PRE-AMPs - questions

[admin_exported]

Hello All

Does anyone know how pre-amps work and do the improve sound quality that much?

Thanks

S.

 

[Tony_R]

Pre amps are almost always used with seperate power amplifiers.

For example, you wouldn't use a preamp with an integrated amplifier (unless it had the ability to seperate the pre and power stages).

So to summarize:

Power amps generally have an input sensitivity (for full power output) of 775mV (0.775v) and some 1V. mV = millivolts.

Integrated amps will have an input sensitivity of approx 200mV (for full power output) (full volume)..

So... the job of a preamp is to amplify (and provide volume control of) the signal from your source (CD Player / Tuner / DAC etc.) to a level suitable for a power amplifier.

Now the confusing bit...

Most CD Players and DACS already have an output of around 2V - which as can be seen, is double that required by the power amplifier.

This is where passive preamps come into play - as all they do is provide input selection and control of the volume - there are no active electronics within the device (hence the term passive!).

I hope this clears things up for you.

Tony.