A tiny, cheap Amplifier where it can be incorporated almost anywhere.
Connect your MP3,iPod,Laptop,Cell Phone... and you got your self a DIY portable stereo.
It can be powered using batteries and be helpful in many cases.
It is capable to drive a small 8 Ohm speaker or even a combination of a small in diameter
say 2-3 inch woofer and a tweeter for better acoustics.
Step 1: The main ingredient
The main ingredient is the LM386N IC witch is a low voltage audio power amplifier.
Let me stay here and say that I'm not the Columbus, who discovered America!
There are plenty of information out there, just type LM386.
To begin with...