Fosi Audio DA-2120B User manual

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Fosi Audio DA-2120B User Manual

Product Specifications
Fosi Audio DA-2120B is a ultra mini Bluetooth 5.0 audio
amplifier for passive speakers that features stereo 100 watt
x2, 2 channel power amp which is equipped with integrated
Bluetooth, USB, coaxial, optical, 3.5mm aux and USB flash
disk inputs, with a remote control to switch volume, bass,
treble and modes to enjoy hi-res music!
THD:
SNR:
Bluetooth:
Max Power Output:
Bluetooth Transmission
Distance:
Input Mode:
≤ 0.001%
DA-2120B
≥ 92dB
Bluetooth Name:
Up to 50ft
Remote Control Distance: Up to 20ft
Power Supply: 24V 4.5A
100W + 100W @4Ω
Terminating Impedance: 2-8Ω
(Recommended 4Ω)
Bluetooth + USB + coaxial
+ optical + 3.5mm aux
+ USB flash disk
USB Input Sampling
Frequency:
16Bit/48kHz
Output Mode: Passive Speakers
Optical/Coaxial Input
Sampling Frequency:
32Bit/192kHz
Maximum USB flash
drive storage:
32GB
Frequency Range: 15Hz - 20kHz
Working Voltage: 12V - 24V
V5.0

Product Overview & Control
Functions
System Supported: XP/W7/W8/W10/MAC/Linux
Size: L140*W110*H34mm
(5.5*4.3*1.3inch)
Bluetooth Antenna
LED Display
Power Switch
Multi-function Knob:
Short press to switch modes;
Turn the knob to adjust the volume
AUX Input
Coaxial
Input
USB Flash
Drive Input
PC-USB Input
Speakers Output:
Only support passive speakers
Antenna
Interface Optical
Input DC Input:
Max 24V
BT
R L
PC OPTU-DISK
INPUTS
AUX COA DC IN

DA-2120B V- V+MODE

Remote Control
3
2
1
5
9
6
4
7
8
13
12
16
11
15
10
V– V+
MODE
H–
B–
H+
B+
14
Mute on/off3
Software volume5
Treble up6
Power on/off1
Play mode:
single cycle---
all loop---
file loop---
random play---
Note: It can only be used in USB flash
2
Number Function
Software volume down
(Note: For hardware sound, please adjust the
volume knob of the device.)
4

Package Contents
Fosi Audio DA-2120B *1
Remote Control *1
Optical Cable *1
PC-USB Cable *1
3.5mm to RCA Cable *1
Bluetooth Antenna *1
DC 24V Power Supply *1
User Manual *1
Banana Plugs *8
Quick Setup
Preparation
Prepare 1: DA-2120B, 24V power supply, passive speakers, speaker
wires, and banana plugs;
Prepare 2: Connect the DA-2120B to the passive speakers via the
speaker wire or banana plugs;
Prepare 3: Connect the 24V power supply to the DC input;
Prepare 4: Short press the Power Switch to turn on the DA-2120B
amplifier.
Treble down7
Bass down8
Bass up9
Input mode select10
Previous song11
Next song12
Play/Pause13
Rewinds song15
Fast forwards song16
Number keys: Allows direct access to
specific songs
14

Package Contents
Fosi Audio DA-2120B *1
Remote Control *1
Optical Cable *1
PC-USB Cable *1
3.5mm to RCA Cable *1
Bluetooth Antenna *1
DC 24V Power Supply *1
User Manual *1
Banana Plugs *8
Quick Setup
Preparation
Prepare 1: DA-2120B, 24V power supply, passive speakers, speaker
wires, and banana plugs;
Prepare 2: Connect the DA-2120B to the passive speakers via the
speaker wire or banana plugs;
Prepare 3: Connect the 24V power supply to the DC input;
Prepare 4: Short press the Power Switch to turn on the DA-2120B
amplifier.
Method 2: Bare wire connection illustration
: Release the horn terminals block terminals;
: Insert the two ends of the speaker wire into the
amplifier and speaker terminal holes;
: Tighten the horn terminals;
Note: Please make sure that the speakers’ wire are not attached
with each other, the speaker connection area is very
narrow, it is easy to cause the positive and negative
speakers’ wires to contact each other, which will result in
no sound output.
How to connect the speaker wire?
Method 1: Banana plugs connection illustration
: Release the banana jacket;
: Loosen the screw;
: Insertion speaker wire and tighten the screw;
: Tighten the banana jacket;
: Insert the banana plug into the horn terminals of the
speaker and amplifier.
Note: Please make sure that the speakers’ wire are not attached
with each other, the speaker connection area is very
narrow, it is easy to cause the positive and negative
speakers’ wires to contact each other, which will result in
no sound output.
1
2
3
4
5
1
2
3
Release Jacket Loosen Screw Insertion speaker wire
tighten screw Tighten Jacket
1 2 3 4
banana plug into
the horn terminals
5

1 2 3
Bluetooth for example
Prepare: Bluetooth device (Phone for example)
Step 1: Press the Multi-function Knob to select to Bluetooth mode,
“BLU” display is flashing;
Step 2: Turn on the Bluetooth on your phone and search for:
“DA-2120B”, connect to the DA-2120B, after Bluetooth
connection, “BLU” display is no longer flashing and not
visible, “ ” will stay on.
Step 3: Open the audio application, play and enjoy!
PC-USB for example
Prepare: PC, PC-USB cable.
Step 1: Connect the PC to DA-2120B’s USB interface via the
PC-USB cable;
Step 2: Press the Multi-function Knob to select to USB mode;
Step 3: Click the sound icon in your PC’s notification area; click
the “Select playback device” option; select the playback
device - SPDIF "USB AUDIO" or “Fosi Audio DA2120B”;
Step 4: Open the audio application, play and enjoy!
Note: In USB mode, please do not insert the USB flash drive, some
USB flash drive and USB input is not compatible, resulting
in no sound output, or amplifier restart. Please unplug the
USB flash drive and try again.
Optical for example
Prepare: optical device (TV for example), optical cable.

Bluetooth for example
Prepare: Bluetooth device (Phone for example)
Step 1: Press the Multi-function Knob to select to Bluetooth mode,
“BLU” display is flashing;
Step 2: Turn on the Bluetooth on your phone and search for:
“DA-2120B”, connect to the DA-2120B, after Bluetooth
connection, “BLU” display is no longer flashing and not
visible, “ ” will stay on.
Step 3: Open the audio application, play and enjoy!
PC-USB for example
Prepare: PC, PC-USB cable.
Step 1: Connect the PC to DA-2120B’s USB interface via the
PC-USB cable;
Step 2: Press the Multi-function Knob to select to USB mode;
Step 3: Click the sound icon in your PC’s notification area; click
the “Select playback device” option; select the playback
device - SPDIF "USB AUDIO" or “Fosi Audio DA2120B”;
Step 4: Open the audio application, play and enjoy!
Note: In USB mode, please do not insert the USB flash drive, some
USB flash drive and USB input is not compatible, resulting
in no sound output, or amplifier restart. Please unplug the
USB flash drive and try again.
Optical for example
Prepare: optical device (TV for example), optical cable.

Step 1: Connect the TV to DA-2120B’s optical interface via the
optical cable;
Step 2: Press the Multi-function Knob to select to optical mode;
Step 3: Set the TV's optical output sound to RAW/PCM.
Note: Due to different TV types, some TVs default Dolby or DTS
sound output, DA-2120B does not support Dolby and DTS
sound, please select RAW/PCM sound, otherwise you will
hear a lot of noise or no sound output.
Step 4: Open the audio application, play and enjoy!
Coaxial for example
Prepare: Coaxial device (TV for example), Coaxial cable (no
include).
Step 1: Connect the TV to DA-2120B’s coaxial interface via the
coaxial cable;
Step 2: Press the Multi-function Knob to select to coaxial mode;
Step 3: Set the TV's coaxial output sound to RAW/PCM.
Note: Due to different TV types, some TVs default Dolby or DTS
sound output, DA-2120B does not support Dolby and DTS
sound, please select RAW/PCM sound, otherwise you will
hear a lot of noise or no sound output.
Step 4: Open the audio application, play and enjoy!
AUX for example
Prepare: AUX device (Fosi Audio Phono Preamp BOX X1 for
example), 3.5mm to RCA cable.
Step 1: Connect the Fosi Audio BOX X1 to DA-2120B’s AUX
interface via the 3.5mm to RCA cable;
Step 2: Press the Multi-function Knob to select to AUX mode;
Step 3: Connect the phono and turn it on, play and enjoy!
USB flash drive for example
Prepare: Max 32GB USB flash drive (audio files included: supports
MP3/WMA/APE/ FLAC/WAV audio formats)

Step 1: Insert the USB flash drive into the U-disk connector of the
DA-2120B;
Step 2: Press the Multi-function Knob to select to USB flash drive
mode;
Step 3: The device automatically plays the audio from the USB
flash drive;
Note: In the USB flash drive mode, please do not insert the USB
cable, some USB flash drive and USB input is not
compatible, resulting in no sound output, or amplifier
restart. Please unplug the USB cable and try again.
Troubleshooting/QA
1: Why do I feel that the amplifier is underpowered and
the sound is very small?
• DA-2120B amplifier has hardware volume adjustment and
software volume adjustment. Please make sure the volume of the
amplifier is adjusted to the maximum, and the volume of the
remote control is adjusted to the maximum.
2: Why do I get loud hiss noise coming from the TV via
optical input?
• Please turn off Dolby/DTS audio on your TV or TV App, DA-2120B
does not support Dolby/DTS audio input, please select RAW/PCM
sound.
3: Can the DA-2120B be powered by batteries?
• Yes, but it is not recommended. The amplifier may be damaged
when the battery power is unstable.

4: Can I use headphone with this product?
• No, the DA-2120B cannot be connected to headphones and only
supports passive speakers. when the battery power is unstable.
5: Why does the sound is cracking or make a lot of
electric noise?
• Please make sure all the cables completely pushed into the
devices, incompletely connection will cause this cracking.
• Please remove all the inputs then check whether cracking noise
disappear or not, the cracking maybe from the audio source or
input cables.
• If you are not using the original factory standard power supply,
please replace the power supply before testing. Many power
supply in the market have large interference coefficient, which
will cause a lot of current sound.
6: My Bluetooth device can’t pair with DA-2120B?
• Make sure that DA-2120B Bluetooth mode is on and “BLU”
display is flashing;
• Make sure that DA-2120B is not paired with other devices.
• Make sure that the distance between your device and DA-2120B
is not too long, put your device close to the DA-2120B to have
a try.
• Make sure there are no obstacles between your device and
DA-2120B, obstacles will affect the Bluetooth operation distance.
• Please try to change another Bluetooth audio source to test.
• Replug power supply and restart the DA-2120B and then try to
connect again, try to use another brand of mobile phone.
• Please unplug the USB flash drive, make sure no USB flash drive
plug into the amplifier.

7: No Dolby/DTS audio and I still get noise through the
USB input?
• Please switch the USB port to USB 3.0 or back USB port and try
again, as some USB ports have unstable data transmission;
• Please try again with another computer;
• Please replace the PC-USB cable and retest, contact me for
compensation if the original cable is faulty;
• Please change the power supply adaptation and retest, why?
Because of the ageing of the power supply there may be an
abnormal power supply resulting in white noise. I recommend
using the 9V-24V to power it.
8: USB Device not recognized on Windows?
• Computer sound setting: Select Start, then type device manager
in the Search box, and then select “Device Manager”.
Expand Universal Serial Bus controllers. Press and hold
(or right-click) the DA-2120B (Digital Hifi Audio) device and
select Uninstall.
Repeat for each device to uninstall.
Restart your computer.
Your USB controllers will automatically install.
• Please try another computer connection.
• Please try another USB 3.0 interface connection.
• Please try an alternative USB cable.
• Please unplug the USB flash drive, make sure no USB flash drive
plug into the amplifier.
9: Why do I get an intermittent sound?
• Please switch the USB cable to USB 3.0 port or back USB port
and try again, as some USB ports have unstable data
transmission;

• Please replace the PC-USB cable and replug power supply to
restart the amplifier, contact Fosi Audio customer support for
compensation if the original cable is faulty.
10: Can this input through USB, and output to optical with
5.1 surround?
• It cannot. The optical connection is only an input, not an output.
11: One channel does not work?
• Please make sure there is no short circuit in the speaker wire and
no short circuit in the positive and negative terminals.
• Please test whether the Bluetooth and RCA input have the same
problem first.
If the two modes have the same problem, swap the speaker
cables of the left and right channels,
If only RCA mode does not work, change the audio source,
change the RCA cable and test again, and make sure that all the
cables are completely pushed into the device.
12: Can I leave the DA-2120B power on all the time? Does
it safe?
• Sure, the DA-2120B is class D amplifier, will cost very low power
when nothing playing through it, and it's safe and you can leave it
on all the time.
13: Can I exchange the power supply come with the
amplifier and to get more power?
• The DA-2120B come with 24V 4.5A power supply, it's enough for
most bookshelf speakers, but if you want to get more power, you
can exchange the power supply, the voltage range is DC12-24V,
and you can use 24V 6A power supply or more.

13: Can I exchange the power supply come with the
amplifier and to get more power?
• Can I exchange the power supply come with the amplifier and to
get more power?
14: Can I listen to two audio inputs at the same time?
Bluetooth music and line in game audio?
• No, only one mode can be used at a time.
Any problems please leave a message to the customer
support email address: suppor[email protected].

Our website: www.fosiaudio.com
Amazon store: www.amazon.com/fosiaudio
Our Youtube channel: Fosi Audio
Our Facebook page: Fosi Audio
After-sale Service and Technical Support Email:
[e-mail]
[e-mail]
Warranty Information
• All Fosi Audio products have an 18-month limited warranty on
parts and labor from the date of purchase. Please contact us if
you have any problems.
About Fosi Audio
• Fosi Audio designs and builds innovative audio products with
all your music in mind. Great sound, simple but elegant
designs, high-quality materials, and truly useful features are
what Fosi Audio is about. We sincerely hope you get as much
enjoyment from our products as we’ve had to create them!
Fosi Audio Product’s User Manual