The basic composition of power amplifier and its role
A power amplifier usually consists of three parts: a preamplifier, a driver amplifier, and a final stage power amplifier.
1. The preamplifier plays a matching role, and its input impedance is high (not less than 10kΩ). Most of the previous signals can be absorbed, and the output impedance is low (below tens of Ω), and most of the signal can be transmitted. At the same time, it is itself a current amplifier that converts the input voltage signal into a current signal and gives appropriate amplification.
2. The driver amplifier acts as a bridge. It further amplifies the current signal sent by the preamplifier and amplifies it into a medium power signal to drive the final stage power amplifier to work normally. If there is no driver amplifier, the final stage power amplifier cannot deliver a high-powered sound signal.
3. The final stage power amplifier plays a key role. It will drive the current signal from the amplifier to form a high-power signal, which will drive the speaker to sound. Its technical specifications determine the technical specifications of the entire power amplifier.