Introduction: LM380 Bluetooth Stereo Amplifier System

About: An electronics hobbyist

Always thought of a good stereo distortion free speaker system with bluetooth capability right??? I hope many guys have tried the LM386 with a lot of capacitors and still it produces noise after a certain limit.

Here I will introduce with you with this LM380. This is slightly costly than the LM380 but its capabilities exceed it's cost.Only one filtering cap is needed at the output side.It is a mono Amplifier IC. So two of them together can act as a stereo amplifier. operating voltage is 10-22V. Power output of each side is 2.5W(some losses are there still though). Here I also have added a Bluetooth capability so that you can use it as a bluetooth speaker as well.

So let's start.....

Step 1: Parts Needed

Things required-

1. 2 LM380 with heatsinks

2. some connecting wires(if using breadboard)

3. breadboard

4. 2 470uF capacitor

5. 2 10K potentiometer

6 12V power supply

7 2 speakers

8 Bluetooth MP3 player module

9 3.5mm socket

Step 2: Circuit on Breadboard

Follow the circuit as given in the picture and build it on breadboard.

Inserting two of LM380s would look more or the less like as on the picture

Step 3: Inserting the 3.5mm Socket and Output Speakers

Now as the building the circuit is over, it's time to install the 3.5mm socket as input and speaker output .

This socket usually have 3 pins. One is the common ground. Other two are the left and right channels for the audio input. Those two channels are also depicted in the schematic.So insert the common to the ground and the other two as in figure.

Now you can attach speaker wires directly or you can use RCA connectors as I used.Since I have 2 creative speakers with RCA connector . Speakers have one common ground and the other as the audio out. So insert ground to ground and the other to the audio out.Same goes for RCA socket(2 pins).

Step 4: Adding Bluetooth Functionality

Now it's time for Bluetooth!!!

get yourself one Bluetooth MP3 receiver from any online site. It's cheap.The picture of it is given. It simply requires 5V input and can be connected by phone. The output of this module is connected to the input of the LM380s via the 3.5mm jack given with the kit. So it means you can now pair with your phone and can play any song.

power on your 12V power supply.

Now build a 5V power supply .Check out my link for it

So now Power up the BT MP3. It might need a pass of 1234 or 0000 or as per instructions of the kit for pairing it with your phone.

After pairing, Play a song now and test it everything is clear or not. If not check all connections again

Step 5: Soldering

So after test is complete solder all the components on a piece of perfboard.It will take a maximum of 1hour.It will then result in more clear sound. Also attach the 5V supply. Add 2 heatsink to the can also remove the Bluetooth if you want to use a computer or home theater speaker. You can make a wooden chassis and place all components and your Amplifier System is Complete, congrats!!!