This time, there is a series of audio amplifer 20W as well, but using IC TDA 2005 as a series of his base amplifier. The series of 2x20 Watt Audio Power Amplifier using TDA2005 can you see in the picture below. Technical Data: Performance of TDA2005M: (for this circuit); At 4.14 V supply voltage: 2 x 20 watts (stereo) into 4 Ohms. Distortion: Approx. 0.2% at 4 Watts into 4 ohm load. Frequency Range: Approx. 20 Hz to 22 KHz. Input Sensitivity: Approx. maximum 150 mV rms. . Power supply: + 8 to 18 volts, approx. 3.5 Amps maximum per channel. source [link]