Also confirmed that this particular PIO does fit when mounted behind the PCB :)

That's for C3, right?

Hey there,
I've been using my fet847 for a few years now and was very happy with it !
Today I wanted to replace its RK12 capsule for a Beesneeez K47 because I've always wished this mic had more mid presence.
But now the mic as very low volume so when I adjust gain for enough level I obviously get a lot of noise.
Adjusting the bias isn't helpful here.
I've checked & cleaned my soldering many times.

Any clues ?