Hi,
I am new to this Forum.
I want to know the Difference between the following.
Amplifier / AV Receiver / Pre Amplifier.
What are the practical applications of each?
When is an Amplifier used over an AV Receiver and so on..
I think I have answered this before but here goes:
A stereo (2 channel) integrated amplifier consists of the following integrated into one box
1. A pre-amplifier (mild boost to input signal, volume control, allows switching between multiple audio analog inputs - analog output from CD player or Blu ray player, media player, radio, tape player, vinyl turntable, etc.)
2. A power amplifier (amplifies the mildly boosted signal from the pre-amp and boosts it to enough voltage that can drive speakers)
A stereo receiver is a stereo integrated amplifier with an AM/FM radio built-in. Modern units will also support digital or internet radio, and streaming sources like Spotify, Pandora, etc. In addition, the digital models also have a built-in DAC or Digital to Analog Converter. This converts the digital input (digital audio stored in bits and bytes) to analog audio waveform that actually drives the speaker (and that the preamp and poweramp actually amplifies). You will hear terms like Burr Brown (a DAC chip), 24/192 or DSD (high resolution digital audio formats that are higher than CD - which is 16/44.1), etc.
An AV or audio-video receiver is similar to a stereo receiver, except it supports more than 2 channels. Typically 5.1 (5 amplified audio channels and 1 subwoofer unamplified channel - because most subwoofers have a built-in amplifier). But it can also be 7.1 or 9.1 or Dolby Atmos (supports a grid like array of speakers - from what little I know). Since multi-channel audio is difficult to setup correctly in most rooms, most units also come with some form of "room correction" or "eq" or equalization. Think of graphic equalizers of the past, except these are more sophisticated, and fully automated. You hook up a small mic and move it around in the room, and it adjusts the sound from various channels so the music and effects sounds good in all parts of the room. Common room correction technology is "Audussey", ARC, Dirac etc.
This is the audio part of the AV receiver. The video part of the audio receiver consists of an HDMI switcher (allows you to switch between multiple HDMI sources - TV, xbox, media player, blu ray player, etc). Many AV receivers or AVRs also contain a video engine that enhances or sometimes upscales low resolution or low quality input video signals to make it better. Most TVs also do this nowadays, by the way.
The trade-off usually is - the more the component integration, the less the quality of individual components. And the more individual components you buy to "assemble" your system, the better quality you get, and the better control you get in terms of how your system sounds. Plus, upgrades of individual components down the line are significantly cheaper, and individual component failures are less expensive to rectify as well. Downside is more wiring is required and more space is required. And often, the final price is significantly higher (although intelligent purchases can keep it down). But the sound quality difference is often quite dramatically better.
An entry level 5 channel or 2 channel power amp for example will beat the pants off the power amp section of even most mid-range AVRs. Most AVRs play the "features game" because frankly put, people buy devices based on features, not based on actual build quality or even actual audio/video quality. Still, features are sexy and convenient too.
