VP-330 (analog speech synthesis)

[Ken Stone]

The VP-330 choir sounds did sound pretty good, and this ultimately led me to
building a synth module based on the circuit in question.

The filters are a bandpass, a common design found even in linear databooks,
and  from memory there are two stages per filter to get the Q up. There are
seven filters in total, and four of these are used for each of the three
vocal settings, the input signal being mixed at various levels by simple
resitor mixers.

I've been feeding mine with rectangular/square waves or three octaves mixed
at various levels, and find that some settings give much better vocal sounds
than others. The female filter so far has not produced anything decent, but
the other two are pretty good. Positive feedback also helps adding a pretty
substancial punch.

The design was done entirely with common value components.

Ken

>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.
>
>2. Are there any recordings featuring the choir presets alone?
>
>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?
>
>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.
>
>I would appreciate any information on this subject. Thanks!
>
>************************************************
>*     Mark Smart                               *
>*     Electronics Engineer                     *
>*     NovaNET Learning, Inc.                   *
>*     smart at medusa.nn.com                      *
>************************************************
>
>
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                Ken Stone  sasami at blaze.net.au
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               <http://www.anime.net/~kens/>
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             <http://www.blaze.net.au/~sasami/>
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