AUDAC DPA74 Installation and operating instructions

PROFESSIONAL AUDIO EQUIPMENT
DPA74/154 Quad Channel Class-D Amplifier
User Manual &
Installation Guide
DPA74/154
A
U
DA
C

AUDAC PROFESSIONAL AUDIO EQUIPMENT
User Manual & Installation Guide
AUDAC
http://www.audac.eu
[email protected]

2
INTRODUCTION..................................................................................................................................................................................................................... 3
ENVIRONMENT ...................................................................................................................................................................................................................... 4
SAFETY REQUIREMENTS ................................................................................................................................................................................................... 5
CAUTION –SERVICING...................................................................................................................................................................................................... 5
OVERVIEW FRONT AND REAR PANEL .......................................................................................................................................................................... 6
FRONT PANEL OVERVIEW................................................................................................................................................................................................ 6
FRONT PANEL DESCRIPTION .......................................................................................................................................................................................... 6
REAR PANEL OVERVIEW .................................................................................................................................................................................................. 7
REAR PANEL DESCRIPTION ............................................................................................................................................................................................. 7
CONNECTING THE AMPLIFIER........................................................................................................................................................................................ 8
INPUT CONNECTIONS ........................................................................................................................................................................................................ 8
OUTPUT CONNECTIONS .................................................................................................................................................................................................. 10
CONNECTIONS STANDARDS.......................................................................................................................................................................................... 11
BLOCK DIAGRAM ............................................................................................................................................................................................................... 12
ADDITIONAL INFORMATION.......................................................................................................................................................................................... 13
TECHNICAL SPECIFICATIONS ....................................................................................................................................................................................... 13
PERSONAL NOTES............................................................................................................................................................................................................... 14
Index

3
Introduction
This section briefly describes the possibilities of the DPA74/154 Class-D Power
Amplifiers.
he DPA series amplifiers are digital power amplifiers designed to meet the specialized
needs of sound contractors. They are designed in six different models of Class D
power amplifiers, divided in three different architectures to meet the requirements
for all kinds of applications.
They combine the best of all features in one single series of amplifiers, providing an
outstanding sound quality with all the known advantages of Class D Amplifiers. Such as the
excellent efficiency and very low heat dissipation. And due to the complete passively cooled
entity only a minimal of maintenance is needed, while ensuring maximum reliability.
The small size of a single rack space make them very interesting for fixed rack mount as well
as mobile applications.
The DPA74 and DPA154 are four channel Class D amplifiers capable of delivering a power
up to 4 x 150 Watt., with various specific features and advanced protection circuitry which
protects against DC malfunctioning, short circuit, overheating and overload.
The signal input connections are accommodated with balanced XLR connectors. The
operation mode can be selected between Stereo mode, Bridge mode and Parallel mode.
The output connections are accommodated with Euro-Terminal blocks
T

4
Environment
Do not place this unit in an enclosed environment such as a bookshelf or closet. Ensure
that there is adequate ventilation to cool the unit.
Do not place the unit in environments which contain high levels of dust, heat, moisture or
vibration.
Do not use the unit near water or other liquids. Make sure no water or other liquids can be
spilled, dripped or splashed on the unit.
This unit was developed for indoor use only. Do not use it outdoors.
Do not place objects on top of the unit.
Place the unit on a stable base or mount it in a stable 19” rack.
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5
Safety Requirements
Always handle the unit with care.
Only use a grounded socket outlet and a power cord with grounding plug to plug in the
unit.
This unit is not a toy. It should not be operated by children.
Do not stick objects through the openings.
Do not open the unit (risk for electrical shock).
CAUTION – SERVICING
This unit contains no user serviceable parts. Refer all servicing to qualified
service personnel. Do not perform any servicing unless you are qualified to do
so.
Note
This product conforms to the following European Standards: EN 50081-1: 1992, EN
50082-1: 1992, EN 60065: 19



6
Overview front and rear panel
Front panel overview
Description
1. Power switch:
By means of the power switch, the amplifier can be turned ON and OFF. When the amplifier is
switched on, the blue LED located above the power button will illuminate.
2. Gain control knobs:
These rotary gain control knobs allow you to adjust the level for each individual channel.
3. Indicator LED’s:
These LED’s indicate the operation of the amplifier. There are three LED’s provided. A signal
indicator, a Clip indicator, and a Protect indicator. The green signal indicator LED’s will light up
when the input channel exceeds -20 dBu. The yellow clip LED’s will illuminate when the channel’s
output is being overdriven, and the two red protect indicators illuminate when the thermal
compression begins, or any fault is detected.
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1. Power Switch
3. Indicator LED’s
2. Gain controls

7
Rear panel overview
Description
4. Power inlet:
The mains power supply (100~240V AC / 50~60 Hz) has to be applied to this AC power inlet.
The connection is made by an IEC power connector and is fitted with a fuse. When replacing the
fuse, make sure that the value of the replacement fuse matches the value of the original fuse.
(T4AL/250V for DPA74 & T6.3AH/250V for DPA154)
5. Loudspeaker connections:
The loudspeaker output connections are performed by means of Euro Terminal Blocks. A detailed
description about the best method for connecting the loudspeakers for every application can be
found in the next chapter, connecting the amplifier.
6. Input connections:
The input connections of the amplifier are performed using balanced XLR connectors. Every
channel has an XLR input connector on which the input signal from the signal source, pre-
amplifier or mixer should be connected.
7. Operation mode switch:
For every two channels is an “Operation mode switch” provided. By means of this switch, the
operation mode of the amplifier can be selected between standard stereo mode, parallel mode and
bridge mode. For standard stereo applications, this switch should be turned to center position for
“Stereo” mode.
4.
A
C
p
ower inlet with fuse
5. Louds
p
eaker connections 7. O
p
eration mode switch:
6. In
p
ut connections

8
Connecting the Amplifier
Input connections
The input connections of the amplifier should be made by connecting the signal from the signal
source, pre-amplifier or mixer to the balanced XLR input connections.
Next to every pair of input channel connectors is an operational mode switch provided. By means
of this switch, the operational mode of the amplifier can be selected. There are three different
operational modes available:
1) Stereo Mode:
This is the default mode how the amplifier is set in the factory, and will be the most
common used setting for most applications (Center position of the switch). When
both switches are set in Stereo mode, all the four amplifier channels work
separately, and amplify the signal which is available on the corresponding balanced
XLR signal input.
2) Bridge mono Mode:
In bridged mono mode, the power of two output channels is merged to deliver
double the power to one single 8 Ohm load. The mode selection switch should be
positioned in the Bridge position (Left position of the switch).
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9
The signal sources should only be connected to the balanced XLR connectors of
Channel 1 and Channel 3.
For more information about how the loudspeakers should be connected in bridge
mode, refer to the “Output Connections” section of this user manual.
3) Parallel Mode:
In parallel mode (Right position of the switch), the amplifier is configured in a way
that only the signal applied to the XLR input connector of Channel 1 and Channel
3 will be used, and will be amplified by all four output channels. (input channel 1
through output channels one and two, and input channel three through output
channels three and four)
The output level of both channels can be individually controlled by means of the
rotary controls on front of the amplifier.

10
Output connections
The loudspeaker connections for every output channel are performed with a two pin Euro-
Terminal block connector.
Stereo Mode:
Stereo mode will be the most commonly used operation method for this amplifier.
The loudspeakers of each channel can be connected with a separate two-core
connection cable to the Euro-Terminal block output connectors.
Channel 4 Channel 1
Channel 2Channel 3

11
1) Bridge mono Mode:
When the amplifier is switched in bridge mode, there will be one load connected
to two amplifier outputs. This load should be connected between the + terminal
of Channel 1 and the – terminal of Channel 2. (And the + terminal of Channel 3
and the – terminal of Channel 4)
Channel 1+2
Channel 3+4
2) Parallel Mode:
When the amplifier is switched in parallel mode, the connections for the
loudspeakers should be made in the same way as Stereo mode.
Note
Do not connect any 100V line transformers to the loudspeaker outputs of the amplifier.
Connection standards
The in- and output connections of AUDAC audio equipment are performed corresponding to
international wiring standards for professional audio equipment.
XLR:
1 = ground / shield
2 = +sig
3 = -sig
XLR female:
XLR male:

12
Block Diagram
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13
Additional Information
Technical specifications
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DPA74
DPA154
Performance
Rated power
(1 kHz, THD 1%)
Stereo @ 8 Ohm 4 x 50 Watt 4 x 80 Watt
Stereo @ 4 Ohm
4 x 75
Watt
4 x 150
Watt
Brid
g
e @ 8 Ohm
2 x 150
Watt
2 x 300
Watt
Input Sensitivity
(
Im
p
edance 20 kOhm
)
+ 4 dBu
Fre
q
uenc
y
res
p
onse
(
± 1 dB
)
20 Hz –
20 kHz
Si
g
nal to Noise ratio >
90
dB
Channel se
p
aration >70 dB
THD at 1 kHz
(
1/2 rated
p
ower
)
Less than 0.1%
Operation Temperature / Humidity at
non condensin
g
0° ~ 40°C at 95% Humidity
Indicators Protect
(
DC, Thermal, Overload
)
Cli
p
(
0 dBr
)
Si
g
nal
(
-26 dBr
)
Power su
pp
l
y
100~240V AC / 50~60 Hz
Construction
Construction Steel
Coolin
g
Convection cooled
Mountin
g
19” Rack
Unit Height 1 HE
Dimensions
(
W x H x D
)
482 x 44 x 330 mm
Color Black
Net Weight 4.57 Kg 4.82 Kg

14
Personal notes