● MDSD type D/A converter using eight parallel circuits ● Direct Balanced
Filter with totally separate line and balanced signal paths ● Support for
5.6448 MHz 1-bit 2-channel DSD and 384 kHz 32-bit 2-channel PCM ● Six
digital interface inputs including HS-LINK and USB ● Phase selector forbalanced outputs ● Sampling frequency and quantization bit display for input
signal ● Separate power transformers for digital and analog sections

State-of-the-Art Digital Processor — Innovative MDSD (Multiple Double Speed DSD)
digital processing circuitry with double-speed high-precision moving-average filter
circuit configuration for straight D/A conversion of DSD signal. Support for playbackof high-resolution sources in 5.6448 MHz (1-bit 2-channel DSD) and 384 kHz (32-bit2-channel PCM) format. Six digital inputs including HS-LINK and USB. Informative
readout shows sampling frequency and number of quantization bits of input source,
based on actual measurement.
In 2011, Accuphase introduced the ultra high-end
separate type Precision SA-CD/CD Transport DP-900
and Precision MDSD Digital Processor DC-901 combo,
which was positioned as the second entry in thecompany's 40th anniversary commemorative model
lineup. In 2013 Accuphase followed these with theintegrated type SA-CD/CD player DP-720 featuring afurther evolved MDSD D/A converter with support for avariety of sources. Both the technical excellence andstunning sound quality of these products were highly
lauded, earning them a secure place as referencecomponents in Japan as well as abroad.
The DC-37 inherits the outstanding technology of theDC-901 and DP-720, while opening a new chapter inultra-advanced and innovative digital signal processing

technology. It features an MDSD type D/A converter
that achieves straight conversion of the DSD signal andsupports 5.6448 MHz (1-bit 2-channel DSD) sources.
In keeping with this development, the HS-LINK
interface has also been upgraded to Version 2 withsignificantly expanded sampling frequency andquantization support up to 5.6448 MHz (1-bit 2-channelDSD) and 384 kHz (32-bit 2-channel PCM).
The DC-37 also offers convenience and flexible
functionality. External digital sources can be connected
via a total of six digital inputs: HS-LINK, COAXIAL 1,COAXIAL 2, OPTICAL 1, OPTICAL 2, and USB.
Accepting digital data for example from a computer orother components, this new standalone processor turns
the information into musical signals of unprecedentedquality. A front panel display shows not only the sampling
frequency of the selected source, but also the number ofquantization bits, based on actual measurement of thesignal. Two completely separate power supplies, eachwith a dedicated power transformer, are used for thedigital and analog sections, to prevent any possibility of
RF noise or electrical interference that could degrade thesonic purity of the output.
The DC-37 is a digital processor that redefines thestate-of-the art and has its sights firmly set on the future,including computer-based and high-resolution audio. Only
strictly selected circuit components, materials and otherparts of the highest quality are used, resulting in an
immense richness of information that translates into aspectacular musical experience.

Features and Functions■ Ample clean power is provided by separate power supplies
for the digital and analog sections, each with a dedicatedpower transformer and large filtering capacitors.
■ Ultra-high-speed FPGA (Field Programmable Gate Array)harnesses digital processing power to implement innovative
MDSD reproduction with double-speed high-precision
moving-average filter circuit.
■ MDS++ type D/A converter with eight circuits driven inparallel.
One 32-bit Hyperstream™ DAC chip (ES9018 from ESS
Technology Inc.) is used per channel, each comprising eightcircuits driven in parallel. This improves overall performanceby a factor of about 3 as compared to a single converter circuit,thereby achieving outstanding low-distortion results.
■ Direct Balanced Filter uses high-precision op-amps andperforms totally separate analog filtering for line andbalanced signal paths, to prevent any risk of interference
when both are used simultaneously.

Power transformer
Assembly with MDSD and analog output circuitry

High-precision op-amp

Power supply assembly

Input selector

USB chipAssembly with 6 digital inputs■ Six digital inputs: HS-LINK, coaxial (2), optical (2), USB.
■ Line and balanced analog outputs (1 each). Phase selector
switch for balanced output.

Digital signal processing assembly

Phase selector

Parts selected for high sound quality and reliability

Block Diagram
HS-LINK

HS-LINK
Receiver

MDSD（Multiple Double Speed DSD）System
Delay

Coaxial 1

Coaxial 2

CoaxialReceiverDelay
DSD Signal

Interface
Decoder
Optical 1

OpticalReceiverOptical 2

OpticalReceiverInfrared
ReceiverFrom
Remote Commander

DAC×8MDSD（Multiple Double Speed DSD）System
DelayUSB
ReceiverDSD Signal

MasterControlComputerKey
MatrixDAC×8

PCM Signal

DisplayMDS＋＋
D/A Conversion

Line

Left
AnalogOutputs

5-PoleButterworth
Low-Pass Filter

5-PoleButterworth
Low Pass Filter

PCM Signal

Delay

5-PoleButterworth
Low Pass Filter

D/A Conversion

CoaxialReceiver

DigitalInputs

USB

MDS＋＋

5-PoleButterworth
Low Pass Filter

5-PoleButterworth
Low Pass Filter

5-PoleButterworth
Low Pass Filter

BalancedLine

RightAnalog
Outputs

BalancedInnovative Digital Processing: MDSD (Multiple Double Speed DSD) Playback Principle
Double Speed Moving Average Filter Circuit
Digital input
DSD signal

Group 1Delay
device32-bit Hyperstream™ DAC chips

Delaydevice5.6448 MHz 1-bit
2-channel DSD

In the DC-37, the eight circuits of the 32-bit Hyperstream™
DAC chip (ES9018 from ESS Technology Inc.) are driven
in parallel (using clock shift for DSD), thereby improvingoverall performance by a factor of about 3, as compared
to a single converter circuit.
Because the performance improvement afforded by theMDS++ principle is independent of signal frequency andsignal level, output signal noise at very low levels is
also successfully minimized, a feat that is very difficult
to achieve with conventional delta-sigma converters.
By locating a dedicated quartz oscillator very close to
the ES9018 chip and using it as a master clock to drive
the D/A converter in asynchronous mode, jitter is alsosignificantly reduced.

Sampling frequency and number ofquantization bits shown on display

DelaydeviceDelaydevice

Delayed by1/ 2clock cycle

Delayed by 1 clock cycle

Delayed by 1 clock cycle

Delaydevice

BIT

Indicates actual number ofbits (in 1-bit steps) as
input to DAC.

−DAC 6I-V

converter
Delayed by 1 clock cycle

Delaydevice

DAC 7

Normalphase output

DAC 8
Delayed by 3 clock cycles

Group 2Current summing /Reverse phase
outputI-V conversion(Overall summing of 8 DAC signals)

HS-LINK Ver. 2
HS-LINK Ver. 2 is an upgraded version of the Accuphase HS-LINK interface,providing significantly expanded sampling frequency and quantization support
up to 5.6448 MHz (1-bit 2-channel DSD) and 384 kHz (32-bit 2-channel PCM).
● The DC-37 supports HS-LINK Ver. 2 and is therefore compatible with both
HS-LINK and HS-LINK Ver. 2 signals.

0.00300.00200.00100.0005

2030

50

100

200

500

1k

2k 3k

5k

10k

20k
〔Hz〕

HS-LINK

HS-LINK Ver.2

Total harmonic distortion (incl. noise) vs. frequency response

Sampling frequency/Quantization bits

Eight D/A converter circuits driven inparallel ensure outstanding performancein all aspect, including superb S/N ratio
and amazingly low harmonic distortion.

32.0 kHz, 44.1 kHz, 48.0 kHz, 32.0 kHz, 44.1 kHz, 48.0 kHz,88.2 kHz, 96.0 kHz, 176.4 kHz, 88.2 kHz, 96.0 kHz, 176.4 kHz,
192.0 kHz, 352.8 kHz, 384.0 kHz /192.0 kHz /16 to 32-bit 2-channel PCM
16 to 24-bit 2-channel PCM
2.8224 MHz /1-bit 2-channel DSD

Indicates locked-in sampling
frequency (kHz) of signal.

＋

DAC 5

Delay
device0.0002

Display example

converter

DAC 3

DAC output(Reference waveform)

0.0003

FREQUENCY

Reverse phaseoutput

DAC 40.0100

0.0001

DAC 2I-VDelayed by 1 clock cycle

THD + NOISE vs. FREQUENCY〔%〕Normal phase output

DAC 1

Delayed by 3.5 clock cycles

0.0050

The readout shows the sampling frequency ofthe source chosen by the input selector, as wellas the number of quantization bits input to theDAC, as determined by actual measurement.

MDS＋＋ D/A Conversion System(Input signal slightly shifted by 7 delay devices)

2.8224 MHz, 5.6448 MHz /1-bit 2-channel DSD＊ HS-LINK is a registered trademark of Accuphase Laboratory, Inc.
＊ HS-LINK cable can be used both for HS-LINK and HS-LINK Ver. 2
signal transmission.

Performance Graphs

Connection Example: DC-37 has six digital inputs

DP-900HS-LINK

DIGITAL OUT

T-1100−20

DIGITAL OUT−40

HS-LINK cable

HS-LINK cable connection
supports transmission of both
SA-CD and CD signals with asingle cable.

LINEARITY

Analog output〔dB〕0Digital component suchas CD transport−60

Coaxial cable−80＊

Optical fiber cable
USB cable

USB port−100

Computer−120−140−120−100−80−60−40−200
Digital input〔dB〕

Linearity (digital input vs. analog output)

Digital inputs(6 connectors)

FREQUENCY RESPONSE〔dB〕
1086DC-37

4Analog outputs(Use either)

The DC-37 has a total of six digital inputs that
accept signals from external equipment, such as
for example the DP-900, a computer or othercomponents. The processor in the DC-37 thenconverts these digital data into high-quality musicsignals for playback.

Audio cable

20＊ For playback of material via
the USB port, it is necessary
to install software from thesupplied “USB Utility 2”
CD-ROM on the computer.
(Not required with an AppleMacintosh computer.)−2−4−6−8−1020 3050100200500

1k2kFrequency response

Preamplifier

3k5k

10k20k〔Hz〕

DC-37 Guaranteed Specifications◆ Front panel[Guaranteed specifications measured according to JEITA standard CP-2402A]

w Quantization bit number

e Output level display

displayq Sampling frequency
displayr Power switchy Output level control buttons
DOWN / UPt Input selector buttons

USB / OPT 1, 2 / COAX 1, 2 / HS-LINK◆ Rear panelu Digital inputs

i Analog outputs

HS-LINK / COAXIAL 1, 2OPTICAL 1, 2 / USB

BALANCED / LINEo Balanced output phase !0 AC power connector ★
selector switch■ Supplied accessories:

AC power cord
● Audio cable with plugs (equivalent to ASL-10, 1 m)
● “USB Utility 2” CD-ROM (Windows Install Disc)● “USB Utility 2” Setup Guide● Cleaning cloth●● Digital inputs

HS-LINK

Connector type: RJ-45
Suitable cable: Dedicated HS-LINK cable
COAXIAL
Format:IEC 60958 AES-3 compliant
Suitable cable: 75-ohm coaxial digital cable
OPTICAL
Format:JEITA CP-1212 compliant
Suitable cable: JEITA standard optical fiber cable
USB
Format:USB 2.0 Hi-Speed (480 Mbps)
compliantSuitable cable: USB 2.0 cable with Type B connector● Sampling frequencies HS-LINK
32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz,176.4 kHz, 192 kHz, 352.8 kHz, 384 kHz(16 to 32-bit 2-channel PCM)
2.8224 MHz, 5.6448 MHz (1-bit 2-channel DSD)
COAXIAL 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz,176.4 kHz, 192 kHz (16 to 24 bit 2-channel PCM)
OPTICAL 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz(16 to 24 bit 2-channel PCM)
USB
32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz,176.4 kHz, 192 kHz, 352.8 kHz, 384 kHz(16 to 32 bit 2-channel PCM)
2.8224 MHz, 5.6448 MHz (1-bit 2-channel DSD)
● D/A converter
MDSD principle (DSD signal)
MDS++ principle (PCM signal)● Frequency response 0.5 to 50,000 Hz +0, −3.0 dB● Total harmonic distortion 0.0006％ (20 to 20,000 Hz)● Signal-to-noise ratio 119 dB● Dynamic range
116 dB● Channel separation
117 dB (20 to 20,000 Hz)
BALANCED: 2.5 V 50 ohms, balanced XLR type● Output voltage andimpedanceLINE:
2.5 V 50 ohms, RCA phono jack0 dB to -80 dB (digital)● Output level control● Sampling frequency / 2-channel PCM
Quantization bit display
32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz,176.4 kHz, 192 kHz, 352.8 kHz, 384 kHz
0 to 32 bit (0: No data)
2-channel DSD
2.8224 MHz, 5.6448 MHz
1 bit● Power requirements 120 V, 220 V, 230 V AC (voltage as indicated on rear panel),
50/60 Hz● Power consumption
10 W● Maximum dimensions Width
HeightDepth● Mass465 mm (18.31”)
114 mm ( 4.49”)385 mm (15.16”)

14.4 kg (31.7 lbs)
20.0 kg (44.1 lbs) in shipping carton

Remarks★ This product is available in versions for 120/220/230 V AC. Make sure that the voltage shown on the rear panel matches the AC line voltage in your area.
★ 230 V version has an Eco Mode that switches power off after 120 minutes of inactivity.
★ The shape of the AC inlet and plug of the supplied power cord depends on the voltage rating and destination country.

●The specifications and appearance of this product are subject to change without notice.

5年間保証

L1405Y PRINTED IN JAPAN 850-2190-00（B1）