If you want to build a simple Bluetooth based amplifier board, Audio B plus Bluetooth audio receiver can be a good choice for your project. This is a Bluetooth 4.0 stereo receiver board. It is based on CSR8635.
We have used 2x10 2mm space male breakout pins. You can integrate it to your project easily.
Single-ended signal output with Audio amplifier
Single-ended signal output with headphone/small speakers
Differential signal output
How to use:
Quick press S2 to switch to go the previous song, long press to reduce the volume.
Quick press S3 to switch to the next song, long press to increase the volume.
Press S1 to play or pause.
If there is an audio output, MUTE pin will be high level, otherwise, will be low level.