Introduction: Super Simple AN6884 Vumeter!

Picture of Super Simple AN6884 Vumeter!

Hello everybody! Today I'm going to show you how to make this little super simple 5-led vumeter!

I'm sure you won't have any problem because all the materials needed are very common and the circuit is super simple!

Also I have to give the credits to NikoTec - Nicolás J. Pérez - Murphy, Santa Fe, Argentina, the author who wrote this website:

I'm just showing that I made it and I don't want to violate any law. If anybody has a problem with this instructable just say it.

Let's start!

Step 1: Step 1: Materials Needed:

We will only need a few and very common materials to build up our vumeter.

The materials are the following:

1 - 100 ohm resistor.

1- 10K resistor.

1- 10K potentiometer.

1- 2.2uf capacitor 16V (or more).

1- 10uf capacitor 16V (or more).

5- LEDs (For this I've used 3 green ones and 2 red ones). You can choose between 5 or 3 mm.

1- Integrated circuit AN6884

- Some wire

- PCB ( you can use a perfboard or you can etch one by yourself, we are going to do this)

I'm sure you have these in your material box or you can buy them in your local store so I'm not going to write the pages where you can find them. Anyway, if you feel you need it, just say it in the comments and I will be very happy to search the parts for you!

Apart from that we will need a drill and bits and a soldering iron

Step 2: Step 2: Making the Printed Circuit

Picture of Step 2: Making the Printed Circuit

We are going to make our own board so we will need to transfer the circuit and to etch it.

I have used the toner transfer method. First, I printed the circuit with a LASER printer in a thermal paper. After cleaning the board with alcohol, I've ironed the circuit and after that, I peeled off the paper very carefully. I've etched the board with hydrogen peroxide and hydrochloric acid. To remove the ink I've used alcohol and a steel wool. And that's it, now we have the board.

Step 3: Step 3: Drilling the Holes.

Picture of Step 3: Drilling the Holes.

Once we have the board we need to drill the holes. So grab your drill and bits and start making holes! This is where we are going to place the components.

Step 4: Step 4: Component Placing and Soldering.

Picture of Step 4: Component Placing and Soldering.

Now we are ready to place the components and to solder them. Just follow the image (it is very clear where everything goes). I've decided to solder the tracks because it looks cooler. There are two sockets that I decided not to use because I soldered the cables directly to the board. We have two wires for the audio input and two more for the power input. The power is 12 volts dc.

Step 5: Step 5: Connecting the Wires.

We are almost done! The last thing we have to do is to apply power and then plug the audio cables in the exit of your music player. If everything was done well, you have your own mini vumeter!!!

Step 6: Step 6: Testing.

Once we have everything connected, we are going to test our vumeter. Make sure to connect the positive lead in the respective positive speaker terminal and the same with the negative. Then, just apply power (It says 12V but it can work with less) and watch the leds dance with the music. You can use the potentiometer to calibrate the leds.

I hope you found this instructable easy to follow and I hope you have fun with your new vumeter. If you have any question just ask and I will do my best to answer you!


tttapa (author)2016-03-17

Nice project!
One trick however, is to add a diode in series on your input. Otherwise the AC audio will constantly charge and discharge the capacitor, resulting in dim, flickering LEDs. If the amplitude of your audio level is too low, you could add some input stage (a small 1-transistor class A preamp or maybe even an opamp) or try to bias the diode using two resistors, since diodes have a forward voltage drop (ranging from 0.4 to 0.7V, depending on the type). This can be quite a significant loss in amplitude when using a small audio signal.

Alexisgm97 (author)tttapa2016-03-18

Thank you very much!!!

I appreciate your great feedback and your improvements. It is true that the leds do flicker a little but the aim of the project was to keep it simple, I mean, to use just a few parts and to make the whole Instructable simple. Anyway you seem an expert of this!!

Could you draw an schematic or specify the parts for me? I don't really know much about diodes and preamps but I would really like to start!