Neumann M150 - what tube type?

Hi Folks,

as an owner of several M150ies I would love to know what tube type is used in the microphone, as they are not too long lasting, and having them replaced by Neumann is quite budget consuming.

Unfortunately, there are no markings on the tube itself.

My mic tech got a replacement tube from Andreas Grosser (also not really cheap , which, unfortunately, was painted black...

Recordinghack claims that it is a 6111, but this would be a pentode with a round bottom.

It is a miniature triode with a flat bottom, I would guess of russian provenience.

Any ideas?

Thanks

Georg

Dear Georg,

are you sure that this M150 had installed original tube,  wasn't modified before?
M150 which i saw had 6111, which is double triode.
Even here you can see it:
https://www.gearslutz.com/board/attachments/remote-possibilities-in-acoustic-music-and-location-recording/138960d1254883662-426-4006-m150-mk21-shootout-piano-p1000486.jpg

Tube from your pic looks exactly like 6s6b, single triode. Even there's arrow marker on the bottom of the tube.

Original tube in the M147, M149 and M150 is a 6111 (dual triode, two halves in parallel).

Russian one should be 6Н16Б

It seems that Neumann used different tubes during production.
Today I had an M149 microphone for repair.
In the past, the M147 and also the M149 used a 6111 (double triode) tube.
But this mic had a 5-wire tube, clearly a single triode.
According to sources, the early batches used a 6S6B Russian triode.

Moby said:

Russian one should be 6Н16Б

Click to expand...

Exactly. I have used 6n16b-v dual triodes in parallell before. Did wonders for my build. Great tubes, crazy cheap.