Pre-amp circuit design

[Besto]

This is a pre amp for mic.
Can anyone explain its working.

 

[KlausST]

Hi,

What exactly do you need to know?

It's impossible to explain the purpose and dimensioning of each single component....and the combination of them.

Basically: Q2 is the voltage amplifier, Q1 is the current amplifier.

 

[Besto]

Thankyou for the clarity.
I also want to know what is the purpose of R3,R6 and C6 in this circuit.

Also to reduce voltage gain what should I do.

 

[KlausST]

I also want to know what is the purpose of R3,R6 and C6 in this circuit.

It´s a mic amplifier, thus all I can say for now: It looks like a filtered bias supply. Not useful for every type of mic!
May cause a lot of popping sound when you connect the mic.

****

Gain can be adjusted by manipulating the feedback. This is the circuit that feeds the output of the amplifier back to it´s input. Mainly by: R10, R13, R11.
To reduce GAIN, reduce the value of R11.

****
A comment to the ciruit at all.
There´s nothing wrong with it. But a lot of components for poor sound quality. High power consumption (low battery life), generated heat, noise, distortion, big in size, a lot of wiring.
I personally would choose an OPAMP circuit.

Klaus

 

[Besto]

Thankyou.