Info requested on EMS Phase Frequency Shifter

[Sean Costello]

Hi everybody:

Does anyone out there have any details whatsoever on the EMS Phase Frequency
Shifter?  I know that it was also included in the Vocoder 5000.  I have only
heard a little bit of tantalizing info - that the same circuitry is used
both for phasing and for frequency shifting.  Anyone ever use one?  Better
yet, anyone have schematics?  It would be cool to see if the circuitry is as
weird as the other EMS gear I have seen or have heard about.

Thanks,

Sean Costello

P.S.  Anyone have Synthi Hi-Fli schematics out there?  I'd like to see how
diodes are used for voltage-controlled phasing.

P.P.S.  Anyone out there know of any good digital frequency shifter
techniques? I'd like to work on making Csound do this, but apparently the
Hibert transform is difficult to implement in a successful manner digitally
for this effect.