I am thinking about something I never thought I would: A phase splitter.
It would be used in a FM radio stereo decoder. If my conceptual idea works, I would need two identical phase split signals from a single signal. Ruler flat amplitude and 0 degree phase 30Hz to 15kHz, 0dB gain, reasonably low output impedance being able to drive LC low-pass and notch filters, 1V - 2V maximum output.
There are some possibilities: differential tube stage, the usual one tube splitter taking signals from cathode and plate, tube with a small interstage or phase splitting choke, ... (I am a bit worried about IT and choke phase responses).
Any suggestions?
TIA,
TonB