How to Build a Power Amplifier

By David Sandoval
Each transistor, half, the electrical signal
transistor image by Alex from Fotolia.com

Power amplifiers transform a small electrical signal into a larger electrical signal. For applications where avoiding signal distortion is important, high-fidelity amplifiers such as a Class-A amplifier may be used. For applications where the maximum amplification factor (or "signal gain") is the overriding concern, a high-efficiency amplifier such as a Class-B amplifier may be used.

Twist together the negative capacitor leads (which are marked by a "-" sign on the capacitor case). Twist together the positive lead on the first capacitor jointly with one lead from the first resistor, one lead from the second resistor, and the base lead from the NPN transistor. Solder this electrical connection.

Twist together the positive lead on the second capacitor jointly with one lead from the third resistor, one lead from the fourth resistor, and the base lead from the PNP transistor. Solder this electrical connection.

Twist together the free leads from the second and third resistors, and solder the connection.

Cut three pieces of wire, and strip 1/2 inch of insulation from the ends of each wire. Attach one end of the first wire jointly to the free lead of the first resistor and the collector lead on the NPN transistor. Solder this electrical connection.

Twist together one end of the second wire jointly with the emitter leads from both transistors. Solder this connection. Slip a ring terminal over the free end of the second wire, and solder the wire to the terminal.

Twist together the third wire jointly with the free lead on the fourth resistor and the collector lead on the PNP transistor. Slip a ring terminal over the wire twist, and solder the twist to the ring terminal.

Connect the free end of the first wire to the positive terminal on the power supply. Connect the free end of the third wire to the negative terminal on the power supply.

About the Author

David Sandoval has served as a trainer and technical writer since 2000. He has written several articles online in the fields of home improvement, finance, electronics and science. Sandoval has an Associate of Applied Science in microelectronics from Northern New Mexico College.