I don't know much about genuine C12s, but I did buy a cheap'n'cheerful Chinese Avantone CV-12 - with generic 'sharp' no-bass Chinese capsule - and fitted one of Matthew McGlynn's 'Microphone Parts' RK-12 (C12-soundalike) capsules. (I don't know the source of his RK-12s.)
What a universe of difference! ..New mic! Well worth the $169. And he also supplies a build-it-yourself V-251 circuit. (But the great-sounding capsule was sufficient improvement for me, so I haven't tried his circuit board.)
I have no connection with Mic-Parts, and this isn't any kind of advertisement ..just a recommendation that his RK-12 capsule (whoever makes it) is well worth - to me, anyway - the (relatively) not too much asking price.
YMMV.
What a universe of difference! ..New mic! Well worth the $169. And he also supplies a build-it-yourself V-251 circuit. (But the great-sounding capsule was sufficient improvement for me, so I haven't tried his circuit board.)
I have no connection with Mic-Parts, and this isn't any kind of advertisement ..just a recommendation that his RK-12 capsule (whoever makes it) is well worth - to me, anyway - the (relatively) not too much asking price.
YMMV.