A great 40 W audio mono amplifier built with TDA 2030, BD 712 and BD 711. The output power is 22W on 8 ohm speaker and 40W on 4 ohm. Distorsions are 0.012% at 1khz/8 ohm/11W and 0.032% at 1khz/4 ohm/20W. The IC1 supply curent variates accordingly to the audio input signal so there will be a similar variation on R6, R7, R8 and R9. As long the current is arround 1A, the voltage on the resistors is insufficient to open T1 and T2. This mean that output power smaller than 2W on 4 ohm will be outputed by TDA2030. This is a great audio power amplifier as I know because I’ve build one.
The voltage power supply is between 12V and 40V.
TDA2030 40W amplifier circuit diagram
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