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Fosi Audio BT20A User Manual

Product Specifications
Fosi Audio BT20A is a Hi-Fi wireless stereo 2-channel
amplifier that features 100W x 2 output, and Bluetooth 5.0
streaming range up to 50ft (15m), it is a mini power amp
which is equipped with bass and treble control. Simple
compact design but practical and powerful! Home Hi-Fi
integrated amplifier designed for the customers who
pursue Hi-Fi sound!
Input Sensitivity:
THD:
SNR:
≤ 280mV
≤ 0.5%
Audio Input:
Bluetooth / RCA
≥ 98dB
Bluetooth Transmission
Distance:
Up to 50 Ft
Max Output Power: 100W + 100W
Power Supply: 24V 4.5A
DC Input Range: 12 - 24V
Frequency Range: 20Hz - 20kHz (±1 dB)
Input Mode: Bluetooth and Analog
Product Size: 130 x 100 x 35 mm
Product Weight: 700g
Terminating Impedance: 2Ω - 8Ω
Bluetooth Version: Bluetooth 5.0
Bluetooth Pair PIN Code: 0000 or 1234

Product Overview & Control
Functions
Bluetooth Antenna
RCA Input
Speakers Output
6
7
DC 24V Input
8
Bluetooth Antenna
9
Back Panel
1
2
3
Power Switch
Treble Control
Volume Control
Power Indicator Light
4
Bass Control
5
Front Panel
1
5
2
3
4
6
7
8
9
www.fosi audio.com
Fosi Audio
BT20A TPA3116 MINI POWER AMPLIFIER
On
Off

Package Contents
Fosi Audio BT20A Amplifier*1
AC Power Cord*1
24V Power Supply*1
Bluetooth Antenna*1
Instruction Manual*1
Quick Setup
Preparation
Prepare 1: BT20A, 24V power supply, passive speakers, speaker
wires or banana plugs;
Prepare 2: Connect the BT20A to the passive speakers via the
speaker wire or banana plugs;
Prepare 3: Connect the 24V power supply to the DC input;
Prepare 4: Toggle the power switch on the front panel upwards to
turn on the BT20A amplifier.
Note:
Be sure that the volume/power switch is in the OFF position
before connecting the power supply.
How to connect the speaker wire?
Method 1: 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 avoid the speaker wires being exposed and touching
the amplifier casing, as this may cause a short circuit fault.
1
2
3

24V Power Supply*1
BT20A, 24V power supply, passive speakers, speaker
Connect the 24V power supply to the DC input;
Be sure that the volume/power switch is in the OFF position
Please avoid the speaker wires being exposed and touching
Method 2: 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 take care to avoid contact between the two banana
plugs and causing a short circuit fault as some of the
banana plugs are metal cased.
1
2
3
4
5
1 2 3
Bluetooth for example
Prepare your Bluetooth device (take a phone as an example)
Step 1: Install the Bluetooth antenna to the BT20A.
Step 2: Turn on the Bluetooth on your phone and search.
“ Fosi Audio”or “Fosi Audio BT20A”, after connecting to
BT20A, the indicator light shows blue light.
Step 3: Open the audio application, play and enjoy!
Release Jacket Loosen Screw
Insertion speaker wire
tighten screw
Tighten Jacket
1 2 3 4
banana plug into
the horn terminals
5

RCA Input for example
Prepare:
audio source (take a phone as an example), a RCA cable
or a 3.5mm AUX to RCA cable (some devices will need)
Step 1: Connect your phone to BT20A via a 3.5mm to RCA cable;
Step 2: After connecting to BT20A, the indicator light shows red
light;
Step 3: Open the audio application, play and enjoy!
Note: Please keep the BT20A away from other electric device. The
BT20A can't use with a radio simultaneously.
Troubleshooting/QA
1: What type of speakers work best with BT20A Amplifier?
• Fosi Audio BT20A works great with any 2-8Ω passive speakers.
Note: please know that the BT20A amplifier is for passive
speakers, not for powered speakers and subwoofer.
2: Why Bluetooth is intermittent?
• Use another Bluetooth device to have a try.
• Ensure that there is no interference from other electronic
equipment between the BT20A and the audio source.
• Put your device close to the BT20A.
• Replug the power adapter.
3: Why does the BT20A make serious noise when used
together with a radio?
• common feature of Class D power amplifiers is that they can
cause serious noise when used with a radio, so we do not
recommend using the BT20A with a radio or too close to it.

4: Can I connect a turntable to BT20A amp, why is the
volume is extremely Low?
• As for the turntables do not have a built-in preamp, you need to
add an external phono preamp before connecting BT20A.
• As for the turntables which have a built-in preamp, you need to s
witch the preamp on before connecting BT20A.
5: Why does my power indicator not light up?
• Please check that the AC power cord is securely connected to the
power supply and to an AC power outlet.
• Please check that the AC power outlet is supplying power, make
sure the power LED on the power supply will stay on.
• Please replace another power supply and try it again.12-24V DC
power supply are suitable.
• If you make sure the power supply is defective, please contact us
for exchange.
6: 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.


7: Can I use headphone with this product?
• No, the BT20A cannot be connected to headphones and only
supports passive speakers.
8: How can I switch between Bluetooth input and RCA
input?
• You can connect this amp via Bluetooth as well as wired input.
But if Bluetooth connects, playback from the RCA input is
interrupted. You need to turn off the Bluetooth from your device if
you use RCA input when Bluetooth pairing.
Input priority: Bluetooth input > RCA input
9: Why there is no voice from my amplifier?
• Please check whether the cable of power supply is connected to
BT20A and whether the power indicator is on.
• Make sure the BT20A's indicator light is on when the power is
turned on.
• Please check that the BT20A and your source components are
turned on and not set to minimum volume, if possible replace
your source and test again.
• Check that the wire connections from the audio source to each
speaker in the amplifier are connected correctly.
• Please check that the cable is not loose, damaged. Incomplete
connection is one of the main reasons for no sound.
• Please make sure the Bluetooth is paired, if Bluetooth is
connected, the playback of RCA input will be interrupted. If you
want to connect this amplifier with a RCA cable, you need to
interrupt the Bluetooth first.
10: My Bluetooth device cannot pair with BT20A?
• Make sure that BT20A is powered on.

ou need to turn off the Bluetooth from your device if
• Make sure that BT20A is not paired with other devices.
• Make sure that the distance between your device and BT20A is
not too long, close your device to BT20A to have a try.
• Make sure there are no obstacles between your device and
BT20A, obstacles will affect the Bluetooth operation distance.
• Please try to change another Bluetooth audio source to test.
• Please reconnect the power supply to the BT20A, and move the
BT20A to another room to have a try.
• Restart the BT20A and then try to connect again, try to use
another Bluetooth device.
11: How much power does this use in standby mode? Can
this amp be left on all the time?
• This is the class D amplifier, it will cost very low power when it is
in standby mode. It can be connected all the time and it is safe
without power consumption.
12: Sound quality is not good?
• Make sure all the cables are fully connected.
• Adjust the treble and bass control of the power amplifier to
achieve the right tone.
• Please try to change the sound source and cables to test.
13: Should I unplug the power cord?
• If the item will not be used for a long time, please unplug the
power plug to prevent the item from being burnt due to lightning
strike.
14: Can I bridge channel 1 and channel 2 to get 200watts?
• NO, this amplifier can't be bridged.

15: How can I connect BT20A to TV?
• Because the BT20A has an RCA input, it can be connected to
a TV.
16: Can BT20A accept signal from a Bluetooth
microphone?
• If your Bluetooth microphone is a Bluetooth transmitter, then yes.
This amplifier is the Bluetooth receiver amplifier.
17: Why the sound cut in and cut out?
• Try to reduce the sound of the sound source.
• Try to change the audio source to test.
• Reduce the volume of the treble and bass knob on the BT20A.
• Ensure that the positive and negative poles of the speaker output
do not touch together. Some relatively large banana plugs are
easy to touch together and cause a short circuit.
18: What is the difference between BT20A and BT10A?
• Fosi Audio BT20A has 100 Watts*2 MAX power output, the
Fosi Audio BT10A has 50 Watts*2 MAX power output.
19: Can I take the BT20A to other countries?
• Yes, the wide voltage AC 110-240V for power input can be used in
any country. You only need to match the power cord adapter of
the corresponding country.
Any problems please leave a message to the customer
support email address:
suppor[email protected]

MAX Power
Output
100 wattx2 50 wattx2 50 wattx2+
100 watt
50 wattx2+
100 watt
50 wattx2
Input Bluetooth +
RCA
Bluetooth +
RCA
Bluetooth +
RCA
Bluetooth +
RCA
Output Passive
Speakers
Passive
Speakers
Passive
(Speakers+
Subwoofer
Passive
(Speakers+
Subwoofer) +
Powered
Subwoofer
Passive
Speakers+
Headphone
Power Adapter 24V/4.5A 19V/4.74A 24V/4.5A
24V/4.5A
24V/4.5A
Comparison Section
Model
Type 2.0 CH Amp 2.0 CH Amp 2.1 CH Amp 2.1 CH Amp
Picture
Bluetooth+
3.5mm AUX
2.0 CH Amp
Bluetooth
Version
Bluetooth 5.0 Bluetooth 5.0 Bluetooth 5.0 Bluetooth 5.0 Bluetooth 5.0
BT20A BT10A BT30A BT30D T20

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:
support@fosiaudio.com
fosiaudio@hotmail.com
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

