








This is a small size and cost-effective Bluetooth 4.2 Audio Receiver module with dual 5W power amplifier circuits. It supports auto-reconnect and can be powered by micro USB or 3.7V lithium battery. The module can be turned into a stereo Bluetooth speaker when connected with two speakers.

Operating Instruction
After the power is turned on, the blue indicator flashes quickly, and then the module enters Bluetooth mode; After playing the audio prompt, it goes into the pairing mode, waiting for pairing; Turn on the Bluetooth of a phone, “MH-M38”(module Bluetooth name) will be searched and displayed, click “MH-M38” to connect to the board. The connection succeeds after playing audio prompt. When the indicator is always on, you can play your music on the phone, and the indicator keeps slowly blinking when playing music.
Scenario

Note
1. Since there is no lithium battery protection circuit on the decoder board, it is recommended to use this module with a Lipo Charger board.
2. Pay attention to the electrostatic protection. Since the Bluetooth chip is very sensitive to static electricity, you must discharge the static electricity on your hand to avoid causing damage to the chip when touching it with a bare hand.
3. Bluetooth antenna signal is easy to be influenced by high-frequency or strong electromagnetic signal, so please try to keep the module away from radio transmitting devices, and this board should not be placed close to any metal objects.
The module already has dual 5W power amplifier circuits, so please do not connect the external power amplifier with this board. The negative poles of two power amplifier circuits should not be connected together, otherwise, it will destroy the power amplifier chip.
Jan 24, 2026
Nice little Bluetooth amp board for DIY audio. Audio quality is clear, pairing is fast, and the onboard amplifier has more than enough power for small speaker builds. Works well for portable speakers, bench testing, or embedded audio projects. Very straightforward and reliable.
Jan 24, 2026
Compact and convenient Bluetooth audio solution. Pairs quickly and provides clean, surprisingly loud audio for its size. The built-in 2×5 W amplifier is perfect for small speakers and DIY audio projects. Simple wiring, stable Bluetooth connection, and great value for compact wireless builds.
Jun 24, 2025
I bought another one of these of another online store and it was not as good as this one. Using the same speakers the sound is so much better. I will definitely buy another from dfrobot. Thanks