General Purpose LM386 Power Amplifier

Here is another general purpose LM386 power amplifier circuit that works quite well. Over the years I have built many of these and found that there are some layouts that work better than others. If you look at the internal schematic of this IC, you will see that the transistor count is quite small, and consequently this type of amplifier works well when there is a well established audio signal.

As you can see, the input design of this IC is almost like an operational amplifier, and in this particular circuit implementation the inverting input is connected to ground, and we use the non inverting input on pin 3. As you can see, there are not very many intermediate stages for signal amplification; hence the audio signal has to be strong to begin with.

Board Layout

Component List