Troubleshooting/QA​ Troubleshooting/QA​ 1: 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-2120C does not support Dolby/DTS audio input.

2: Why am I not getting enough power from DA-2120C to compare to a 50W x2 amplifier?

• For low power, please long-press remote: "DISPLAY" to boost gain to +6dB.

3: Can this product be used at 220 volts?

• Yes, the power supply can work at any AC 110V-240V.

4: Does the DA-2120C support Bluetooth 5.0 & aptX?

• The DA-2120C supports Bluetooth 5.0 and backwards compatibility with 4.2, 4.0, etc. Also, the DA-2120C supports Bluetooth aptX.

5: Why can't I use aptX to connect to the DA-2120C?

• The DA2120C supports aptX but still requires a Bluetooth device e.g. mobile phone) that also supports aptX to work. Please check that your Bluetooth device has aptX enabled or seek support from your Bluetooth device's customer service for further assistance.

6: Can I use headphone with this product?

• No, the DA-2120C cannot be connected to headphones and only supports passive speakers or active subwoofer output.

7: 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.

8: My Bluetooth device can’t pair with DA2120C?

• Make sure that DA2120C Bluetooth mode is on and “BT” display is flashing; “BT” display is always on to indicate that it is connected.
• Make sure that DA2120C is not paired with other devices.
• Make sure that the distance between your device and DA2120C is not too long, close your device to DA2120C to have a try.
• Make sure there are no obstacles between your device and DA2120C, obstacles will affect the Bluetooth operation distance.
• Please try to change another Bluetooth audio source to test.
• Replug power supply and restart the DA2120C and then try to connect again, try to use another brand of mobile phone.

9: 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-32V power supply to test it.

10: 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-2120C (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.

11: 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.

12: 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.

13: Why is the actual power sometimes very powerful, but sometimes the actual power per channel seems to be less than 120W?

• The product factory again and again after rigorous testing, under normal circumstances the rated power is completely up to 120Wx2, but the actual use of the product power size and the type of speakers also have a relationship.

14: One channel does not work?

• 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, or change another speakers, and then test whether this channel still does not work;
• If only RCA or Bluetooth 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.

15: DA2120C supports subwoofer, is it possible to connect the subwoofer directly?

• The sub output can be connected to active/powered subwoofer or to subwoofer amplifier then to passive subwoofer.

16: Can I leave the DA-2120C power on all the time? Does it safe?

• Sure, the DA-2120C 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.

17: Can I exchange the power supply come with the amplifier and to get more power?

• The DA-2120C come with 32V 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 DC12-36V, you can use 36V 8A, or 36V 10A power supply or more.

Any problems please leave a message to the customer support email address: support@fosiaudio.com.