A little amplifier running on a 9 volt battery using the LM386. It has a switch for low (20x) and high (200x) amplification. The low is good for line signals and the high gain is good for stuff like contact mic's, coils and guitar pickups. The circuit is taken from the great book Handmade Electronic Music.

The box is made of plywood where the sides have been sanded at a 45-degree angle to create seamless joints.

veroboard design.