Product Specifications

Fosi Audio BT30D PRO is a HiFi Bluetooth 5.0 power amplifier that features SUB volume / Frequency control, Bass / Treble control. Support Bluetooth or RCA input, suitable for most passive speakers, passive/ powered subwoofer. Adopt TPA3255 high-performance chips to output 680W stably, low distortion to show ultra-high-definition sound quality. The perfect solution to meet all your audio needs! Let’s join the audiophile’ s music journey with Fosi Audio BT30D PRO!

Audio Input:Bluetooth / RCA
Output Interfaces:3.5MM full-range output, Speaker’s / Subwoofer output
Output:Passive Speakers / Subwoofer +Active Speakers / Subwoofer
Power Amplifier Chip:TPA3255
DC Input Range:DC 12-36V
THD:≤ 0.04%
SNR:≥ 108dB
Frequency Range:20Hz – 20kHz (±1dB)
Input Sensitivity:700mV
Terminating Impedance:2-8Ω
MAX Power Output:165W(@ 4Ω) x 2+350W(@ 2Ω)
Bluetooth Transmission Distance:Up to 50 Ft (Without obstacle)

Product Overview


Package Contents

Fosi Audio BT30D PRO ×1

Bluetooth Antenna ×1

User Manual ×1

Power Adapter ×1

Quick Setup

How to Use?

Step 1:

① Connect the power adapter to the socket and the BT30D PRO. Please make sure the green LED light on the power adapter stays on.

② Connect the active (powered) speakers to the BT30D PRO.

③ Connect passive speakers to the BT30D PRO using banana plugs or bare wire. Then turn on the power switch.

Step 2:

① RCA line input: Use an RCA cable to connect the BT30D PRO and your device. The input mode indicator light will turn red after a successful connection.

② Bluetooth input: Turn on the Bluetooth on your device, then select “Fosi Audio BT30D PRO” for pairing, the input mode indicator light will turn blue after a successful connection. Once Bluetooth is connected, the RCA input will be interrupted. If you want to use the RCA input again, just disconnect the Bluetooth.

Step 3:

① Adjust the volume control, SUB volume/ Frequency control, Bass / Treble control, then enjoy it!

Note: Make sure that all the cables are completely pushed into the device.


1. Get noise when playing music?

  • Try to use other Bluetooth devices. Weak or unstable Blue- tooth signal will cause this problem, try to close your device to the BT30D PRO.
  • Try another RCA cable and make sure the audio cable is connected correctly.
  • Please unplug the RCA cable from the amplifier, and then turn it on to have a try.
  • Please change the audio cable and audio source to have a try.
  • Did you set the “treble” volume to the top? Please volume down the “Treble” volume.
  • The gain of BT30D PRO is larger than other model, you can volume down the “Treble” sound. Some speakers are very sensitive so that the white noise will be obvious, it’s normal that BT30D PRO has some noise when you turn up the “Treble” volume.
  • Make sure that all the cables are completely pushed into the device, incompletely connection will cause this issue.
  • Please keep this device away from other electronic devices.

2. All cables are connected, but there is no audio output?

  • Please check the indicator light on the front panel of the amplifier and the power supply are on.
  • If the indicator light is on, please check if the volume knob is at the minimum state, if it is, please turn up the volume.
  • Make sure that BT30D PRO is in the play mode you want.

Note: Bluetooth input mode (the input mode indicator light will turn blue). RCA input mode (the input mode indicator light will turn red). Once Bluetooth is connected, the RCA input will be interrupted.

  • Please check if the audio source is paused.
  • Please try to change the sound source, cables and speakers /subwoofer.
  • Restart the BT30D PRO and your device, then try to connect again.

Note: Make sure that all the cables are completely pushed into the device.

3. My Bluetooth device can’t pair with BT30D PRO?

  • Make sure that BT30D PRO is on and the LED light on the power adapter is green.
  • Make sure that BT30D PRO is not paired with other devices.
  • Make sure that the distance between your device and BT30D PRO is not too long, close your device to BT30D PRO to have a try.
  • Make sure there are no obstacles between your device and BT30D PRO, obstacles will affect the Bluetooth operation distance.
  • Please try to change another Bluetooth audio source to test.
  • Please replug the power supply, move the amplifier to anoth- er room and test it again.
  • Restart the BT30D PRO and then try to connect again, try to use another brand of mobile phone.

4. 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 speaker, 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.

5. Can I connect a turntable to it?

  • If your turntable has a built-in phono preamp, you can directly connect the BT30D PRO to your turntable with RCA cable.
  • If your turntable does not have a built-in phono preamp, you need to add a phono preamp to the turntable and BT30D PRO, similar to our BOX X2.

6. Can’t power on? 

  • Make sure that the LED light on the power adapter is on.
  • If it does not light up: unplug the power adapter from the BT30D PRO, plug the power adapter directly into the AC power source, and see if the LED will light up. If it still does not light up, it may be a problem with the power adapter. Please contact us to replace the power adapter.
  • Is there any other DC12-36V power adapter at home? You can use the camera or router’s power adapter to connect to the BT30D PRO, test to see if the BT30D PRO can be turned on.

7. 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.

8. Does the BT30D PRO support Bluetooth aptX and Low Latency?

  • No. BT30D PRO does not support Dolby, aptX, aptX HD and aptX Low Latency.

9. Can this amp be left on all the time?

  • It can be connected all the time and it is safe without power consumption.

10. 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.

11. Do I have to connect all the outputs of BT30D PRO? Can I only connect one speak- er? Or just use it as a subwoofer preamp?

  • Yes, you can do it. You don’t need to connect all the outputs.

12. Can the BT30D PRO be used as a 2.0 channel power amplifier? Can it be used without connecting the subwoofer?

  • Yes

13. What does the SUB freq knob do? Does it only adjust the frequency output by the passive subwoofer?

  • SUB freq is to adjust the output frequency of passive subwoofer, the adjustment range is 0-300Hz.

14. Is the Bass adjustment effective for the passive subwoofer of the BT30D PRO?

  • Yes, it works.

15. Why Bluetooth is intermitent?

  • Try to change a Bluetooth device.
  • Ensure that there is no interference from other electronic equipment between the BT30D PRO and the audio source.
  • Put the sound source close to the BT30D PRO.
  • Replug the power adapter.

16. What speakers are suitable for the BT30D PRO?

  • BT30D PRO is suitable for most home audio-visual systems, it can drive 20-200 watts, 2-8 ohms speakers.

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 bass amplifier.
  • 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. Can I take the BT30D PRO to other countries?

  • Yes, the wide voltage AC 110v-240V for power input can be used in any country. You only need to match the power cord adapter of the corresponding country.

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!

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