pre amp, amp theory

[icarus]

I use an amp, pre amp set up, but to be honest i don't know the science behind them. so if someone could explain this to me it would much appreciated.

[icarus]

I understand the basics principles like the amplifier converts the low voltage, low current signal into a higher current signal suitable for driving speakers. As for a preamp magnifies low level signals. But what is the actual advantage of them, and and how they correspond together.

[Resident Loser]

...understand those basics, there really isn't a whole lot more to be said...it's all basically a step-up procedure to bring the output of one device to the minimum input requirements of the next...

jimHJJ(...if you really want specifics, I'd suggest a visit to the library or a Google on amplifier theory...)

[topspeed]

I'm unsure I understand your question. Are you asking for the science behind each unit or what their general purpose is? An amplifier merely increases the gain from a source (cd, LP, whatever) to the speakers. A pre-amp is a switching station allowing the user to alternate between multiple sources. A passive pre will do so without adding gain, an active pre will add gain.

The idealogy behind separates is simple: It allows you to mix and match pre's and amp's to your liking. Manytimes, a company that makes great amps may not make the best pre's, and vice versa. Separates allows the user to tailor the sound to their liking.

[hermanv]

The pre-amp is almost allways where the volume control resides. Besides switching this is mostly the reason they exist..

Quick summary:
1. Source selector
2. Volume control
3. Other optional controls (balance, tone, mono switch)
4. Optional place to put the phono amplifier.

Active pre-amps also do an impedance conversion, i.e. high impedance in, low impedance out.

One reason passive pre-amps are popular is that if all you want is volume control no active parts are really necessary. You can make do with just a selector switch and a volume control circuit. Passive pre-amps usually have the smallest sonic signature because they do so little