BZBGEAR BG-AMP2X20 User guide

BG-AMP2X20

Mini Digital Amplifier

All Rights Reserved

User Manual

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. The
functions described in this version are updated till March 2015. Any changes of
functions and parameters since then will be informed separately. Please refer to the
dealers for the latest details.

Trademarks

Product model and its 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 our 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.

SAFETY PRECAUTIONS

To ensure 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.

Table of Contents

1. Introduction ............................................................................................. 1

1.1. Introduction to BG-AMP2X20 Mini Digital Amplifier........................ 1

1.2. Features ......................................................................................... 1

1.3. Package List ................................................................................... 1

2. System Connection Introduction ............................................................. 2

2.1. Audio Output .................................................................................. 2

2.1.1. Default output: 2x20Watt@4Ohm ....................................... 2

2.1.2. Bridge connection: 1x40Watt@8Ohm ................................. 2

2.1.3. Dual-mono Output ............................................................... 3

2.2. Microphone input ............................................................................ 3

2.2.1. 48V phantom power input ................................................... 3

2.2.2. MIC input ............................................................................. 3

2.2.3. LINE input ........................................................................... 3

3. Operation of the Control Panel and the IR Remote ................................ 4

3.1. Operation of the Control Panel ....................................................... 4

3.1.1. Audio switching ................................................................... 4

3.1.2. Volume/EQ controlling ........................................................ 4

3.2. Usage of the IR Remote ................................................................. 5

4. System Diagram ..................................................................................... 6

5. Communication Protocol and Command Codes ..................................... 7

6. Specification ........................................................................................... 8

7. Panel Drawing ........................................................................................ 9

8. Troubleshooting & Maintenance ........................................................... 10

9. After-sales Service ................................................................................ 11

10. Warranty Information (Second Year Assurance) ................................... 12

11. Mission Statement ................................................................................ 13

1

Introduction

1.1. Introduction to BG-AMP2X20 Mini Digital Amplifier

The BG-AMP2X20 Mini Digital Amplifier is a compact-size digital amplifier (Class-D)
with 3 inputs (2 line in and 1 balanced MIC). It is integrated with powerful functions,
including bridge connection, dual-mono, EQ control, microphone mixer etc.

It has a good application in different places, including classroom, small meeting room,
lecture hall, bar, pub etc.

1.2. Features

2x20Watt@4Ohm as the default amplifier output.
Bridge connection function. User can switch the Mini Digital Amplifier to be

1x40Watt@8Ohm by bridge connection.
Two stereo audio inputs, switchable by button, IR remote & RS232.
Volume/Bass/Treble controllable by buttons IR remote & RS232.
MIC port can support balance/unbalance signal, suppress the external noise

effectively.
Line audio output at 3.5mm jack, with volume controllable.
Dual-mono function. User can sum up the stereo audio to two times mono audio.
MIC mixer function. The microphone will be mixed to the line audio output, and be

controlled separately.
MIC input supports 48V phantom power, dynamic MIC and wireless MIC.
Auto noise gate. It keeps detecting the audio and MIC input, will mute the output

when there is no input.
Ultra low inrush current, no need for power sequencing. This allows multiple Mini

Digital Amplifier to be powered on simultaneously without overloading power

circuits.
Convection cooler, fan is not needed.
Antistatic case design: providing good protection for long-term and stable

performance.

1.3. Package List

1 x BG-AMP2X20 Mini Digital Amplifier (The mounting ears and Mini Digital

Amplifier are as a whole.)

2 x Pluggable Terminal Blocks
1 x RS232 Cable
1 x Power Adapter

2

1 x Power Cord
4 x Plastic Cushions
1 x User Manual

Notes：

The IR remote and its battery are offered for charge separately.
The IR receiver is also offered for charge.
Please confirm if the product and the accessories are all included, if not, please

contact with the dealers.

System Connection Introduction

2.1. Audio Output

2.1.1. Default output: 2x20Watt@4Ohm

The default output of amplifier is 2x20Watt@4Ohm, so user can connect the amplifier
output in the regular way. As the picture below:

2.1.2. Bridge connection: 1x40Watt@8Ohm

The Mini Digital Amplifier has the bridge connection, to double the output power at
1x40Watt@8Ohm. It will sum up the input left channel and input right channel to be
mono output, and the power is up to 40Watt.
The bridge connection is:

Connecting the two pins, like this

Connecting the four pins, like this

3

2.1.3. Dual-mono Output

The Mini Digital Amplifier also has the function of double-mono output. It can sum up
the left and right channel, to be the mono audio output. In this way, the both of the
outputs are showing the same mono audio.
The connection is:

2.2. Microphone input

The microphone input of Mini Digital Amplifier has three modes, and different modes
use different connections, as the picture below:

2.2.1. 48V phantom power input

When the switch turns to “48V”, 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.

2.2.2. MIC input

When the switch turns to “MIC”, the microphone input is used for connecting with

dynamic microphone. There are two different connections:

1) Unbalanced connection:

“╧” connects to ground, and “-” connects to signal.
“╧” connects to ground, and “+” connects to signal.

2) Balanced connection: “+” connects to positive, “-” connects to negative and “╧”
connects to ground.

2.2.3. LINE input

When the switch turns to “LINE”, the microphone input is used for connecting with

normal audio or wireless microphone output. There are two different connections:

Connecting the four pins, like this

4

1) Unbalanced connection:

“╧” connects to ground, and “-” connects to signal.
“╧” connects to ground, and “+” connects to signal.

2) Balanced connection: “+” connects to positive, “-” connects to negative and “╧”
connects to ground.

Operation of the Control Panel and the IR Remote

3.1. Operation of the Control Panel

The buttons provide the control of volume/EQ control and switching. The following
content introduces audio switching and EQ control in detail.

3.1.1. Audio switching

There are two switchable stereo audio inputs, one 2xRCA input, and one 3.5mm jack
input, switchable through the buttons as below:

3.1.2. 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:

Source

Selection

5

For example, to turn up the line volume, you should select the “LINE” first, and then
press the button “ ”.

3.2. Usage of the IR Remote

Mute Mode:
MIC: Mute the

microphone volume.
LINE: Mute the line

volume.
SPEAKER: Unmute

Use to transmit the
infrared signal send by
the IR remote.

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 Inputs

1: RCA dual-mono audio inputs
2: 3.5mm jack

Firstly to
select the
function
from this
menu.

Then to turn
down/up the
level, or
mute the
output.

6

Notice: The IR remote, the IR receiver, and the battery of the IR remote are all offered

for charge.

System Diagram

IR receiver head, works in
conjunction 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 socket
(3.5mm) to connect
the IR receiver with
the amplifier

7

Communication Protocol and Command Codes

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

0A0.

Mute Audio of MIC and Line out

Mute

1A0.

Mute audio of MIC

Mute MIC

2A0.

Mute audio of line out

Mute LIN

0A1.

Unmute Audio

Unmute

3A0.

Switch on Noise Gate

Gate On

4A0.

Switch off Noise Gate

Gate Off

600%

Checking the working status

A: 1 -> 1
Volume: 30
Bass: 00
Treble: 00

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: 04

606%

Bass level down

Bass of LINE: 04

607%

Treble level up

Treble of LINE: 04

608%

Treble level down

Treble of LINE: 04

609%

Initialization, back to the default
setting

Init OK

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: 04

9[x][x]%

Preset the treble level, [xx] arranges
from [00] to [08].
9 degrees in total.

Treble of LINE: 04

Notice:

1: The letter inside bracket [ ] is the variable code, which is changeable.

8

2: The bracket [ ] is not included to the RS232 commands.
3: Any dot “.” after the letters is part of the commands.

Example 1:
Switching the input 2 to the line out, RS232 command is: [2A1.]
Example 2:
Turning up the volume of line audio, RS232 command is: [603%]
Example 3:
Preset the MIC volume to “21” degree, RS232 command is: [521%]
Example 4:

Checking the working status of Mini Digital Amplifier, RS232 command is: [600%]

Specification

Audio Input

Audio Output

Input

2 stereo audio,
1 MIC

Output

1 amplifier,
1 stereo audio

Input
Connector

2 RCA
1 3.5mm jack
1 pluggable terminal
block (3P,3.81mm),

Output
Connector

1 3.5mm jack
1 pluggable terminal
block (4P, 5.08mm)

Input
Impedance

>10KΩ

Output
Impedance

50Ω/stereo,
4~8Ω/Amplifier

Audio General

Frequency
Response

20Hz ~ 20KHz

CMRR

>70dB@20Hz~20KH
z

SNR

80dB at maximum
output

Bandwidth

20Hz ~ 25KHz

Stereo
Channel
Separation

>75dB@20Hz to
20KHz

THD + Noise

1%@1KHz,

0.3%@20KHz
at nominal level

Voltage Gain

32dB

Power Output

2x20 Watts (4 Ohms)

Control Function

RS232 Control

3-hole phoenix
connector

Panel Control

Optional button
control

IR Remote

Optional IR remote

9

Panel Drawing

10

Troubleshooting & Maintenance

1) When there is no output audio:

Check if there is any signal at the input.
Check if there is any signal at the output.

We can check these by using an oscilloscope or a multimeter. If there is no
signal input/output, maybe the input/output cables broken or the connectors
loosen, please change for another cable.

Check if the output port number is the same with the controlled one.
If not the problem mentioned above, probably there is something broken inside

the unit, please send it to the dealer for repairing.

2) If the POWER indicator doesn’t work or no respond to any operation, please make
sure the power cord connection is good.

3) If the output sound is interfered, please make sure the system is grounded well.

4) If the static becomes stronger when connecting the audio connectors, it probably

due to bad grounding, please check the grounding and make sure it connected
well, otherwise it would damage the converter.

5) If the Mini Digital Amplifier amplifier cannot be controlled by the keys on the front
panel, RS232 port or IR remote, the unit may have already been broken. Please
send it to the dealer for repairing.

11

After-sales Service

If there appear some problems when running the device, please check and deal with
the problems referring to this user manual.

1) Product Limited Warranty: We warrant that our products will be free from defects
in materials and workmanship for one year, which starts from the first day you buy
this product (The purchase invoice shall prevail).
Proof of purchase in the form of a bill of sale or receipted invoice which is evidence
that the unit is within the Warranty period must be presented to obtain warranty
service.

2) What the warranty does not cover (servicing available for a fee):

Warranty expiration.
Factory applied serial number has been altered or removed from the product.
Damage, deterioration or malfunction caused by:

Normal wear and tear
Use of supplies or parts not meeting our specifications
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.
Servicing not authorized
Any other causes which does not relate to a product defect

Delivery, installation or labor charges for installation or setup of the product

3) Technical Support: Email to our after-sales department or make a call, please
inform us the following information about your cases.

Product version and name.
Detailed failure situations.
The formation of the cases.

Remarks: For any questions or problems, please try to get help from your local
distributor.

Warranty Information (Second Year Assurance)

Second Year Assurance

BZBGEAR wants to assure you peace of mind. We're so confident in the quality of

our products that along with the manufacturer's one-year limited warranty, we are
offering free second-year warranty coverage upon registration*!

Taking advantage of this program is simple, just follow the steps below:

1. Register your product within 90 days of purchase by visiting

BZBGEAR.com/warranty.

2. Complete the registration form. Provide all necessary proof of purchase details,

including serial number and a copy of your sales receipt.

For questions, please call 1.888.660.2962 or email [email protected].

For complete warranty information, please visit BZBGEAR.com/warranty or scan the
QR code below.

*Terms and conditions apply. Registration is required.

Mission Statement

BZBGEAR manifests from the competitive nature of the audiovisual industry to

innovate while keeping the customer in mind. AV solutions can cost a pretty penny,
and new technology only adds to it. We believe everyone deserves to see, hear, and
feel the advancements made in today’s AV world without having to break the bank.

BZBGEAR is the solution for small to medium-sized applications requiring the latest

professional products in AV.

We live in a DIY era where resources are abundant on the internet. With that in mind,
our team offers system design consultation and expert tech support seven days a
week for the products in our BZBGEAR catalog. You’ll notice comparably lower
prices with BZBGEAR solutions, but the quality of the products is on par with the top
brands in the industry. The unparalleled support from our team is our way of showing

we care for every one of our customers. Whether you’re an integrator, home theater

enthusiast, or a do-it-yourselfer, BZBGEAR offers the solutions to allow you to focus
on your project and not your budget.