A preamplifier is an electronic device that boosts weak audio signals before they are sent to a power amplifier. It is commonly used in audio systems, such as home theaters and musical instruments, to improve sound quality and ensure that the signal is strong enough for further processing. Preamplifiers can be found in various forms, including microphone preamps and phono preamps for turntables. They help reduce noise and distortion, allowing for clearer sound reproduction. By amplifying the signal at an early stage, preamplifiers play a crucial role in achieving high-fidelity audio performance.