My Finished mini amp (new cigar box guitar build sneak peak!).
I followed the below schematic from Make's CrackerBoxAmp. It is a fairly simple amp and one can purchase everything from radio-shack. Their schematic is also similar to the circuits in the data sheet and other schematic on the internet. The only thing I changed was that I power the circuit with 12v instead of 9v. It is possible to power this circuit with a 9v battery.
I scavenged a 4" 4 ohm speaker from a surround sound speaker and the grill to protect the speaker. I made the box out of 1/4" oak.
I also used a piece of sheet metal to hold the power switch, master volume pot, 1/4" input and LED.
I also shielded the circuit board with metal tape.
Assembled box with 4" speaker.
Assembled circuit and wires.
Power input (left) and 1/8" audio jack for connecting an ipod (right).
It actually sounds pretty good!
