Gain Issues in Electret Mic Preamp

[rezydent]

I have a little problem, with this the amplifier , strengthening is only 2x
Is everything in this diagram is ok?

 

[FvM]

Doesn't look like a electret mic amplifier at all. Please clarify the circuit purpose.

 

[Audioguru]

The AD820 opamp has a gain of 11 times and the TL071 opamp has a gain of 10 times for a total gain of 110 times.
The Twin-T notch filter between the opamps cuts 52Hz to 1/50th.
Then 52Hz is amplified by 2.2 times.

 

[betwixt]

Yes, but it still doesn't look like an electret mic amplifier!

More like some kind of inductive pickup with a 50Hz mains power notch filter.

Brian.

 

[Audioguru]

Maybe the electret mic has its own power source and is connected to this preamp using ordinary wires instead of shielded audio cable so the wires pickup mains hum.