Many components go into crafting a home theater system. Some of these items are similarly named, and those similarities may lead to confusion regarding each item's function. For instance, an A/V receiver and amplifier are sometimes confused in the minds of consumers. However, the differences between the two are not very complicated to understand.
What an amplifier does is basically explained by its name. It amplifies sounds. An audio source, like a musical instrument or a CD player, feeds its audio signals via a cable into the amplifier, which then enhances the sound in a variety of ways and outputs it through built-in or externally connected speakers. A higher-powered amplifier, measured in watts, can produce louder sounds with more clarity. Lower-quality amps will distort the sound if it is unable to handle high volume.
A/V Receiver Basics
A/V stands for "audio and video." An A/V receiver is capable of receiving both audio and visual signals from a variety of sources, such as radios, CD players, DVD players and video game consoles. The receiver can then output these signals to a variety of displays, speakers or recording devices, like a television or CD player. An A/V receiver typically has various volume and sound controls and the ability to switch between various inputs for a single output.
An amplifier has one basic function: to amplify audio for a stronger output. An A/V receiver has some functions similar to an amplifier, namely the ability to boost the volume of an audio source and add audio effects. An A/V receiver has the added ability to take in video signals which it can then output to a video display. This is mainly used when you have numerous sources trying to feed into a single television or monitor that has insufficient input ports. This ability to handle video is the primary difference between an amplifier and an A/V receiver.