Gentec PA70W User manual

PA70W
40 Watt Power Amplifier
All Rights Reserved
Version: PA70W/100V_2014V1.3
User Manual

40W Power Amplifier
Safety Operation Guide
In order to guarantee the reliable operation of the equipments and safety of the staff,
please abide by the following proceeding in installation, using and maintenance:
1) The system must be earthed properly. Please do not use two blades plugs and
ensure the alternating power supply ranged from 100v to 240v and from 50Hz to
60Hz.
2) Do not put the switcher in a place of too hot or too cold.
3) As the power generating heat when running, the working environment should be
maintained fine ventilation, in case of damage caused by overheat.
4) Please cut off the general power switch in humid weather or left unused for long
time.
5) Before following operation, ensure that the alternating current wire is pull out of the
power supply:
Take off or reship any components of the equipment.
Take off or rejoin any pin or other link of the equipment.
6) As to non-professional or without permission, please DO NOT try to open the casing
of the equipment, DO NOT repair it on your own, in case of accident or increasing
the damage of the equipment.
7) DO NOT splash any chemistry substance or liquid in the equipment or around.

40W Power Amplifier
NOTICE: Please read this user manual carefully before using this product. Pictures
shown in this manual is for reference only, different model and specifications are
subject to real product.
This manual is only for operation instruction only, not for any maintenance usage.
The functions described in this version are updated till October 2014. Any
changes of functions and parameters since then will be informed separately.
Please refer to the dealers for the latest details.
All rights reserved. No part of this publication may be copied or reproduced
without permission.
All product function is valid till 2014-10-23.

40W Power Amplifier
Table of Contents
1. Introduction .................................................................................................................2
1.1 Introduction to 40 Watt Power Amplifier.............................................................2
1.2 Features ............................................................................................................2
1.3 Package Contents .............................................................................................2
2. Panel Description........................................................................................................3
2.1 Front Panel ........................................................................................................3
2.2 Introduction of Rear Panel.................................................................................4
3. System Connection.....................................................................................................5
3.1 Usage Precautions ............................................................................................5
3.2 System Diagram ................................................................................................5
3.3 Audio Signal Connection....................................................................................5
3.3.1 Audio Output............................................................................................5
3.3.2 Audio Inputs.............................................................................................6
3.4 System Applications...........................................................................................7
4. System Operations .....................................................................................................7
4.1 Operations of Front Panel..................................................................................7
4.1.1 Audio switching........................................................................................7
4.1.2 Volume/EQ controlling .............................................................................8
4.2 Operations of IR Remote ...................................................................................8
4.3 Operations of Control Software .........................................................................9
4.3.1 Connection with Computer ......................................................................9
4.3.2 Installation/uninstallation of RS232 Control Software ..............................9
4.3.3 Running Environment ............................................................................11
4.3.4 Function Settings................................................................................... 11
4.3.5 RS232 Communication Commands ......................................................12
5. Specifications............................................................................................................14
6. Panel Drawing ..........................................................................................................15
7. Troubleshooting and Maintenance............................................................................16
8. After-sales Service....................................................................................................17

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1. Introduction
1.1 Introduction to 40 Watt Power Amplifier
40 Watt Power Amplifier is a 40 Watt power amplifier (Class-D) with output alternatively
at 70V or 100V. It has 2 stereo inputs (1x3.5mm jack for line in, 2xRCA for L&R), 1
digital input & 1 balanced MIC. It is integrated with powerful functions, including
ducking function, EQ control, MIC mixer etc, and MIC input supports 3 levels with
condenser MIC, dynamic MIC & line audio input.
As for power amplifier we have normally voltages at 70V and 100V for different
countries, but 40 Watt Power Amplifier is designed to integrate with both voltages to
meet different requirements.
1.2 Features
Mono audio output at 40Watt.
Switchable between 70V and 100V.
Ducking function.
16 ID codes for controlling between different 40 Watt Power Amplifier amplifiers.
3-level MIC input, supports condenser microphone, dynamic microphone and
wireless microphone.
MIC port can support balance/unbalance signal, suppress the external noise
effectively.
Two stereo audio inputs and one digital audio input, switchable by button, IR remote
& RS232.
Volume/Bass/Treble controllable by buttons, IR remote & RS232.
Fast switching speed for good performance.
Convection cooler, fan is not needed.
LED indicator, for power and working status.
Antistatic case design to provide good protection for long-term and stable
performance.
1.3 Package Contents
1 x 40 Watt Power Amplifier
2 x Mounting ears (separated from 40 Watt Power Amplifier)
4 x Screws
1 x Pluggable Terminal Block
1 x RS232 cable
1 x Power adapter (DC 24V)

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1 x Power Cord
4 x Plastic Cushions
1 x User manual
Note: Ensure the product and the accessories are all included, if not, please contact
with the dealers.
2. Panel Description
2.1 Front Panel
Figure 1 Front Panel
No. Name Function
①Audio Input
Selection
To select the input audio source, after choosing the audio
source, the corresponding LED indicator will be on. No.1 is
for dual mono audio input (2 RCA connectors for L&R), No.2
is for stereo audio input (3.5mm mini jack), and No.3 is for
digital fiber audio input.
②Audio
Control
Adjust the volume of the MIC, Line, or the level of Bass and
Treble with this button
③Volume
Adjustment
To turn up/down or mute the corresponding audio.
▽
▽▽
▽: Turn down the volume
△
△△
△: Turn up the volume
MUTE: Mute the output

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2.2 Introduction of Rear Panel
Figure 2 Rear Panel
No. Name Function
①Power
Indicator Turns red when power on.
②Microphon
e input port
3-pole captive screw connector for microphone input, the dial
switch in right side is to select the micro input kind, including
48V (for condenser microphone), MIC (for dynamic
microphone) and LINE (for line audio).
③Audio
Inputs
3.5mm mini jack for stereo audio input, it can be connected
with audio source device such as DVD player.
④ID Code 16 codes range from 0 to F (hexadecimal), works together with
the PC control software.
⑤IR To connect with the IR receiver, works together with the IR
remote.
⑥Power Port To connect with the power adapter (DC24V).
⑦2 x RCA Dual-mono audio input, which can be connected with audio
source device such as a PC.
⑧Digital
Audio Input
Fiber connector for digital audio input (PCM format only), it can
be connected with a device with fiber port, such as blue-ray
player.
⑨RS232
3-pole captive screw connector for serial control, it can be
connected with PC (Use a 3-pole captive to 9 pin female D
connector and serial control software) to control 40 Watt Power
Amplifier.
⑩Audio
Output
To connect with audio output devices, such as speakers (To
select 70V or 100V depends on the input voltage of the
speakers). COM is for grounding (GND).

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3. System Connection
3.1 Usage Precautions
1) No working with empty load is allowed.
2) Speakers must be connected before power on.
3.2 System Diagram
Figure 3 System Diagram
3.3 Audio Signal Connection
3.3.1 Audio Output
40 Watt Power Amplifier supports mono audio output, and the output voltage is 70V or
alterative 100V. With its dual-purpose design, it can be applied in different areas. The
end COM is for grounding. The amplifier to be connected is mono audio output with a
rated power at 40Watt, so 40 Watt Power Amplifier can be connected with several
speakers in parallel connection way (Total power mustn’t be more than 40Watt).
The following figure shows us how to connect with the speakers. Here we take the
100V/10W speakers for each as example.
MIC
PC 1
Blu-ray
DVD
Speaker
Speaker
Speaker
Speaker
PC
(100V/10W)
(100V/10W)
(100V/10W)
(100V/10W)
IR Remote
IR Receiver

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Figure 4 Audio Output Connection
Note: Speakers to be connected should be with constant pressure.
3.3.2 Audio Inputs
40 Watt Power Amplifier provides with 2 stereo audio inputs, one microphone input and
one digital fiber audio input. The following figure shows the audio input ports.
Figure 5 Audio Input Ports
48V phantom power input
When the switch turns to “48V” (It has a good frequency characteristic, high input
impedance and high sensitivity in this mode), the MIC input will provide a 48V phantom
power. This is usually used for power supply for condenser microphone, Connection is:
“+” connects to positive, “-” connects to negative and “ ” to ground.
Note: In this mode, only condenser microphone can be connected with.
MIC input
When the switch turns to “MIC” (It has a low frequency characteristics, and wide
frequency response in this mode), the microphone input is used for connecting with
dynamic microphone. There are two different connections:
a) Unbalanced connection:
“+” and “ ” connect to ground, and “-” connects to signal.
COM
70V
100V
Speaker
Speaker
Speaker
Speaker
(100V/10W)
(100V/10W)
(100V/10W)
(100V/10W)
Dial Switch, to select the MIC input mode,
includes MIC (dynamic microphone), 48V
(condenser microphone) and LINE
(normal audio or wireless microphone).

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“-” and “ ” connect to ground, and “+” connects to signal.
b) Balanced connection: “+” connects to positive, “-” connects to negative and “ ”
connects to ground.
LINE input
When the switch turns to “LINE” (It has a low frequency characteristics, and wide
frequency response in this mode), the microphone input is used for connecting with
normal audio or wireless microphone output. There are two different connections:
a) Unbalanced connection:
“+” and “ ” connect to ground, and “-” connects to signal.
“-” and “ ” connect to ground, and “+” connects to signal.
b) Balanced connection: “+” connects to positive, “-” connects to negative and “ ”
connects to ground.
Digital Audio Input
40 Watt Power Amplifier provides with a fiber optical port to connect with digital audio
source device. With the SPF optical fiber, the audio signal can be transmitted faster,
more stable, reliable, and can be transmitted over a long distance without distortion.
Notice: This digital audio input can support/decode PCM format signal only. If the
CD/DVD is DTS or AC3 format, please set the player to PCM format output before
connect to 40 Watt Power Amplifier.
3.4 System Applications
40 Watt Power Amplifier can be applied in different occasions, such as classroom,
small meeting room, lecture hall, bar and hotel etc.
4. System Operations
4.1 Operations of Front Panel
The buttons provides the control of volume/EQ control and switching. The LED
indicator will show the connecting status. The following content introduces audio
switching and EQ control in detail.
Operations: Press the corresponding button again for cyclic switching.
4.1.1 Audio switching
There are three switchable audio inputs, one 2xRCA input, one 3.5mm jack input, and
one digital fiber audio input, switchable through the buttons as below:
Figure 6 Audio Source Selection Button
Audio Source Selection:
1: Dual mono audio
2: Stereo audio
3: Digital fiber audio.

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4.1.2 Volume/EQ controlling
The line volume and MIC volume can be controlled by the buttons.
The MIC Volume/LINE volume/LINE bass/LINE treble will be selected by the buttons,
and controlled up/down/mute by the function buttons. Please check the picture below:
Figure 7 Audio Mode and Volume Adjustment buttons
For example, to turn up the line volume, you should select the “LINE” first, and then
press the button “ ”.
4.2 Operations of IR Remote
40 Watt Power Amplifier provides with an IR eye, with the IR Receiver and the IR
remote, user can control 40 Watt Power Amplifier remotely.
Notice: The IR Receiver and the IR remote are all offered for charge.
Figure 8 IR Remote
Audio Mode Switching
Volume Adjustment:
▽
▽▽
▽: Turn down the volume
△
△△
△: Turn up the volume
MUTE: Mute the output
Mute Mode:
MIC: Mute the
microphone volume.
LINE: Mute the line
volume.
SPEAKER: Unmute
Use to transmit the
infrared signal send by
the remote controller.
Audio Controlling Modes
MIC: turn up/down the
microphone volume.
LINE: turn up/down the line
volume.
BASS: bass tuning
TREBLE: treble of line
volume.
Audio Source Selection:
1:2 RCA dual-mono audio
input
2:1 3.5mm jack
3: 1 Digital fiber audio input

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Figure 9 IR Receiver
4.3 Operations of Control Software
4.3.1 Connection with Computer
When the amplifier connects to the COM1 or COM2 of the computer with control
software, users can control it by that computer.
To control the amplifier, users should use a 3-pole male captive screw to 9-pin HD
female connector and use the public COM software.
Figure 10 Connection of RS232 Port
4.3.2 Installation/uninstallation of RS232 Control Software
Installation
Connect the input source devices and the output device according to the system
diagram.
Copy the RS232 control software to one computer, and then connect the RS232
port of this computer and 40 Watt Power Amplifier.
Double-click the EXE program to execute the software.
Here we take the software CommWatch.exe as example. The icon is showed as
below:
Figure 11 Control Software
IR receiver, works together
with the IR remote. Please
point the IR remote at the IR
receiver when use, to avoid
getting out of control as there
is no signal detected.
3.5mm jack
Insert it into the
specialized PA3
socket (3.5mm), to
connect the IR
receiver with PA3.

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Uninstallation Delete all the control software files in corresponding file path.

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4.3.3 Running Environment
While the control software is installed, we can activate the software through the RS232
port and set the parameters, to make it able to send RS232 commands to control 40
Watt Power Amplifier.
4.3.4 Function Settings
With the control software, we can easily switch the input channel, mute the output,
check the working status, and adjust the volume etc. Please refer the details in RS232
Communication Commands.
The interface of the control software is showed as below:
Figure 12 Main Interface of Control Software
Parameter Configuration area
Monitoring area, indicates if
the command sent works.
Command Sending area

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4.3.5 RS232 Communication Commands
Communication Protocol: RS232 Communication Protocol
Baud rate: 9600 Data bit: 8 Stop bit: 1 Parity bit: none
Command Function Description Feedback Code
1A1. Switching the audio to input 1 A: 1 -> 1
2A1. Switching the audio to input 2 A: 2 -> 1
3A1. Switching the audio to input 3 A: 3 -> 1
0A0. Mute Audio of MIC and Line out Mute
1A0. Mute audio of MIC Mute MIC
2A0. Mute audio of line out Mute LIN
3A0. Enable noise gate. Gate On
4A0. Disable noise gate. Gate Off
0A1. Unmute Audio Unmute Audio
600% Checking the working status
A: 1 -> 1
Volume of MIC : 50
Volume of LINE : 50
Bass of LINE : 4
Treble of LINE : 4
Ducking Off
601% MIC volume up Volume of MIC: 51
602% MIC volume down Volume of MIC: 51
603% Line volume up Volume of LINE: 51
604% Line volume down Volume of LINE: 51
605% Bass level up Bass of LINE: 4
606% Bass level down Bass of LINE: 4
607% Treble level up Treble of LINE: 4
608% Treble level down Treble of LINE: 4
609% Initialization, back to the default setting Init OK
610% Enable/disable the ducking function. Ducking off/Ducking on
4[x][x]%
Preset the volume level of ducking
function. [xx] arranges from [00] to [60].
61 degrees in total.
Ducking of LINE: 50
5[x][x]% Preset MIC volume, [xx] arranges from
[00] to [60]. 61 degrees in total. Volume of MIC: 50
7[x][x]% Preset line volume, [xx] arranges from
[00] to [60]. 61 degrees in total. Volume of LINE: 50
8[x][x]% Preset the bass level, [xx] arranges from
[00] to [08]. 9 degrees in total. Bass of LINE: 4
9[x][x]% Preset the treble level, [xx] arranges from
[00] to [08]. 9 degrees in total. Treble of LINE: 4

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Notice:
1. The letter inside bracket [ ] is the variable code, which is changeable.
2. The bracket [ ] is not included to the RS232 commands.
3. Any dot “.” after the letters is part of the commands.
4. Ducking function:
When input with MIC, the volume of the line audio will be automatically turned down
to the preset volume level, if there is no input MIC audio signal after 5 seconds,
then the volume will be automatically turned up to the original one. If you need to
disable/enable the ducking function, just send the command “610%” again.
5. ID coding
The ID codes of 40 Watt Power Amplifier ranges from 0 to F (hexadecimal), when
sending RS232 commands, please take notice of the address of the ID code.
If the address of the ID code is 0, any RS232 command is available.
If the address is in 1~F, it has one unique ID code (If the ID code is not the same
with the address, no RS232 command will work).
While the ID code is in 1~F, please add “ID/” before sending the command.
For example, if the ID code is 5, the RS232 command needed is “604%”, the
correct command is in this format: 5/604%.
There is no need to add “ID/” before the command when the ID code is 0.
Examples:
1) Switching the input 2 to the line out, the command is: 2A1.
2) Turning up the volume of line audio, the command is: 603%
3) Preset the MIC volume to “21” degree, the command is: 521%
4) Checking the working status of 40 Watt Power Amplifier, the command is: 600%
5) If the ID code is 0, sending command 601% is able to turn up the MIC volume.
If the ID code is 2, sending command 601% will not work, and the MIC volume
remains unchanged. The right command is 2/601%.

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5. Specifications
Audio Input Audio Output
Input
2stereo audio
1MIC
1Digital fiber audio
Output 1mono amplifier
Input
Connector
2RCA
13.5mm jack
13-pole 3.81mm
captive screw
connector
1SPF fiber connector
Output
Connector
13-pole 3.81mm
captive screw
connector
Input
Impedance >10KΩOutput Type Constant voltage 70V or 100V.
Audio General
Frequency
Response 120Hz ~ 20KHz CMRR >70dB@20Hz~20KHz
SNR 80dB (Max) Bandwidth 120Hz ~ 20KHz
Rated Power
Output 40Watt @8Ohms THD + Noise
1%@1KHz,
0.3%@20KHz at
nominal level
Voltage Gain 26dB
Control Function
RS232 Control
13-pole 3.81mm
captive screw
connector
Front Panel
Control buttons
ID Code
Control 16 ID codes for control.
Optional IR remote & TCP/IP controlled by PTNET(PTN's programmable
interface)
General
Temperature -10 ~ +40℃Humidity 10% ~ 90%
Power
Supply
DC 24V power
adapter
Standby
Power
Consumption
5W
Case
Dimension
W130 x H44 x
D144mm (1U high)
Product
Weight 0.86Kg

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6. Panel Drawing
Figure 13 Panel Drawing

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7. Troubleshooting and Maintenance
Problems Causes Solutions
No output audio
No signal at input/ output
end
Check input/ output signal
by an oscilloscope or a
multimeter.
Failed cable connection Change for another cable.
Broken unit Send it to the dealer for
repairing.
POWER indicator doesn’t
work or no respond to any
operation
Failed power connection Make sure the power cord
connection is good
Static becomes stronger
when connecting the
video connectors Bad grounding
Check the grounding and
make sure it is connected
well.
Output audio is interfered
Cannot control the device
by front panel buttons,
RS232 port or IR remote
Broken unit Send it to the dealer for
repairing.
If your problem persists after following the above troubleshooting steps, seek further
help from authorized dealer or our technical support.

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8. After-sales Service
1) If there appear some problems when running 40 Watt Power Amplifier, please check
and deal with the problems reference to this user manual. Any transport costs are
borne by the users during the warranty.
2) You can email to our after-sales department or make a call, please tell us the
following information about your cases.
Product version and name.
Detailed failure situations.
The formation of the cases.
3) We offer products for all three-year warranty, which starts from the first day you buy
this product (The purchase invoice shall prevail).
4) Any problem is same with one of the following cases listed, we will not offer
warranty service but offer for charge.
Beyond the warranty.
Damage due to incorrectly usage, keeping or repairing.
Damage due to device assembly operations by the maintenance company non-
assigned.
No certificate or invoice as the proof of warranty.
The product model showed on the warranty card does not match with the model
of the product for repairing or had been altered.
Damage caused by force majeure.
Remarks: For any questions or problems, please try to get help from your local
distributor.