1 Simple Amplifier (push-pull)

This project is another simple amplifier that can be constructed with very minimal parts. This is a push pull design that when the positive signal is fed, transistors Q1 and Q3 will do the amplification process. On the other hand, Q1 and Q2 takes care the negative signals. The amplifier uses a +12V and -12V power supply and can deliver power around 2W.

amplifier schematic

Part List:
R1 - 2.7 kilo ohms 1/4W
R2 - 33 ohms 1/4W
R3 - 10 kilo ohms 1/4W
R4 - 270 ohms 1W
R5, R6 - 0.27 ohms 1/2W
D1, D2 -1N4148 or similar diode
C1 - 33uF electrolytic capacitor rated 16V
Q1 - 2N2222, 9013 or similar NPN transistor
Q2 - TIP32C or similar PNP transistor
Q3 - TIP31C or similar NPN transistor
SPK - 4 to 8 ohms speaker (2W to 4W)
DC supply - +12V and -12V dc supply

Part List Pins:

2N2222 pins

TIP32C pinout

TIP31C pinout

Other simple amps:
Simple Hearing Aid - small amp powered by 1.5V
9V amplifier -single power, minimal parts
USB amplifier - usefull for computer or laptop speakers