Fosi Audio BT10A is a Hi-Fi wireless stereo 2-channel amplifier that features 50W x 2 output, it is a mini power amp which is equipped with bass and treble control. 

Product Specifications
Product Overview & Control Functions
Package Contents​
Quick Steup
Warranty Information
About Fosi Audio

Product Specifications

Fosi Audio BT10A is a Hi-Fi wireless stereo 2-channel amplifier that features 50W 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!

Power Adapter



DC Input Range

12V - 24V


Terminating Impedance

2 Ω - 8 Ω


Max Power Output

50W x 2



≤ 0.04%





Frequency Range

20Hz - 20kHz (±1 dB)


Input Sensitivity

≤ 280mV


Input Mode

Bluetooth 5.0 and 3.5mm AUX


Output Mode

Passive Speakers


Bluetooth Transmission Distance

Up to 50ft(15m)

Product Overview & Control Functions

Package Contents​

Fosi Audio BT10A Amplifier*1 

AC Power Cord*1 

19V Power Supply*1 

Bluetooth Antenna*1 

User Manual*1

Quick Setup​


Prepare 1: BT10A, 19V power supply, passive speakers, speaker wires or banana plugs; 

Prepare 2: Connect the BT10A to the passive speakers via the speaker wire or banana plugs; 

Prepare 3: Connect the 19V power supply to the DC input; 

Prepare 4: Twist the power knob in a clockwise direction, turn on the BT10A 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

① Release the horn terminals block terminals; 

② Insert the two ends of the speaker wire into the amplifier and speaker terminal holes; 

③ 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

Method 2: Banana plugs connection illustration

① Release the banana jacket;

② Loosen the screw;

③ Insert the speaker cable and tighten the screw;

④ Tighten the banana plug;

⑤ 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.

Bluetooth for example 

Prepare your Bluetooth device (take a phone as an example) 

Step 1: Install the Bluetooth antenna to the BT10A. 

Step 2: Turn on the Bluetooth on your phone and search. “ Fosi Audio”or “Fosi Audio BT10A”, after connecting to BT10A, the indicator light shows blue light. 

Step 3: Open the audio application, play and enjoy!


3.5mm AUX for example 

Prepare: audio source (take a phone as an example), a 3.5mm AUX cable or a 3.5mm AUX to RCA cable (some devices will need). 

Step 1: Connect your phone to BT10A’s AUX interface via a 3.5mm AUX cable; 

Step 2: After connecting to BT10A, the indicator light shows red light; 

Step 3: Open the audio application, play and enjoy!


1: What type of speakers work best with BT10A Amplifier? 

• Fosi Audio Amplifiers work great with any 2-8 Ω passive speakers. But please know that the amplifier is for passive speakers, not for powered speakers and subwoofer. 


2: Can I connect a turntable to BT10A 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 BT10A. 

• As for the turntables which have a built-in preamp, the switch must be set to LINE before connecting BT10A. 


3: 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. 9-24V DC power supply are suitable.

• If you make sure the power supply is defective, please contact us for exchange. 


4: 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. 


5: Can I use headphone with this product? 

• No, the BT10A cannot be connected to headphones and only supports passive speakers. 


6: How can I switch between Bluetooth input and AUX input? 

• You can connect this amp via Bluetooth as well as wired input. But if Bluetooth connects, playback from the physical 3.5mm AUX input is interrupted. You need to turn off the Bluetooth from your device if you use AUX input when Bluetooth pairing. 

Input priority: Bluetooth input > 3.5MM AUX input. 


7: Why there is no voice from my amplifier? 

• Please check whether the cable of power supply is connected to BT10A and whether the power indicator is on.

• Make sure the BT10A's indicator light is on when the power is turned on. 

• Please check that the BT10A 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 c onnection is one of the main reasons for no sound. 

• Please make sure the Bluetooth is paired, if Bluetooth is connected, the playback of AUX input will be interrupted. If you want to connect this amplifier with a 3.5mm AUX cable, you need to interrupt the Bluetooth first. 


8: My Bluetooth device cannot pair with BT10A? 

• Make sure that BT10A is powered on. 

• Make sure that BT10A is not paired with other devices. 

• Make sure that the distance between your device and BT10A is not too long, close your device to BT10A to have a try. 

• Make sure there are no obstacles between your device and BT10A, obstacles will affect the Bluetooth operation distance. 

• Please try to change another Bluetooth audio source to test. 

• Please reconnect the power supply to the BT10A, and move the BT10A to another room to have a try. • Restart the BT10A and then try to connect again, try to use another Bluetooth device. 


9: Why Bluetooth is intermittent? 

• Please try with another Bluetooth device. 

• Make sure there is no interference from other electronic devices between the BT10A and the audio source.

• Place your device close to the BT10A. 

• Plug in the power adapter again. 


10: How to distinguish Power Switch and Volume Control? 

• Power switch means turn the power switch knob clockwise for one time to power on the BT10A. Adjusting the volume means turning the volume control knob clockwise to adjust the volume. 


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 100watts? 

• NO, this amplifier can't be bridged.


15: How can I connect BT10A to TV? 

• The 3.5mm AUX jack is the audio input. It can through 3.5mm AUX input to connect your TV. 


16: Can BT10A 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 BT10A. 

• 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 BT10A and BT20A? 

• Fosi Audio BT20A has 100 Watts*2 MAX power output, the Fosi Audio BT10A has 50 Watts*2 MAX power output. 


Any problems please leave a message to the customer support email address:

Warranty and Maintenance

• 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!


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