No big deal here! You can make a decent power amplifier using just three transistors. All components used here can be obtained from your electronic junk box. Also you just need a 9V transistor radio battery to power this circuit. The circuit is ideal for a pocket radio or other hand held audio equipments.
The first part of the circuit here is a preamplifier consisting of transistor Q1(2N2222). The collector of the Q3 is coupled to the base of Q2 (2N2905A),which forms a complementary symmetry pair with Q3 (2N3053). The amplified signal is available at the junction of emitter of two transistors. Checkout audio amplifier circuit too.
Circuit diagram with Parts list.
- For Q1 you can try with any general purpose NPN transistors like BC107, BC148,etc.
- For Q2 and Q3 you can try any complimentary power transistors. The result may vary slightly.No problem.
- The can be also powered from a well regulated and filtered 9V DC power supply.
- To get the power supply circuit for this amplifier.
- Checkout LA4555 Audio Amplifier here