[sdiy] r/c phase shift on face (esoterica could save the pie)

[Anthony Bisset]

constantly humbled i am (not that i thought i knew anything)
i now understand how a r/c filter works... hahahaha

okay, but that'll only get me a phase shift amt that varies with
frequency which is way to complex for constructing an audio terrain
without dsp or autism.  so, back to coils and other such tricks.

so my question is narrowed.  how can we throw the phase of a
signal 90 degrees without it changing based on the a/c's frequency?

-glasnost