raising output on fet based LD mic

[andre tchmil]

I have here two of those typical chinese LD condensator microphones, fet based.

One of the two is producing a 4-5 db less output.
I was wandering if I can mod this one to give it more or less the same output as the other one.
I see some G and M resistors in it .
Maybe someone can point me in the right direction where to mod.
i'm afraid, I can't post pictures of the inside, no camera at hand

 

[gyraf]

Could be due to capsule tolerances/differences? Try switching the capsules between the mics to find out.. If so, there's not much to do, other than maybe lowering polarisation voltage in the loudest one to match output of the lower..

Jakob E.

 

[zebra50]

Are the circuits the same? Are the transformers the same ratio?

 

[andre tchmil]

thanks Jakob.

 

[Gus]

what china circuit?