
The circuit diagram of a 15-watt low-distortion power amplifier using NSP5194 PNP and NSP5191 NPN transistors in the output stage, LM378 IC in the pre-amplifier, and a 13-volt power supply provides a clean, high-quality audio signal output. The circuit design relies on the complementary symmetry amplifier configuration of the PNP and NPN transistors in the output stage, as well as the use of a feedback loop for low distortion.