Help needed with Neumann BV12 transformer

[skidmorebay]

Hi folks,
I bought this modern Neumann BV12 transformer on the Black Market here. I'd like to install it in place of the AMI T67 I have in one of Poctop's D-U67's I built.

I'm having some trouble figuring out the leads. In the upper photo below, going counter-clockwise from the top, I'll call the wires:
Green1
Brown1
Yellow
Brown2
White1
Green2
Black1
White2
Red
Green3
Blue
Black2

I went methodically through them all and found these connections with my ohmmeter:
Red to Green3: 953R
White1 to Brown2 46.3R
Blue to Yellow 23.9R
Green1 to White2 25.6R

The four remaining wires show no connection to any other wire. Should I assume the transformer is damaged?

From what I found, I'm assuming that Red to Green3 is the upper pair of primaries in the original U67 schematic (below), White1 to Brown2 is the upper pair of secondaries, and blue/yellow and green/white are the middle pairs of secondaries.

This transformer has twelve leads, just as in the original schematic, so I assume there aren't any internal connections I'm missing.

Can anyone offer some advice on how to figure out which leads are which, or if this transformer is dead?

thanks much,
Justin

 

[rock soderstrom]

Hmm, I count 13 leads in the original schematic. The photos show only 12. There is a additional black in the photo, but I am missing one white and one red. Strange...

I guess you know that, but just to be clear.

rt=rot=red
gn=grün=green
sw=schwarz=black
ws=weiß=white
br=braun=brown
bl=blau=blue
ge=gelb=yellow

 

[skidmorebay]

Yup, Google Translate helped me with that...

I was a little confused about the black wire. I was thinking maybe it was a case shield drain wire. I emailed tech support at Sennheiser (who owns Nuemann now). They told me that the wire colors should all be the same as the original. But, apparently not.

 

[Moby]

I prepared this connection scheme for installing my transformers who are hiatorically correct and compatible with the vintage U67. Feel free to use it. I hope it helps. Cheers

 

[skidmorebay]

I prepared this connection scheme for installing my transformers who are hiatorically correct and compatible with the vintage U67. Feel free to use it. I hope it helps. Cheers

Moby, thanks a lot for putting that schematic up here! I guess I didn't get notified of your reply. I just saw this now, a year later, when I am finally getting around to installing this transformer! This was very helpful.

 

[SparkleBear]

Moby, thanks a lot for putting that schematic up here! I guess I didn't get notified of your reply. I just saw this now, a year later, when I am finally getting around to installing this transformer! This was very helpful.

Bump, that schema post helped me so much when I was doing the traffo swap on the ioaudio mk67 system about a year ago. It was a great upgrade! Glad you’re getting that lovely transformer into your build

 

[skidmorebay]

Indeed! I would love to find another one.