l'm curious as to what an amp is and what it does
Toli,
In modern systems, several steps occur to get sound from your source, (TV/CD/Radio/etc), to your speakers. There can be variations in the order of some steps according to your equipment, but the steps are always there. Here they are:
1. Digital Signal Processing
Most sources today are digital... Ones and Zeros. This signal can be processed in many ways, including all the various Dolby formats, room correction stuff like Audyssey and YPAO, changing from stereo to surround, etc.
2. DAC (Digital to Analog Converter)
After all the DSP has been done, the signal needs to be converted to an analog signal because all speakers require an analog signal.
3. Amplifier (Amp)
The analog output from a DAC is at a level too low to drive speakers. (If your Receiver has "pre-outs", this is the signal present at those outputs.) Remember, most speakers do not plug into the wall for power. They get all their power from the analog signal on the speaker wires. So the signal must be amplified to carry not only the sound, but the power to drive your speakers.
All AVRs, (Audio Video Receiver), have built-in amps. So the signal present at the speaker outputs is already amplified and ready to drive a speaker. Some AVRs also have pre-outs, so you can send the signal to a separate amp if you choose. Sometimes people do this because they want more power than the AVR's built-in amps.
In the vast majority of cases, a good AVR will have enough power to drive your speakers without a separate amp.
