how to makeComputer Audio Booster

Here is a simple amplifier for boosting the audio level from low-power sound cards or other audio sources driving small speakers like toys or small transistor radios. The circuit will deliver about 2 watts as shown.  The parts are not critical and substitutions will usually work.  The two 2.2 ohm resistors may be replaced with one 3.9 ohm resistor in either emitter.