An audio power amplifier is an electronic device used to amplify weak audio signals in order to drive speakers or other sound output devices to produce sound. It usually consists of two parts: a preamplifier and a power amplifier. Its working principle is to amplify the voltage of the audio signal to increase its power, thereby driving the load to produce sound. Its power adapter converts high voltage AC220V (110V) into DC voltage. Since it is used in daily life, it has high requirements for product performance and electromagnetic interference radiated to the human body. Inmark Electronics specializes in power amplifiers and audio circuits and launches triode products to meet customers' various needs.