FET opamp for condensor microphone?

[Svart]

I see that the reply I did a few days ago in no longer here so here it is again,

Anybody have a comment about the output trafo? It was suggested that I use a matching trafo..

 

[mhelin]

I bring up this thread because saw a circuit (though not a head amp) which used TLC271 (CMOS) unity gain buffer but which was bootstrapped (10M + 10M to ground in positive input, feedback from output via 1 uF + 100k resistor to the joint of 10M resistors) and had an input impedance of 1G (with the AC input, when no input the Zin was 20G). It was powered from +/-5V and used 3 mA current. Any problems with that kind of circuit as mic head amp? Can you avoid using the 1G resistor in this case (maybe not as the circuit was still AC coupled with 100 pF cap)?

(please put this thread to Mic Meta ...)

 

[gyraf]

(please put this thread to Mic Meta ...)

Mhe,

The Meta's work by users like yourself suggesting relevant links to the Meta. Simply post a comment/answer in the meta in question - pointing to whatever you find might belong there. Then at some time, the Meta Keeper will decide if it belongs into the meta, and add it to the reading list...

Jakob E.