2 Watt Stereo Audio Amplifier Circuit based IC KA2209 a circuit designed for the purposes of such a small audio amplifier. For example a mini tape, smartphones, mp3 players and others that require audio gain not too high.
This circuit is very simple and can work well if using batteries. KA2209 IC which inside there are already two amplifiers so that a stereo amplifier can be made easily enough using one only IC.
IC KA2209 has 8 pins. Because of their small size, these ICs are widely used in portable audio amplifier like a Walkman. Voltage required for this amplifier is 1.5V to 9VDC.
If the IC KA2209 difficult to get in your place, it can be replaced with type TDA2822 IC, which IC that has characteristics similar to the KA2209.
Keep in mind this stereo audio amplifier circuit is suitable for battery operation. If using a power supply, many complained about the hum of the power supply. If you are planning to build this amplifier with an power supply, please use a power supply that is already well-regulated.
2 Watt Stereo Audio Amplifier Circuit based IC KA2209 parts list:
R1, R2 : 10K brown black orange
R3, R4 : 4R7 yellow violet gold
C1 : 10uF mini
C4, C5 : 100uF/25V electrolytic capacitor
C2, C3 : 470uF/16V electrolytic capacitor
C6, C7 : 100nF box capacitor
8 pin IC socket