DIY Mini Guitar Amplifier: 5 Steps (with Pictures) The Case. The case is pretty simple, and can be done with plywood or any other kind of wood. I The Circuit. Since I'm using the LM386 the circuit is pretty simple, and can be found in the The Front Panel. The front panel holds the potentiometer and the P10 connector, I haven't done a Putting Everything Together. In this part all the parts will be connected, just remember to be stingy See all full list on instructables How to Build Your Own Mini Altoids Guitar Amp for About $5 Step 5: Guitar Amp. You can use this simple circuit as a portable guitar amplifier for rocking out on the street or porch. All you need to do is connect a 1/4 inch female audio jack to the audio input. Once the jack is soldered up, any standard guitar and cable can be plugged right in!