Milestone MP-A250B User manual

MP-A250B
Mini Audio Amplifier
All Rights Reserved
Version: MP-A250B_2016V1.0
User Manual

Mini Audio Amplifier
Preface
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.
Trademarks
Product model and logo are trademarks.Any other trademarks mentioned in this manual
are acknowledged as the properties of the trademark owner. No part of this publication
may be copied or reproduced without prior written consent.
FCC Statement
This equipment generates, uses and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions, may cause harmful interference
to radio communications. It has been tested and found to comply with the limits for a
Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed
to provide reasonable protection against harmful interference in a commercial
installation.
Operation of this equipment in a residential area is likely to cause interference, in which
case the user at their own expense will be required to take whatever measures may be
necessary to correct the interference
Any changes or modifications not expressly approved by the manufacture would void
the user’s authority to operate the equipment.

Mini Audio Amplifier
SAFETY PRECAUTIONS
To insure the best from the product, please read all instructions carefully before using
the device. Save this manual for further reference.
Unpack the equipment carefully and save the original box and packing material for
possible future shipment
Follow basic safety precautions to reduce the risk of fire, electrical shock and injury
to persons.
Do not dismantle the housing or modify the module. It may result in electrical shock
or burn.
Using supplies or parts not meeting the products’ specifications may cause damage,
deterioration or malfunction.
Refer all servicing to qualified service personnel.
To prevent fire or shock hazard, do not expose the unit to rain, moisture or install this
product near water.
Do not put any heavy items on the extension cable in case of extrusion.
Do not remove the housing of the device as opening or removing housing may
expose you to dangerous voltage or other hazards.
Install the device in a place with fine ventilation to avoid damage caused by
overheat.
Keep the module away from liquids.
Spillage into the housing may result in fire, electrical shock, or equipment damage. If
an object or liquid falls or spills on to the housing, unplug the module immediately.
Do not twist or pull by force ends of the optical cable. It can cause malfunction.
Do not use liquid or aerosol cleaners to clean this unit. Always unplug the power to
the device before cleaning.
Unplug the power cord when left unused for a long period of time.
Information on disposal for scrapped devices: do not burn or mix with general
household waste, please treat them as normal electrical wastes.

Mini Audio Amplifier
Contents
1. Introduction...............................................................................................................1
1.1 Introduction to MP-A250B ................................................................................1
1.2 Features ............................................................................................................1
1.3 Package List......................................................................................................1
2. Panel Description .....................................................................................................2
2.1 Front Panel........................................................................................................2
2.2 Rear Panel.........................................................................................................3
3. System Connection ..................................................................................................4
3.1 Usage Precautions............................................................................................4
3.2 System Diagram................................................................................................4
3.3 Connection Procedure.......................................................................................4
3.4 Audio Output Connection...................................................................................5
3.4.1 Stereo output (default): 2x50Watt@8Ohm...............................................5
3.4.2 Mono output: 1x100Watt@4Ohm ............................................................5
3.5 Loop Connection ...............................................................................................6
3.6 Application.........................................................................................................6
4. System Control .........................................................................................................7
4.1 Front Panel Button Control................................................................................7
4.2 IR Control ..........................................................................................................8
4.3 RS232 Control...................................................................................................9
4.3.1 Installation/uninstallation of RS232 Control Software..............................9
4.3.2 Basic Settings..........................................................................................9
4.3.3 RS232 Communication Commands ......................................................11
4.4 TCP/IP Control.................................................................................................12
4.4.1 Control Modes.......................................................................................12
4.4.2 Control via TCP/IP communication software .........................................13
4.4.3 Control via web-based GUI....................................................................14
4.4.4 Port Management..................................................................................16
5. Specification ...........................................................................................................17
6. Panel Drawing.........................................................................................................18
7. Troubleshooting & Maintenance ...........................................................................19
8. After-sales Service..................................................................................................20

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1. Introduction
1.1 Introduction to MP-A250B
MP-A250B is a compact-size digital amplifier (Class-D) with 3 inputs (1 L+R stereo
audio, 1 analog audio, 1 optical fiber audio). It features switchable stereo or mono
output, and boasts complete EQ adjustment and intuitive work status display, making it
an ideal addition to a classroom or conference room application.
1.2 Features
3 audio inputs: 1 L+R stereo, 1 analog, 1 optical fiber
Switchable stereo / mono output
Complete EQ management: including LINE, BASS, TREBLE
Easy volume adjustment via a rotary knob
Audio loop output
Intuitive LED indicators for input source, control and volume setting
Controllable via RS232, IR, TCP/IP (optional)
Web-based GUI
Power off memory
1.3 Package List
1 x MP-A250B
2 x Detachable Mounting Ears
4 x Screws
2 x Pluggable Terminal Blocks (1 3-pin& 1 4-pin)
1 x IR Remote
1 x Power Adapter (DC 33V 4A)
1 x User manual
1 x IR Receiver (5V, without carrier)
Please confirm if the product and the accessories are all included, if not, please
contact with the dealers.

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2. Panel Description
2.1 Front Panel
Figure 2- 1 Front Panel of MP-A250B
No.
Name
Description
①
Power LED
Illuminate red when powered on
②
Input Selection
Press to select any one of the 3 inputs, indicators will light
accordingly
Input 1~3 corresponds to audio sources connected to the 3
audio input ports separately;
1: L+R stereo audio
2: 3.5mm analog audio
3: optical audio
③
Control
Press to select the audio to be controlled, including LINE,
BASS, TREBLE
④
Volume Knob
Press to mute/unmute the audio
Note: after pressed the button to mute the audio, except
pressing it again to restore the audio at the same volume,
users can rotate the knob to enable audio output at
respective volume.
Rotate the knob to adjust volume, volume bars will change
accordingly
Clockwise Rotation: Volume up
Anticlockwise Rotation: Volume down
⑤
Volume Bars
Indicate real-time volume setting, 10 bars in total, no volume
bar will be lighted when the audio is muted
Operation Format: “INPUT SEL”+ “CONTROL”+ “Volume Knob”
Example: To adjust bass audio of input 3, select input 3 -> choose bass -> adjust the
volume knob.
CONTROLINPUT SEL
1
2
3
LINE
BASS
VOLUME

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2.2 Rear Panel
Figure 2- 2 Rear Panel of MP-A250B
No.
Name
Description
①
CONTROL
TCP/IP: (optional) connect with control device to enable IP
control via web-based GUI& TCP/IP communication
software;
Indicators will blink when connected to control device
and communicated normally
RS232: connect with control device to enable serial control
IR IN: connect with IR receiver to collect infrade signal
Channel Switcher: dial to STEREO or MONO to enable
corresponding output mode
②
INPUTS
Audio inputs area, 3 audio inputs in total, including 1 stereo
audio, 1 analog audio and 1 optical audio
③
OUTPUTS
LOOP: analog audio loop output port, available only when input
signal is L+R stereo audio
Audio Output: including stereo audio (2x50W@8Ω), or mono
output (1x100W@4Ω)
④
DC 33V
Insert DC 33V 4A power adapter here
⑤
GND
Connect to grounding
Dial the Channel Switcher to demand status before connecting output device.
Once connected, do not try to change the status while it’s working.
LOOP
3
1
DC 33V
IR INRS232
Tx Rx
AUDIO OPTICALL R
2
TCP/IP 2x50W 8@ Ω
1x100W 4@
STEREO
MONO

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3. System Connection
3.1 Usage Precautions
1) System should be installed in a clean environment and has a prop temperature and
humidity.
2) All of the power switches, plugs, sockets and power cords should be insulated and
safety.
3) All devices should be connected before power on.
4) Use straight-thru Cat5e/Cat6 with TIA/EIA T568B terminations to connect TCP/IP
port.
3.2 System Diagram
Figure 3- 1 System Diagram
3.3 Connection Procedure
Step1.Connect audio sources (such as Blue-ray DVD) to INPUT ports of the device with
audio cables;
Step2.Dial the Channel Switcher to the right status, and connect audio output devices
(such as speakers) to audio output port accordingly (Specified in 3.4 Audio
Output Connection).
Step3.(optional) Insert an IR receiver (5V, without carrier) to IR IN to enable IR control.
Step4.(optional) Connect a control device (e.g. a PC) to RS232 port to enable serial
control.
Step5.(optional) Connect a control device (e.g. a PC) to TCP/IP port to enable IP
control.
Step6.Plug DC 33V power adaptor to the power port of MP-A250B.
Laptop
Speaker
MP-A250B
MP-A250B
IR Remote
IR Receiver
IR Signal:
AUDIO Signal:
Control Signal:
DVD

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3.4 Audio Output Connection
3.4.1 Stereo output (default): 2x50Watt@8Ohm
Dial the switcher to STEREO to enable 2 50Watt@8Ohm stereo output mode. Connect
the amplifier regularly (as shown in the following figure):
Figure 3- 2 Stereo Output Connection
3.4.2 Mono output: 1x100Watt@4Ohm
To enable mono 1x100Watt@4Ohm output, dial the switcher to MONO, and connect
output devices as the figure below:
Figure 3- 3 Mono Output Connection

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3.5 Loop Connection
MP-A250B boasts a LOOP port for audio signal loop output, max 255 units can be
looped within the same operation system. Connect MP-A250B like this:
Figure 3- 4 Loop Connection
Then audio signal sent to the first MP-A250B is cascaded to other connected MP-A250B,
which enables multiple MP-A250B share the same audio source.

1. Audio loop output is available only when the 1st MP-A250B select input 1/2 as
source.
2. Audio control operations are not available to looped audio signal.
3.6 Application
MP-A250B has a good application in various occasions, such as computer realm,
monitoring, big screen displaying, meeting room, education and bank & securities
institution etc.
Laptop
Speaker
MP-A250B
MP-A250B
Speaker
Speaker

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4. System Control
4.1 Front Panel Button Control
Front panel buttons provides direct audio control including input source selection and
audio effect adjustment.
Figure 4- 1 Front Panel Buttons
Operation Format: Input Sel + Control + Volume Knob (indicators and volume bar will
display real-time operation)
Input selection (area ①):
Press button INPUT SEL to switch among the 3 inputs cyclely, relative LED will
light to indicate real-time selection. There are 3 selectable audio sources,
corresponding to the 3 audio input ports on the rear panel separately.
1: L+R stereo audio
2: 3.5mm analog audio
3: optical audio
Control (EQ management) (area ②):
Including LINE, BASS and TREBLE, press button Control to switch among the 3
inputs circularly, relative LED will light to indicate real-time selection.
Volume Knob (area ③):
Clockwise Rotation: Volume up
Anticlockwise Rotation: Volume down
About the Volume Bar (area ④):
Volume bar indicates real-time volume setting, 10 bars in total, the higher the volume is,
the more bars will be illuminated. In different EQ control, volume bar tend to act
differently:
LINE: Line volume can be 0~60, one more volume bar will light when the volume is
turned up by 6.
BASS: bass volume can be 0~10
TREBLE: treble volume can be 0~10

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4.2 IR Control
Connect an IR receiver (5V, without carrier) to IR IN port on the rear panel, users are
able to control the amplifier by the included IR remote (see as below):
Figure 4- 2 IR Remote
Input Selection
Unmute
Mute
Volume Control
Including LINE, BASS
and TREBLE volume
adjustment

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4.3 RS232 Control
MP-A250B boasts a 3-pin pluggable terminal block for serial control. The definition of
its pins is listed in the table below.
No.
Pin
Function
1
N/u
Unused
2
Tx
Transmit
3
Rx
Receive
4
N/u
Unused
5
Gnd
Ground
6
N/u
Unused
7
N/u
Unused
8
N/u
Unused
9
N/u
Unused
Connect MP-A250B to the control device (e.g. a PC) with RS232 cable and set the
parameters in the right manner, the control device is capable to control MP-A250B via
designed software.
4.3.1 Installation/uninstallation of RS232 Control Software
Installation: Copy the control software file to the computer connected with
MP-A250B.
Uninstallation: Delete all the control software files in corresponding file path.
4.3.2 Basic Settings
Firstly, connect MP-A250B with an input device and an output device. Then, connect it
with a computer which is installed with RS232 control software. Double-click the
software icon to run this software.
Here we take the software CommWatch.exe as example. The icon is showed as below:
The interface of the control software is showed as below:

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Please set the parameters of COM number, bound rate, data bit, stop bit and the parity
bit correctly, only then will you be able to send command in Command Sending Area.
Parameter Configuration area
Monitoring area, indicates
whether the command
sent works.
Command Sending area
Parameter Configuration area
Monitoring area, indicates
whether the command
sent works.
Command Sending area

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4.3.3 RS232 Communication Commands

1) Case-sensitive.
2) “[“, “]”in the commands are only for easy recognition and not necessary in real
operations. Other symbols including “.”“%”are parts of the commands.
3) Feedbacks listed in the column “Feedback”are only for reference, feedbacks may
vary according to different operations.
Communication protocol: Baud rate: 9600; Data bit: 8; Stop bit: 1; Parity bit: none.
Command
Description
Feedback
1A1.
Switch to input 1
A: 1 -> 1
2A1.
Switch to input 2
A: 2 -> 1
3A1.
Switch to input 3
A: 3 -> 1
0A0.
Mute Audio Line out
Mute Audio
0A1.
Unmute Audio Line out
Unmute Audio
600%
Inquire present working status
A: 1 -> 1
Volume: 30
Bass: 0
Treble: 0
601%
Turn up Line volume by 1
Volume of LINE: 51
602%
Turn down Line volume by 1
Volume of LINE: 51
603%
Turn up Bass volume by 1
Bass of LINE: 4
604%
Turn down Bass volume by 1
Bass of LINE: 4
605%
Turn up Treble volume by 1
Treble of LINE: 4
606%
Turn down Treble volume by 1
Treble of LINE: 4
607%
Restore factory default
Factory Default
A: 1 -> 1
Volume: 45
Bass: 5
Treble: 5
610%
Turn up Line volume by 3
Volume of LINE: 54
620%
Turn down Line volume by 3
Volume of LINE: 51
61X%
Turn up Line volume by X
Volume of LINE: 54
62X%
Turn down Line volume by X
Volume of LINE: 54
7[x][x]%
Preset line volume, [xx] can be 00~60, 61
degrees in total.
Volume of LINE: 50
8[x][x]%
Preset the bass level, [xx] can be 00~10,
11 degrees in total.
Bass of LINE: 7

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4.4 TCP/IP Control
MP-A250B boasts option TCP/IP port for IP control.
Default settings: IP: 192.168.0.178; Subnet Mast: 255.255.255.0; Gateway: 192.168.0.1;
Serial Port: 4001.
IP& gateway can be changed as you need, Serial Port cannot be changed.
Connect the Ethernet port of control device and TCP/IP port of MP-A250B, and set
same network segment for the 2 devices, users are able to control the device via
web-based GUI or designed TCP/IP communication software.
4.4.1 Control Modes
MP-A250B can be controlled by PC without Ethernet access or PC(s) within a LAN.
Controlled by PC without Ethernet access
Connect a computer to the TCP/IP port of the MP-A250B, and set its network segment
to the same as the MP-A250B’s.
Controlled by PC(s) in LAN
Connect MP-A250B, a router and several PCs to setup a LAN (as shown in the following
figure). Set the network segment of MP-A250B to the same as the router’s, then PCs
within the LAN are able to control MP-A250B.
9[x][x]%
Preset the treble level, [xx] can be 00~10,
11 degrees in total.
Treble of LINE: 7
GetIP;
Get the IP of the device
IP: 192.168.0.178
Same network
segment as the
switcher

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Follow these steps to connect the devices:
Step1.Connect the TCP/IP port of the MP-A250B to Ethernet port of PC with
straight-thru CAT5e/6.
Step2.Set the PC’s network segment to the same as the MP-A250B’s.
Step3.Set the MP-A250B’s network segment to the same as the router.
Step4.Set the PC’s network segment to the original ones.
Step5.Connect the MP-A250B and PC(s) to the router. PC(s) within the LAN is able to
control the MP-A250B asynchronously.
4.4.2 Control via TCP/IP communication software
(Exampled by TCPUDP software)
1) Connect a computer and MP-A250B to the same network. Open the TCPUDP
software (or any other TCP/IP communication software) and create a connection,
enter the IP address and port of MP-A250B (default IP: 192.168.0.178, port:4001):

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2) After connect successfully, we can enter commands to control the MP-A250B , as
below:
4.4.3 Control via web-based GUI
MP-A250B provides with built-in GUI for convenient TCP/IP control. GUI allows users to
interact with MP-A250B through graphical icons and visual indicators.
Type 192.168.0.178 (default IP, changeable via GUI) in your browser, it will enter the
log-in interface shown as below:
Figure 4- 3 Log-in interface
GUI interfaces can be displayed in Chinese/ English, selectable by clicking 中文/
ENGLISH.
Here you will receive the
feedback when a command
is sent.
Enter your command here.
Commands are the same with RS232
commands listed in 4.3.3 RS232
Communication Commands

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Type the right name and password in relative column:
Name: admin; Password: admin (default setting, changeable via GUI)
Click LOGIN, it will show the audio selection interface as shown below:
Audio Selection:
Figure 4- 4 Network Control
In this interface, you can:
Select input
Mute/ Unmute
LINE/ BASS/ TREBLE control: drag the volume dot to turn down/ up the
corresponding volume
Switch to network configuration interface by clicking NETWORK
Network Configuration:

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Figure 4- 5 Audio Selection
In this interface, you can:
Configure network settings:
IP: support DHCP and Static IP, choose demanded state by clicking the button
DHCP: IPAddress, subnet mask and gateway are fixed in this mode.
Static IP: set IPAddress, subnet mask and gateway manually. Make sure the
IP is different with control device’s.
Modify password: type in new password in the column, max at 5 numbers/
letters
Inquire software version
Switch to audio selection interface by clicking AUDIO SEL
If there is any modification in this interface, press Save to restore the settings, or
press Cancel to withdraw. Click ADUIO SEL to return to NETWORK interface.
Clear the cache of the browser beforehand to ensure reliable GUI operation.
4.4.4 Port Management
Type the designed website 192.168.0.178:100 (Default, changeable via GUI) in your
browser. Enter correct username and password (same with GUI name and password) to
log in the WebServer:
Here is the main configuration interface of the WebServer:
In this interface, you can:
Change website display language
Modify network settings: Go to Internet Settings -> WAN
Upgrade TCP/IP module: Go to Administration -> Upload Program -> Select
program file -> Start upgrading
Reboot the device after upgrading.