VP-330 (analog speech synthesis)

[Jim Shearer]

In message <199808052022.PAA03541 at medusa.nn.com>, Mark Smart
<smart at nn.com> writes
>This thread relates to what I have been curious about lately...the Roland
>VP-330 Vocoder Plus. I just found out that this keyboard had, in addition
>to a regular vocoder section, "choir" presets which were supposed to
>represent choirs of male and female vocalists singing "Ahhh". This was
>implemented totally in the analog domain using an organ-like divide-down
>network going through a bunch of static analog filters. This sounds to me
>like it could conceivably be really cool, but a have a lot of questions.
>
>1. Did these presets sound any good? I've never heard or seen this keyboard
>   in person.
...I messed about with one of these in the early '80's, I thought it
sounded great! Nice "Tomita" like choirs and strings.
>
>2. Are there any recordings featuring the choir presets alone?
...Tomita actually credits it in his later albums (along with a
veritable wish-list of other analog machines).
>
>3. What waveforms are going into the filters to make the sounds? How are
>   they derived from the square waves of the divide-down network?
...The original signals are square-waves from the divider chips, these
are then integrated (simple R-C-Diode), then filtered, then chorused (To
liven up an otherwise static sound).
>
>It seems to me that a setup like this has the potential to sound better
>than samples being played back at different speeds, since the formants
>would not move. This could avoid the chipmunk and Jabba the Hutt sounds
>which mulitple-speed sample playback create.
...A way often used to avoid this in samplers, is to take multiple
samples at various pitches, so the 'chipmunk' effect never gets too
noticable before the next sample takes over. (Logical extension is to
have a unique sample for every key (I believe some sample-based piano's
do this)).
>
>I would appreciate any information on this subject. Thanks!
>
>************************************************
>*     Mark Smart                               *
>*     Electronics Engineer                     *
>*     NovaNET Learning, Inc.                   *
>*     smart at medusa.nn.com                      *
>************************************************

--Jim Shearer jim at base.demon.co.uk