Simple 2.5 Watt AF Amplifier using AN7523

This audio frequency amplifier circuit is built around the AN7523 integrated circuit, which functions as the core active amplifying element designed to boost weak audio input signals to a level capable of driving a loudspeaker. Power is supplied by a 9V battery, which provides the necessary DC voltage rail to energize the internal transistor stages of the AN7523 IC. Input audio signals are coupled into the circuit via capacitors such as C2 and C4, which block DC voltage components while allowing AC audio signals to pass through. The resistor network consisting of R1 (47K), R2 (33K), and the 10K preset potentiometer (VR1) acts as a voltage divider and biasing configuration, allowing the user to adjust the input signal level or volume going into the amplifier stage. Electrolytic capacitors like C1 (470µF/25V) and C3 (10µF/25V) serve vital filtering and decoupling roles, stabilizing the power supply rails by shunting high-frequency noise to ground and providing charge storage to support sudden bass transients demanded by the 8Ω/3W speaker. The amplified output signal is then delivered directly to the speaker through the 2-pin socket and connector wires, converting the electrical audio waveforms back into audible sound waves. The entire circuit is assembled on a custom PCB using an 18-pin IC socket to safely mount the AN7523 without exposing it to excessive soldering heat.