1. AV receivers
2. AV separators
3. Integrated amplifiers
4. pre-amplifiers
Hi !
I am not good at this - but I will give it a try;;
1]
AV Receiver = Audio Video Receiver
This is a 'control centre' for your surround sound - movie / game etc.
It takes a digital feed by HDMI [generally] from your Compouter / DVD / Blue Ray player & sends a HDMI - Video to your screen / projector / LCD / Plasma / LED etc.
Audio is 'processed' & sent to your front / centre / rear / sub etc. speakers.
2] AV Separates
The same as above.
However, the Processor & Amplifier are in different boxes.
The Pre Amplifier is in 1 box & the Power Amplifier is in a different box or several boxes. This will cost more & 'could' be more accurate & also more powerful.
3] Integrated Amplifiers
This is for pure 2 channel music play back.
There is no video circuit in this at all.
This is the most basic form of music play back.
Out from a 'source' [CD Player / Computer / DVD Player / Blue Ray Player etc.] is fed into an I.A. [Int Amp] & it will drive a speaker - direct.
4] Pre Amplifier
Amplification can be 'sub' divided into 2 parts.
a] Pre & b] Power
A Pre Amplifier in most cases - reduced the volume from a source.
The out from a Source [CD Player or any other - except a LP Player] is very high for a power amplifier & the pre amplifier generally does the job or spl reduction. The Voltage is reduced before it is sent to a Power Amplifier.
A Power Amplifier takes the Volts from a Pre Amplifier & increases it & also converts into current & feeds a speaker. That is why it is called an 'amplifier' it does the job of 'amplification' !!
I do hope this sheds some light & makes things clear. If you need to understand more, do feel free to pm & call me - I will try my best to make this clear to you. My knowledge too is limited, since I do not have a degree in Electronics, but I shall try....I promise !