since the Neumann OA10 is not mached for the high ratio input trasformers I have thought to change some components on it, just to have an OA10 clone usable for the 312 clone preamps.
Moreover, I have changed the old and discontinued BC212B, BC182B and all original diodes with modern BC560C, BC546B, BC556B and 1n4148.
I have made a protoype just electrically tested and measured.
Moreover, I have changed the old and discontinued BC212B, BC182B and all original diodes with modern BC560C, BC546B, BC556B and 1n4148.
I have made a protoype just electrically tested and measured.