Thank you for pointing out that the threads of the M 155 don't match those of the original M 221, which I wasn't aware of.
The question (for me) now is whether the threads of the original M 221 match those of the M 221 A. There's an indication in one Telefunken document that they don't--actually, a literal statement that the capsules of the original M 221 series can't be used on M 221 A amplifiers. But to me that statement seemed as if it could have been a warning not to do something that was possible, rather than a warning that to do it was impossible.
So I will try to find that out first-hand if I possibly can--I hate relying on hearsay. (For example, even though I knew that an M 201's capsule head couldn't possibly fit onto an M 221 A amplifier, I actually tried it, for the sake of being able to say that I had tried it.)
Until then, I think it's best if I scale back the first of the two messages that I posted yesterday. I don't want to create false understandings or false issues. I also removed what I wrote about errors in earlier messages, since obviously I can and do make mistakes as well, sometimes right out in public.
--In general I can only surmise why Schoeps made some of the decisions that they made in the mid-1950s or, indeed, at other times. I have a fairly long list of "Schoeps mysteries" that I would like to solve. And even though I do occasionally find real answers (or what seem like real answers), that list just keeps getting longer.
--best regards
