Hi. I have three different types of Neumann NKMu power supplies for KM56 mics and none of them match the one NKM schematic I've found.
One version has the Stabilyt cells and a tube, one has a completely different pc board with a big power transistor mounted on it, no tube and no Stabilyt cells and the third version has a different board with small "plastic" board underneath with what may be a wirewound resistor with a couple of taps to maybe adjust the heater voltage.
Up top is a small pc board with three caps, some resistors and maybe a Zenier diode mounted to the transformer with a metal strap. I'm in search of schematics for these and any thoughts anyone has.
Needless to say the three units with Stabilyt cells are all corroded and the cells and plastic mounts are broken.
Thanks.