Audio amplifiers and preamplifiers are units that amplify a sound signal, which is then sent to a speaker or another amplifier

Antennas are structures or devices used to collect or radiate electromagnetic waves.

Audio amplifiers are used in circuits and systems to process audio signals

RF amplifiers are devices that accept a varying input signal and produce an output signal that varies in the same way, but with larger amplitude

Power operational amplifiers (POA) are used to increase the power of low-level signals in applications that drive low impedances or reactive loads.

Video amplifier chips are used in circuits to process video signals

Audio analyzers measure the noise and audio spectrum of output from an amplifier or a stereo