DCT-42

Digital/Analog Stereo Audio Amplifier

Operation Manual

DISCLAIMERS
The information in this manual has been carefully checked andis believed to be accurate. Cypress Technology assumes noresponsibility for any infringements of patents or other rights of third
parties which may result from its use.
Cypress Technology assumes no responsibility for any inaccuracies
that may be contained in this document. Cypress also makes nocommitment to update or to keep current the information containedin this document.
Cypress Technology reserves the right to make improvements to thisdocument and/or product at any time and without notice.

COPYRIGHT NOTICE
No part of this document may be reproduced, transmitted,transcribed, stored in a retrieval system, or any of its part translated
into any language or computer file, in any form or by any means—electronic, mechanical, magnetic, optical, chemical, manual, orotherwise—without express written permission and consent fromCypress Technology.
© Copyright 2017 by Cypress Technology.
All Rights Reserved.

TRADEMARK ACKNOWLEDGMENTS
All products or service names mentioned in this document may betrademarks of the companies with which they are associated.

SAFETY PRECAUTIONS
Please read all instructions before attempting to unpack, install oroperate this equipment and before connecting the power supply.
Please keep the following in mind as you unpack and install thisequipment:•Always follow basic safety precautions to reduce the risk of fire,electrical shock and injury to persons.

•To prevent fire or shock hazard, do not expose the unit to rain,moisture or install this product near water.

•Never spill liquid of any kind on or into this product.

•Never push an object of any kind into this product through any
openings or empty slots in the unit, as you may damage parts
inside the unit.

•Do not attach the power supply cabling to building surfaces.

•Use only the supplied power supply unit (PSU). Do not use the PSU
if it is damaged.

•Do not allow anything to rest on the power cabling or allow any
weight to be placed upon it or any person walk on it.

•To protect the unit from overheating, do not block any vents or
openings in the unit housing that provide ventilation and allow forsufficient space for air to circulate around the unit.

REVISION HISTORY
VERSION NO.

DATE (DD/MM/YY) SUMMARY OF CHANGE

VS1

11/12/17

Preliminary release

CONTENTS
1. Introduction������������������������������������������������������1
2. Applications�����������������������������������������������������1
3. Package Contents������������������������������������������1
4. System Requirements��������������������������������������1
5. Features������������������������������������������������������������2
6. Operation Controls and Functions�����������������2
6.1 Front Panel������������������������������������������������� 2
6.2 Rear Panel�������������������������������������������������� 3
6.3 RS-232 Protocol������������������������������������������ 4
6.4 RS-232 Commands������������������������������������ 5
7. Connection Diagram��������������������������������������7
8. Specifications��������������������������������������������������8
8.1 Technical Specifications�������������������������� 8
8.2 Audio Specifications��������������������������������� 9
9. Acronyms�������������������������������������������������������10

1. INTRODUCTION
This Digital/Analog Stereo Audio Amplifier is a compact, highperformance, Class-D amplifier which features both digital andanalog inputs. Volume and input selection can be controlled via
front panel buttons or RS-232. LED indicators provide selection andfeature information. This unit is designed for both the commercial andresidential user who needs to output a high quality source to local
analog speakers.

2. APPLICATIONS• Entertainment rooms & home theaters• Home sound system extension• Lecture hall presentations• Conference and meeting room audio system sharing• Showroom audio extension

3. PACKAGE CONTENTS• 1×Digital/Analog Stereo Audo Amplifier• 2×Terminal Blocks (2-Pin)• 1×Terminal Block (3-Pin) to RS-232 (9-Pin D-Sub) Cable• 1×24V/2.7A DC Power Adaptor• 1×Power Cord
• 1×Operation Manual

4. SYSTEM REQUIREMENTS• Audio source equipment such as a PC, media player, or smart
phone.
• Analog audio receiving equipment such as unpowered speakers.

1

5. FEATURES• Compact and cost-effective amplifier design• High performance and efficient Class-D amplifier• Selectable analog and digital audio inputs• Volume control with mute
• Simple control via front panel buttons and RS-232

6. OPERATION CONTROLS AND FUNCTIONS6.1 Front Panel
MUTE

PW SOURCE OPT.

LINE IN

MUTE

123VOL-VOLUME LEVEL+451 MUTE Button: Press to toggle between muting and unmuting theaudio output.

Note: Press and hold this button for 3 seconds to put the unit into
stand-by mode. Press and hold the button again for 3 seconds toreturn to normal operation.

2 PW LED: This LED will illuminate bright green to indicate the unit is on
and receiving power. When the unit is in stand-by mode the LED
will illuminate dim green.
MUTE LED: This LED will illuminate to indicate the when the audio
output is muted.

3 SOURCE Button & OPT./LINE IN LEDs: Press this button to toggle

between the line in and optical inputs. The LEDs will illuminate toindicate which source is currently selected.

4 VOL −/+ Buttons: Press or hold the −/+ (minus/plus) buttons toincrease or decrease the audio output volume.

5 VOLUME LEVEL LEDs: These 5 LEDs will illuminate progressively from2

left (lowest) to right (highest) to indicate the current output volumelevel.
Note: The full volume range is from -80dB to +20dB (100 steps) andthe LEDs will be lit proportionally to this range.

6.2 Rear Panel-T R+RIGHT

LINE INOPT.

RS-232123-+LEFT

4DC 24V

5

1 LINE IN: Connect to the stereo analog output of a device such asa CD player or PC.

2 OPT. IN: Connect to the optical audio output of a device suchas a media player or game console using an appropriate opticalcable.

3 RS-232: Connect directly to a PC, laptop or other serial control

device with a 3-pin adapter cable to send RS-232 commands tocontrol the unit.

4 RIGHT/LEFT OUT: Connect to unpowered speakers (20W, 4Ω) for
stereo analog audio output.

5 DC 24V: Plug the 24V DC power adapter into the unit and connect
it to an AC wall outlet for power.

3

6.3 RS-232 Protocol
9-Pin D-Sub
Pin

Definition

1

NC

2

TxD/RxD

3

RxD/TxD

4

NC

5GND

6NC

7

NC

8

NC

9NC

Terminal Block

Unit

Pin

Definition

Definition

◄1

RxD

◄

TxD

►2TxD

►RxD

►3GND

►GND

Baud Rate: 19200bps
Data Bits: 8Parity Bits: None
Stop Bits: 1Flow Control: None4

6.4 RS-232 Commands
COMMANDDESCRIPTION AND PARAMETERS

System Commands
HELP

Show the full command list.

?Show the full command list.

GET FW VERShow the unit’s firmware version.

GET MODEL NAME

Show the unit’s model name.

SET FACTORY DEFAULTReset all settings to the factory
defaults.

SET POWER N1

Set the units power state to on or
stand-by.
Available values for N1:
ON		[Power On]

STANDBY[Stand-by Mode]

GET POWERShow the unit’s current power state.

SET SYSTEM REBOOT

Reboot the unit.

COMMANDDESCRIPTION AND PARAMETERS

Audio Commands
SET AUDIO OUT A MUTE N1

Enable or disable mute on the audiooutput.
Available values for N1:

GET AUDIO OUT A MUTE

OFF		[Un-Mute]ON		[Mute]Show the current audio output mutestate.

SET AUDIO OUT A ROUTE N1

Set the audio input source.
Available values for N1:
1		

[Line In]

2		 [Optical]
GET AUDIO OUT A ROUTE

5Show the current audio input source.

COMMANDDESCRIPTION AND PARAMETERS

Audio Commands
SET AUDIO OUT A VOLUME N1

Set the audio output volume.
N1 = 0 ~ 100[dB Units]

Volume Mapping Table:
100		[+20dB]

80		

[0dB]

60		

[-20dB]40		

[-4dB]

20		

[-60dB]0		 [-80dB]
SET AUDIO OUT A VOLUME UP

Increase the audio output volume by
1 step (up to a max of 100).

SET AUDIO OUT A VOLUME DOWN

Decrease the audio output volumeby 1 step (down to a min of 0).

GET AUDIO OUT A VOLUME

Show the current audio output
volume.

Note: Commands will not be executed unless followed by a carriage
return. Commands are not case-sensitive.

67. CONNECTION DIAGRAMCD Player

Game Console

Stereo Analog
Audio InputOptical Digital
Audio Input

LINE IN

OPT.

-T R+

RS-232

RIGHT-+LEFT

DC 24V

RS-232
RS-232 Equipped
PC/Laptop

Stereo Analog
Audio Output

UnpoweredSpeakers

7Power Supply

8. SPECIFICATIONS
8.1 Technical Specifications
Input Ports

1×Optical (S/PDIF Audio)
1×3.5mm (Stereo Audio)

Output Ports

2×Terminal Block (Speakers)

Control Interface

1×RS-232 [Terminal Block]Power Supply

24V/2.7A DC (US/EU standards, CE/FCC/
UL certified)

ESD Protection

Human Body Model:±8kV (Air Discharge)±4kV (Contact Discharge)

Dimensions

128mm×25mm×108mm (W×H×D)[Case Only]
128mm×25mm×110mm (W×H×D)[All Inclusive]

Weight

380g

Chassis Material

Metal

Silkscreen ColorBlack

Operating Temperature

0˚C - 40˚C/32˚F - 104˚F

Storage Temperature−20˚C - 60˚C/−4˚F - 140˚F

Relative Humidity

20 - 90% RH (Non-condensing)Power Consumption

42W

88.2 Audio Specifications
Amplifier Output
Output Power

20W+20W

THD+N

0.02% (Po = 1W, Load = 4Ω)Frequency Response

20Hz ~ 20kHz

SNR

95dB

Crosstalk

80dB

Optical (S/PDIF) Input
Sampling Rate

44.1, 48, 88.2, 96, 176.4, 192 (kHz)Line-level Input
Input Sensitivity

210mV

Input Impedance

30KΩ

Audio Format

LPCM 2.0

Full Scaler

2.1Vrms

THD+N

85dB (Level = -1dB)

Frequency Response

20Hz ~ 20kHz (±0.5dB)

SNR

95dB

Crosstalk

80dB

99. ACRONYMS
ACRONYMCOMPLETE TERM

dB

DecibelHzHertz

kHz

Kilohertz

OPT

OpticalS/PDIF

Sony/Philips Digital Interface Format

SNR

Signal-to-Noise Ratio

THD+N

Total Harmonic Distortion plus NoiseVOL

VolumeW

Watts

ΩOhm10CYPRESS TECHNOLOGY CO., LTD.
www.cypress.com.tw