LM386N-3 chip audio amplifier PCB. I power this with 12V DC (Add a 100µF electrolytic filter/smoothing cap across the DC power input if using a wall wart). The other values are:

R1 10 Ω ½W metal film resistor
C1 0.1 µF 50V electrolytic capacitor (or a ceramic or film cap)
C2 0.047 µF 100V box film capacitor
C3 330 µF 16V electrolytic capacitor

I have used this PCB in a couple of projects and it works well. Low noise and very compact. It operates in 20x mode (You can always bodge on a 10µF electrolytic between pins 1 and 8 if you want noisy 200x mode).