From: META000 <META@UNB.CA>
Subject: Re: What to do with a vocoder?
Organization: The University of New Brunswick
Date: Thu, 19 Nov 1992 15:44:53 GMT

In article <Bxu7o3.HsI@cmptrc.lonestar.org> neal@cmptrc.lonestar.org (Neal Howard) writes:
>In article <1992Nov15.210746.17441@dragon.acadiau.ca> 880518l@dragon.acadiau.ca (Nelson Langille) writes:
>>I have a chance to get a vocoder VERY cheap,  What can be done with it that
>>is half normal.  Eg, can a chorus or flange or anything be produced.
>>
>>I want to run my guitar through it.  I also have a small keyboard that is
>>non-midi (not sure if that matters or not).
>
>
>You'll get the classic vocoder-type sound by using the keyboard (maybe a
>strings sound) into the "instrument" input on the vocoder and singing into
>a mike plugged into the "mike" input (remember the weird robot-like backing
>vocals in the Cars' "Dangerous Type" and the "Ahhhhhhhhhhhs" in the background
>vocals of the 10cc tune "I'm not in love" ???). A vocoder (I'm assuming you
>have the old standard Roland Vocoder?) to me doesn't sound much like a chorus or
>flanger but uses very similar technology to acheive it's effect. It feeds the
>"instrument" input through a bucket-brigade analog delay line just like a
>old fashioned analog chorus/flanger and the "mike/voice" input is used to
>generate an envelope with which to modulate the "instrument" signal. I can't
>remember if the delay time and/or regeneration of the bucket-brigade device
>are modulated by any part of the incoming signls or if they are fixed or
>adjustable from the front panel. By feeding in a slow sweeping long sustaining
>strings sound from the keyboard into the "instrument" input and feeding your
>guitar into the "mike" input, you might get some flangelike sounds. Experiment.
>--
>=============================================================================
>Neal Howard   '91 XLH-1200      DoD #686      CompuTrac, Inc (Richardson, TX)
>         "Let us learn to dream, gentlemen, and then perhaps
>          we shall learn the truth." -- August Kekule' (1890)
>=============================================================================
>.
>.
Vocorders are highly underutilized devices.  Although originally
invented for voice communication purposes, and exploited for voice
like sounds from instruments, there is a wealth of possibilities
under the hood, some of which are hinted at in Neal's comment.

Vocorders should be considered as general purpose timbral shaping
devices, with the shaping provided by some real-time reference
rather than "controls".  Given this, one can use the guitar itself
to shape the sound of the guitar.  For instance, by feeding the
guitar into a delay-line, and using the delayed output to modulate
the vocorder (i.e., "mike" input), the notes you are playing NOW
have their timbre shaped by the notes you played a moment ago.  Set
up the delay for lots of repeat, and you get a repetitive effect.

For even wierder and wilder sounds, go from the delay output to an
envelope-controlled filter (aka "auto-wah") and THEN into the
vocorder mike input.  What you get is filter effect that corresponds
to the force of your playing, but not exactly to the force of the
note you happen to be playing NOW.  Essentially a semi-random wah
sound.

How about this?  Tape household or street noises, or any random
sound source, and play the tape into the mike input.  Again, the
idea is that semi-random changes in timbre can be interesting and
inspiring.  Craig Anderton suggests things like taking a drum mix
and feeding that into the vocorder mike input as a modulating sound
source.  I have a little Casio M-10 keyboard (the original from 1982)
that has been modified to have infinite hold.  This allows me to
select one of the voices, hit a chord, and it stays on until I hit
another note.  If youhad something like that, it could be a useful
"preset" guitar voicing ("clarinet" tone, "organ tone", etc.).
Hell, you could even use those "demo" tunes on the cheap keyboards
(the ones that go on and on until you turn them off) as a modulating
source.

Use your imagination and I think you'll be endlessly surprised and
intrigued by the possibility these things hold.

Mark Hammer

Xref: sparky alt.guitar:10080 rec.music.makers.guitar:297