Introduction: Build a Simple Speaker System With LEGO!

About: Tanmay Bhonsale a.k.a enceladus2000

Hello everyone! In this Instructable, I will show you how I made a speaker with some circuitry and a case made with LEGO! I got the idea while searching for a case for the speaker. I had an old LEGO house set. Lego is easy to use and is literally child's play. So why not make the speaker's case with it?

I have shown how I made my case in this Instructable, But you can modify and customize it any way you want. All circuitry is simple and on a small breadboard, so newbies in electronics are welcome to go ahead and make it!

Note: The above video is a demonstration of the amplifier circuit on the breadboard. It's just to show you that it actually works and give you an idea of the sound quality...

Step 1: About the Speaker...

The audio amplifier circuit is based on the LM386 IC. Of course, it isn't the best amplifier around, but it works well enough for someone new to audio. The amp sports a gain of up-to 200 and power output up-to 580mW .

Cross over distortion is slight, at <2%, however overall sound quality is quiet good. There isn't much distortion at high volumes too. My speaker is powered by a heavy-duty 9v battery, but it is recommended you use a power supply.

Step 2: Materials Required...


LM386 Audio IC

0.1 uF capacitors

220uF capacitor

100uF capacitors

10ohm resistor

Jumper wire


0.5 - 1W 8ohm Speaker

1-10K Potentiometer


Lego blocks

9v Battery OR 1A 10v Power Supply

AUX cable

Step 3: Building the LEGO Case

Collect your LEGO pieces, and start building! Keep in mind the size of the speaker, breadboard and battery; they must fit in later! See the pics for how I built the case...

Step 4: The Circuit...

Start by putting the LM386 in the breadboard, then follow the pictures; jumpers first, capacitors and resistors later. Speaker, potentiometer and AUX cable will be put in a later step...

Step 5: Preparing the AUX Cable and Speaker...

Solder some jumper wires to each of the contacts on the AUX cable, as shown in pictures. Also solder some wires to the speaker's terminals. Then you can proceed to the next step...

Step 6: Putting the Circuit Together...

Connect both the left and right channels to the amplifier's input. See the above picture for the AUX cable's pinout. 'GND' is connected to ground. One terminal of the speaker is connected to ground and the other to the -ve terminal of the 220uF capacitor. After testing, you can secure the speaker and cable's connections with tape.

Step 7: Putting the LEGO and Circuit Together...

Follow the pictures for this. Make a "hole" in the LEGO for the potentiometer and AUX cable. Place the speaker and add extra LEGO blocks for holding it in place and to make the full case look good.

Step 8: Plug in Your Phone and Enjoy!

Well, just plug your phone in, and play your favourite tunes loud!

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