AV receiver
[1] A "receiver" in its most basic form is an amplifier, typically at least a two-channel stereo model, that has a built-in radio tuner.
Over time, features were integrated that would otherwise require separate pieces of equipment, such as preamplifiers, equalizers, and multiple power amplifiers.
Video switching was added to simplify changing from one device to another, though this role diminished once TVs began supporting multiples of the same type of input connector.
The fundamental purpose is to take the low-level audio signal of a turntable, CD player, radio tuner, or other device and boost it to a level that can drive speakers.
Because of these factors, it is not easy to compare the perceived loudness of amplifiers solely from their specified power in watts.
[6] The first common soundtrack format was Dolby Pro Logic, a surround sound processing technology.
Dolby Digital ready receivers included inputs and amplifiers for the additional channels.
A somewhat less common surround sound decoder called DTS is standard on current AV receivers.
With the introduction of high definition players (e.g. Blu-ray Disc and HD DVD), yet more decoders have been added to some receivers.
Most receivers offer specialized digital signal processors (DSP) made for handling various presets and audio effects.
Some may offer simple equalizers and balance adjustments to complex DSP audio field simulations such as "Hall", "Arena", "Opera", etc.
that simulate or attempt to replicate the reverb as if the audio were being played in the places through use of surround sound and echo effects.
Standard connectors include: Analog audio connections usually use RCA plugs in stereo pairs.
Analog audio connections using XLR (Balanced) connectors are uncommon, and are usually found on more expensive receivers.
In the last years, since vinyl players are gaining popularity, there are some manufacturers of A/V receivers which are offering a phono input on some models.
This feature is mainly offered to allow people owning a turntable to connect it and listen to their vinyl collection.
HDMI has become the de facto standard for passing video and audio on AV receivers.
AV receivers though primarily used for amplification may or may not have an inbuilt AM/FM radio tuner among other features such as LAN connectivity for various Internet applications and some with multi-room audio solutions.
Some models have Internet radio and PC streaming access capabilities with an Ethernet port.
