When Neumann separated from the Telefunken based distribution, they also ventured into audio consoles. Most Neumann designs are quite different from the rest of german circuit design, making them quite unique is sound, but also in repair that ends up in problems 90% of the time.
Neumann made most of their x-former in house and building quality was not as good as the rest of the german companies, even their microphones are top notch...
The late black face 4xx series tried to take over the german broadcast market after Telefunken closed and Siemens shifted interest into digital developments, very nice but also hard to find parts, etc...