[sdiy] +/- 9v synth circuits / EDP Wasp Schematics?

[harrybissell]

If you Google for "top octave generator" you will find some info
on chips that will show you some divisor ratios.  You make a high
frequency VCO... and divide by these integer numbers.

The Wasp did this with a collection of discrete logic gates, you might
do the same with an EPROM or even a diode matrix to generate the
right numbers.

When I think of 'low power' I think of CMOS circuits... but watch out
for
the linear application of gates like the 4069 (Rene Schmitz et al...
:^)
because in that mode, they draw substantial power and you might be
better
off with a frugal opamp (power wise).  The Wasp filter uses CMOS in
linear
mode

H^) harry

Henry Till wrote:

> --- harrybissell <harrybissell at prodigy.net> wrote:
> > If I had to do a +/-9V synth... I would study the
> > "Wasp" synthesizer for ideas...
> >
> > I'd do a high frequency VCO with a programmable
> > digital divider...  now tuning
> > stability is not really an issue... all the notes
> > will always be in tune.  I'd
> > add the Wasp
> > filter and whatever else you like.  I would not use
> > voltage regulation at all for
> > most
> > of the circuits... possibly just some reference
> > voltage IC for the VCO
> >
> > I would not try and copy the Wasp's PLL trackers...
> > otoh if you need portamento
> > that would
> > be a way to go.  If you kept the HF-VCO quite high
> > in frequency... you could
> > locate the
> > PLL high up in the chain (higher freq. input will
> > make the PLL settle faster...)
> > For waveshaping
> > I'd use digital dividers and summing resistors...
> > maybe a 16 step staircase
> > instead of a sawtooth...
> >
> > H^) harry
>
> Sort of my first post here.  Hi everybody...
>
> Do you, or does anyone else know of any schematics one
> could refer to for such a design (a high frequency
> oscillator w/digital divider like the wasp)?  any wasp
> schematics? i can only seem to find the
> well-documented filter...
>
> I like the idea of a portable battery powered synth
> like the wasp...maybe i could build a separate box
> with some esoteric controllers, and run both off
> batteries for guerilla synth action (w/pignose or the
> like)...
>
> -Henry
>
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