enjoy every detail of music perfectly reproducedby the DP-770.

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Digital Inputs / Outputs• HS-LINK INPUT / OUTPUT– Version1: 192kHz / 24bit, 2.8MHz / 1bit
– Version2: 384kHz / 32bit, 5.6MHz / 1bit

• Coaxial INPUT / OUTPUT– 192kHz / 24bit• Optical INPUT / OUTPUT– 96kHz / 24bit• USB-B INPUT– 384kHz / 32bit– 5.6MHz / 1bit (DoP / ASIO)– 11.2MHz / 1bit (ASIO)

Digital Terminals

Accuphase Laboratory, Inc.

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The DP-770 has 4 digital inputs, Coaxial, Optical, HS-LINK andUSB.
A USB Input accepts 384kHz/32bit-PCM or 11.2MHz-DSD.
DSD data can be received both DoP（DSD over PCM）
and ASIO2.1 (11.2MHz: ASIO only).
An HS-LINK has been evolved into Version2.
The original HS-LINK(Ver.1) transmits and receives
only 192kHz/24bit-PCM or 2.8MHz-DSD,
but Ver.2 comes to be able to transmit and receive
384kHz/32bit-PCM, 5.6MHz-DSD.
The DP-770 automatically recognizes either Ver.1 or Ver.2
transmissions.

14Appendix “ANCC”• ANCC: Accuphase Noise and distortion Canceling Circuit– To detect and cancel the noise and distortion at the input stage of
I-V converter.
I-V converter
RCurrent input

Voltage output

Injects the cancelingcurrent

Detection amp

ANCCDetects noise anddistortion components

Accuphase Laboratory, Inc.

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ANCC: “Accuphase Noise and distortion CancelingCircuit” is installed in the I-V converter.
Canceling noise and distortion is realized by detecting
the components of noise and distortion at the input stageof an I-V converter module, and also by injecting thecanceling current which contains the reversed polarity of
those components.

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