Jean Marie MATHIEU wrote:
This is very interesting

http://www.gefell-mics.com/capsules.htm

Who, except Gefell, make non mylar gold sputtering capsules ?

Nobody else. PVC has poor long-term stability, which is why Neumann gave
up on it years ago. But, there are folks who still like the sound and can
live with the inconsistency and maintenance headaches.

Most U47s today have been reskinned with mylar, because the original PVC
failed. This changes the sound (and many folks love the sound of the
U47 with the brittle PVC diaphragm that is about to fail, too).

What is the technologie of the Schoeps, Neumann, Josephson etc. and why ?

Almost everyone today is using mylar diaphragms with some sort of metal
sputtering. Mylar is light, consistent, and stable.

Gefell, and some of the measurement microphone people, make a few capsules
using very thin nickel foils, with no plastic backing. Schoeps also did
this in the 1950s but no longer does. The original technique for this dates
back to the Western Electric 640AA.

A small American manufacturer whose name I won't mention is using aluminum
capacitor foil for a diaphragm. This has a very high mass and results in
poor high frequency response.

These are the only exceptions I know of.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."