Category: Amplifiers

I recently bought this board for a personal project for my house. I thought it will be helpful for some folks out there that are planning to buy one. The board specs are impressive but you’ll be disappointed when you learn the actual figures. It turns out, those specs are just for marketing reasons.

The BAD things about this module

Wrong Output Power Claims

It claims 120W x 2 output power but in reality it only can handle 50W x 2 output max. Why? It only have 1 TPA3116 Amplifier chip on board which is only capable of delivering 50Wx2 power output. The large heatsink made me think that it have 2 TPA3116 chip but I was wrong. Looking at the bottom it will become obvious that it is only using 1 IC.

Aux input not Working

The aux input circuit is wrong. It is connected to the output of the op-amp which is a bad idea. Although this connector is not labelled “input”. But I know most of us will assume this is an Aux input as most bluetooth amplifier have. Based on the schematic, it will work as an Aux output rather than input.

Muting the Main Amplifier when no music is Playing

The bluetooth module is programmed to automatically mute the TPA3116 amplifier chip when nothing is playing on the bluetooth receiver or it is not paired. This is the reason why there is no audible hum even if I am touching the amplifier inputs.

Annoying Power on sound

It is not an issue if you are only using it with small speaker but it is very annoying for a 100W speaker. Or maybe its just me. The power on sound is a 3 note melody if I remember it right.

LM1875 is an old yet reliable Audio amplifier IC. It is very common and you can get it for very cheap price. With this IC you can get up to 30W power output with 33V supply using 8 ohms speaker.

It has very simple circuit and very easy to build because it requires few components. This design is for single supply application. You can find more information about this IC on its Datasheet on this link.

PCB Design

This time around I am playing with Kicad. It’s is very different from what I used to but it has more feature and best of all its free! The layout is not yet optimized(i.e. size of the trace) because i am still learning. But you can download the project file so you can edit it for your own project. The size of the capacitors are just assumed.

3D render

The best about Kicad is that it has built-in 3D rendering feature for your board at no cost. This is a very useful tool for visualizing your project.

Downloads

You can download the Kicad project here:

Download page

 

This is a very simple amplifier that can be used for your room sound system, kitchen or even for home theaters satellite speaker. It only requires few components at a very small board. It can operate at 12V supply. It can be able to deliver up to 12W at 4 ohms and 22V supply.

Continue reading “12W amplifier with TDA2008 IC”

I have been wanting to build an amplifier like this but I have no time to build it so I thought I can just share this design and let you readers build it. The design is pretty much similar to Elliott’s Amplifier design with very minor tweaks. As usual I always simulate my design with simetrix to validate that my circuit is working correctly.

Continue reading “60-100W amplifier project”

This circuit can actually deliver up to 70W at 4 ohms at 10% THD at 14.4V power supply which is very suitable for car audio applications. Make 4 of this amplifier and you will have a powerful 280W audio system for your car which will be very loud. Continue reading “70W Car Amplifier Project”

Many years ago, it is not easy to build a powerful audio amplifier. You will need big power transistors with massive heavy heatsinks plus a heavy transformer too. It will also require a lot of efforts to build it, from drilling the heatsinks and connecting those wires. It is a very tiring task. Today a 200W amplifier can be as small as your mobile phone. Thanks to the evolution of Class D audio amplifiers. Smaller and more efficient amplifiers are now possible.

Continue reading “TDA7498 – 200W class D audio amplifier”

In case you wan to build an small amplifier for your small speaker, here’s a 3W per channel amplifier for you. Take note that this can only operate up to 5.5V. You can’t use USB to power this circuit as USB can only provide up to 2.5W power. If you will use 8 ohms speaker, it can only provide up to 1.4W of power.

Minimum value of Ri is 18k. Minimum speaker impedance is 4 ohms.

Here’s a simple amplifier that I used for my speaker project. The IC operates at 5V. Note that although it runs on 5V, it can’t be powered via USB because USB can only deliver 2.5W. Ri minimum value is 18k which will give you 24dB voltage gain. The voltage gain is computed by equation : 20 log(2*(142k/Ri))