Hank Dussen said:I've finished my C12 a while ago but it really lacks some highs compared to some other microphones I have build (EF47, U67, U47,...), while I understand that it should be a rather bright microphone.
I've build it with the best parts I could find (Tim Campbell capsule, 5 star 6072 tube, AKG transformer) so I'm guessing it might be the caps.
I used an 0,4uF PIO k42y-2 for C12, and what I believe are 4000 pF polystyrene caps for C10 and C11. These caps have a marking that says RUWEL 4000/10 500v.
And parallel with these 2 caps, as well as for C13 I used 1000 pF polystyrene caps. These are marked 1n0 F250 V9KS.
Maybe some of these caps are wrong?
Anyone any idea what could be the problem?
Hank when is the capsule from?
I hate to ask this but it actually happened once. You did remove the covers from over the membranes?