Interesting. I remember I once removed the 'good' membrane from a damaged U87 capsule and used it to repair another U87 capsule. In this case, the membrane was definitely glued to the tensioning ring. (Otherwise I would never have been able to reuse it again!) The repaired microphone sounded good after this 'transplantation'.Anyway: the owner of the microphone was very happy with the result.Although the capsule looked as an original Neumann one, there is of course a chance that it had been replaced with a third party one. Or could it be that after many years of use the membrane just sticks to the tensioning ring? (I would be surprised if this happens.)
Very interesting review! So again, the tensioning of the capsule membranes is the biggest problem.Could you unveil a little how it is possible to relax the tensioning of the membranes?(Not that I am even thinking about doing this myself!!!)As far as I remember, the membranes were glued to the tensioning rings.(Anyway, that is what I saw when I took a damaged Neumann U87 capsule apart.)
Heat could possibly decrease Mylar tension, but the problem in this case that is that it has gold bonded to it.
Heat could possibly decrease Mylar tension ...
Mylar is pre-tensioned or stetched during manufacturing. Depending on the tension used in the capsule it's more likely that heat will increase the tensioning.But - we do not know how Neumann treats the mylar in the manufacturing process.