Simple and easy to make TDA2003 power amplifier circuit

Since the circuit uses TDA2003 integrated circuit, the circuit is simple, the passband is wide, and the sound quality is beautiful. It can be widely used in various audio and voice amplifier circuits. The
　　integrated OTL power amplifier circuit is shown in the figure below.
　　The integrated circuit (1) pin is the input terminal, and the external capacitor C2 and the external resistor R3 at the (2) pin form an AC negative feedback to improve the sound quality of the amplifier. C3 and R1 are the anti-self-excitation network, C4 is the output coupling capacitor, C6 and C7 are the power supply high and low pass filter capacitors, the power supply voltage VCC is 14.4V, the static current is 45mA, the load RL resistance is 4Ω, and the power is 6W.
　　Installation precautions (1) The order of each pin of TDA2003
　　 must be correctly judged , and welding errors are not allowed. When welding electrolytic capacitors C1, C2, C4, and C6, be sure to pay attention to the positive and negative polarity of the capacitors. 　　 (2) The voltage of the power supply VCC should not be too high or too low, and it is appropriate to be around 14.4V. 　　 (3) After soldering is completed, you can use headphones to connect to the input pin 1 in the figure with the help of the audio output jack of a radio or tape recorder. 　　 (4) A heat sink should be installed on the integrated block TDA2003 , otherwise it will be easily damaged if it works for too long.

　　Component selection: 1
　　integrated block TDA2003 , 1 resistor each of 1Ω, 2.2Ω, 39Ω, 220Ω; 1 capacitor each of 0.03μF, 0.03μF, 100μF, 470μF, 1000μF, 2 capacitors of 0.1μF; 1 speaker of 8Ω, 0.25W, 1 14.4V power supply.