SONY ECM-MS957 Stereo Microphone - Balanced Operation
Bringing my old ECM-MS957 stereo mic back into operation on discovering that it can operate in a true balanced mode, and will tolerate phantom power (even though it doesn't use it.)
*UPDATE 8 Sept 2022* Googling again for the service manual threw up a better scan that included the schematic diagram. This confirms that the MS957's MS-XY matrixing is done with the transformers that also serve to provide balanced outputs. By contrast, the cheaper Sony MS mics (MS-907 and MS-909) have no transformers, doing their matrixing with transistors, resulting in single-ended (unbalanced) outputs.