What is a Pre Amp?

[bigbassdave]

Hey guys I feel like a total newb asking this but I don't know what a pre amp is. I understand the concept of hooking an external amplifier to a home theater receiver to supply extra power to the fronts or rears ect... but what is a pre amp? I was under the impression that I could hook up an external amp or two to my receiver without anything else.. Do I need a pre amp? Thanks

 

[sdy284]

"In a home audio system, the term 'preamplifier' may sometimes be used to describe equipment which merely switches between different line level sources and applies a volume control (attenuation), so that no actual amplification may be involved.

In an audio system the second amplifier is typically a power amplifier (power amp). The preamplifier provides voltage gain but no significant current. The power amp provides the high current necessary to drive loudspeakers."


taken from HERE

 

[jcPanny]

Pre/pro

To add to the above post, for HT you will need a preamp/processor or pre/pro. The processing refers to the ability to decode Dolby Digital, DTS and other formats and the DSP modes of the receiver. Modern receivers are a pre/pro and amplifier in the same box. If you want to use your receiver as a pre/pro with external amplification, you will need pre-amp output connections on the back of the receivers. Most mid-fi receivers have this feature.

 

[BMXTRIX]

Well, a little less technical...

If you know what your all-in-one receiver is. It is the thing you hook your DVD player, cable box, VCR, etc. up to. Then you connect your speakers to the speaker terminals and you have audio to your speakers.

A dedicated pre-amp is exactly like your receiver - except it does not contain ANY internal speaker level amplification. It just has low-level RCA (tyically) outputs that you jumper to an external amplifier. The external amplfiers job is strictly to amplify the low level audio coming into it, to a speaker level output.

Many people use their A/V receivers as pre-amps though. A product like the Yamaha RX-V2500 is an excellent receiver with solid controls, good switching, etc. But, some may want more power to their speakers, so they may get external amps for all, or just some, of their speakers. Then they jumper the RCA outputs from the 2500 to the amplifiers to give their system a bit more kick.

If you go to this page:
http://www.outlawaudio.com/products/index.html
You will see about halfway down the page a list of one true preamp/processor as well as two full receivers. Read the specs and you will get the idea... They are very similar, yet one includes amplification, the other does not.