Finally all my Bluetooth Amplifier arrived. So naturally I started to tinker with them. Started with the following
“Bluetooth 4.0 Digital 2.1 Class D HIFI Power Amplifier”
- 100W subwoofer
- Left and Right channel of 50W each.
I am rummaging through my junk box trying to find a power supply that can supply recommended 24V with 5A rating. I had none, I probably had one in the garage, so I opted using my trusted modified PC power supply which can only supply up to 11V. Bluetooth module works ok, I can connect using my iPhone, but trying to connect one of the speaker using my 8 ohm speaker doesn’t produce any sound. Well I will need to figure that out later.
Over the weekend I get my speaker out, it is a Mordaunt speaker which is capable of handling up to 100W. Once I connect everything, there is no sound coming out of the speaker, only after a few seconds later the sound came out. It seems that the circuit had some sort of protection for the speaker. The sound is quite clear and crisp. I will need to make the video recording in youtube and posted later.
Second one on the list is “TDA7492P Bluetooth 4.0 Digital amplifier”
This is boasting to be capable of output 50W+50W. So I connected this to 9V battery. The Bluetooth connect seamlessly and the “Play”, “Pause”, “Next” and “Previous” button works seamlessly with Music app in iPhone and Spotify. I connect my 8 Ohm speaker to one of the output, and it produce a sound and then it stopped. I am not sure what is going on, so after looking at the speaker, one of the wire came off, so I had to solder it back, but still no luck with the speaker sound. The next test is to plug in the headphones, this works brilliantly, so I can test the “vol +” and “Vol -” button, this seems to work ok too.
When I try to connect my Mordaunt speaker to it second time around, the bluetooth light doesn’t came up any more, so I can’t connect the iPhone and play any music. It might had been damaged, so I am contacting the seller at the moment, and I will post back later with the result.
The third one in the list is “CSR8635 Dual 5W Bluetooth 4.0”
This board is small but quite powerful, it had all the bells and whistle of the second board (TDA7492P). It also have the microphone connector which the second board doesn’t have. The board have the connection for “Play”, “Next”, “Prev”, “Vol+”, “Vol-“, “Mute” buttons. Given the size you will have to connect all the buttons yourself depends on what sort of speaker you are trying to build. You don’t have to necessary connect all the buttons.
I connected one of the speaker output to my Sony surround sound speaker. I connect it to the middle speaker. The connect the power supply to +5V. The red bluetooth light light up to allow connection. Again I use the Spotify app on my iPhone, and it connect seamlessly. The sound is quite crisp and clear.