Archive of the former Yahoo!Groups mailing list: MOTM

Wendy Carlos tinkered together a modular vocoder using modified stock Moog
modules for use on the "Clockwork Orange" soundtrack.

In her 'boxed set' notes on this instrument, bottom of page 89, she writes:

"...A special switch [on the Moog 914 Fixed Filter Bank, the filters for the
Synthesis half of the vocoder] can alter the phase of the stages, which is
the best situation for vocoding, but not neccessarily for the usual uses of
the 914..."

Does anyone know what this means?

Now, I sort of understand the importance of phase in decoding speech when
talking about the biology of the ear (the 'hairs' that get excited can
decode formants by phase-aligning to harmonics of the speech signal,
blah-blah-blah)...

...but in a vocoder, what is this all about? Squinting at the 914 photo, I
see a toggle switch that might be labeled "Norm / Alt Inv," so I'm
∗guessing∗ that maybe it would alter the phase of every other bandpass stage
180 degrees, but... what does that do? How does that help vocoding?


On a related note, what exactly was the Roland Vocal Filter? Anybody? I
believe JH built a clone of one, but I haven't been able to find anything
about the thing at all.