> Thanks again Florian. I'll have a look at these videos.
> By the way, do you know if this form of synthesis is in any way
> related to how the, much maligned, Korg Poly 800 generates its tones

The connection is that many techniques like these relate to organs and
to a fair extent generating oscillator different tone colors for the
least amount of money. A traditional VCO like Moog or Doepfer
generates a saw wave (Buchla went for a triangle) then the other
waveforms are shaped from it with other circuits. Interestingly
Bubblesound sells some of his shaping circuits separately as a module,
though he starts with a triangle like Buchla did. The pitch is
controlled by your CV. An accurate enough VCO is not cheap. What is
cheap is a circuit that makes just square waves. So is an audio
divider in comparison to another VCO.

For what it's worth using feet ( ' ) like 16' represents a lower
octave on an organ, but not as low as 32', which would be the octave
below. The example below says (") which is a typo, it's one mark (').
The terminology came from organ pipes. Twice as long = half the pitch
= an octave lower. Earlier synths like the Minimoog used to label
octaves that way, but his VCOs did not use dividers. Just mentioning
the use of feet measurements doesn't mean it's organ-like or uses any
dividers. It might just be vintage.

What you had on string synths and all electronic organs like the RS09
is you have a whole octave (12) of high frequency tone generators.
They are simple and run all the time. 12 sounds like a lot but they
provide the sound for every key in full polyphony because they can be
audio divided for the other octaves. Then on a string synthesizer
you'd have a single filter and a single chorus to fatten the sound. So
it's paraphonic, Roland's term for an electronic polyphonic organ with
monosynth style processing

I've never really studied the SH-3/SH-3A. I think it's a single square
wave VCO instead of taking a core saw waveform and making a square,
tri, sine, etc. out of it. Roland used an audio divider like the A-115
being attached. It's a 1 vco monosynth using dividers rather than
waveshaping.

The Poly 800 was definitely Korg's attempt to make a poly synth as
cheap as possible. They started with 8 digital square wave oscillators
and divided them down. Then they let you turn them on and off or use
the "stepped" relationship mentioned below to make a kind of saw
shape, though it's not a really the same as a proper saw waveform.
What makes it most maligned is that Korg used one filter instead of 8
to save money. The only good thing out of it I guess was that decades
later, that one VCF was easy to mod to do crazy feedback much to many
DIYers enjoyment. Had they used 8 of them the mod would still be
possible but much more complicated.

Nick

>
> It too uses the 16, 8, 4, 2 footages of square waves, which can be
> combined to evince a basic form of wave shaping. Alternatively, the
> same footages of close approximation of a saw wave can be used.
>
> Cheers,
> Alan
>
> --- In Doepfer_a100@yahoogroups.com , Florian Anwander
> <fanwander@...> wrote:
> >
> > Hi Alan
> >
> > unfortunatley my SH3a is parts and pieces at the moment: not in a
> > shippable state definitely ;-)
> >
> > Nevertheless these my give some ideas:
> > http://www.youtube.com/watch v=QuqWtlKZCYY
> > http://www.youtube.com/watch v=dJ4I5Tgxs8E
> >
> > Also the way Roland made string sounds in the RS09 might be
> interesting.
> >
> > They had four octaves of rectangle like the A115, mixed them in a
> relation:
> > 16"1,
> > 8" 1/2
> > 4" 1/3
> > 2" 1/4
> > then they filtered this in a highpass. This highpass output
> provides a
> > pseudo-saw as base for the typical Roland string sound.
> >
> >
> > Florian
> >
> > Alan schrieb:
> > > Thanks for the suggestion Florian. Do you think you could send
> me an SH3a so I can put it to the test ;-)
> >