A power amplifier takes the low-voltage signal supplied by a preamplifier, and increases it to a sufficient level to drive speakers. Receivers contain both preamplfier and power amplifier sections, eliminating the need for a separate amp and preamp.
Takes the low powered output from a Pre Amplifier (see below) and drives the speakers. By separating the Pre amplifier stage from the Power amplifier stage, normally contained within the same box in a stereo integrated amplifier, the internal interference is reduced giving a stronger, higher quality sound. The Power amp takes the variable signal and amplifies it by a fixed amount - the volume is controlled by the Pre amplifier.
The main component of any amplifier, it is the part inside the amp where the recorded sound is reproduced to be as loud as the amplifier can make it, the more energy the amp can handle the louder the power amp will make the sound.
An amplifier intended to increase the power of a signal enough to drive a load such as an antenna. Typically, power amplifiers also have large values for P1dB, indicating low distortion at high output power.
An electronic device that increases the volume of a signal. A basic unit of all sound systems. Power amps are typically connected to a preamp which provides controls for individual functions: level, tone, etc.
Power Amplifiers are very simple devices in concept. They take a small signal and increase its power so that a loudspeaker may be connected to its output terminals. Home theater power amplifiers come in many configurations and power ranges. In any system one amplifier "channel" is needed for each speaker in your home theater system. (Note: Some sub-woofers include their own internal power amplifier so you might only require five channels of amplification). Some power amplifiers combine all five or six amplifiers in a single chassis, others, which are sometimes called "mono blocks," will only power a single loudspeaker. How much power do I need? The answer to that question is not simple. It is a complex relationship between the size of your room, the efficiency of your speakers, and ultimately your individual requirements for volume or sound pressure level (SPL). Generally amplifier power outputs of less than 50 watts per channel are considered "low," 50 to 100 watts "medium," and over 100 watts "high."