OPA1612 as microphone pramplifier

[RuudNL]

In the updated schematic, the gain of the first OpAmp stage can be extremely high, with a feedback resistor of 1 M.ohm. (Depending on the drain impedance of the FET.)
The termination of the microphone capsule is low, with a resistor of 1 M.ohm.
I would think about a value of for example 100 M.ohm.

 

[abbey road d enfer]

@abbey road d enfer
I thought I could use DC-DC converter to isolate PC's supply noise and buzz.

I believe cleaning a power rail can be done without resorting to a DC/DC converter.

To everyone: I had to leave C1=50pF, when I increase it into 1n I got more input noise:

OPA1612 is a bipolar opamp, it is not optimized for such high resistance. Ideally R1 should be about 5-20 kohms.

+1 for increasing R0 to much larger. Typically 1Gohm is found here.