So the "organic quality" of a possible 259 expander depends also on
any (im)perfections of the triangle source that goes in

regards
Joost

--- In Doepfer_a100@yahoogroups.com , Bakis Sirros
<synth_freak_2000@y...> wrote:

>
> --- Dieter Doepfer <hardware@d...> wrote:
>
> > From: "Dieter Doepfer" <hardware@d...>
> > To: "Bakis Sirros" <synth_freak_2000@y...>
> > Subject: AW: 1 Re: New poll for
> > Doepfer_a100
> > Date: Fri, 6 Aug 2004 12:48:48 +0200
> >
> > > -----Ursprüngliche Nachricht-----
> > > Von: Bakis Sirros
> > 2
> > > Gesendet: Donnerstag, 5. August 2004 21:01
> > > An: Doepfer_a100@yahoogroups.com
> > > Betreff: Re: 1 Re: New poll for
> > Doepfer_a100
> > >
> > >
> > > hello psm,
> > > i don't know that yet.but,i guess that you'll have
> > to
> > > only connect the triangle output of the a111 to
> > the
> > > expander module via a normal patchcable.dieter
> >
> > right. Probably only a patch from triangle out to
> > the waveshaper module.
> >
> > The suggested "A-111 expansion module" will of
> > course not only work with the
> > A-111 but with every VCO that has triangle waveform
> > available.
> >
> > The main difference - as mentioned earlier by other
> > members - between the
> > Buchla design and other VCOs is the triangle core,
> > i.e. the basic waveform
> > from which all other waveforms are derived is
> > triangle - in contrast e.g. to
> > the Moog VCOs, SSM2033 or A-110 for which sawtooth
> > is the basic waveform.
> > For triangle VCOs normally a bipolar current source
> > (so-called Wilson
> > current mirror) is used in contrast to unipolar
> > current sources for sawtooth
> > VCOs. The CEM3340 also uses triangle as basic
> > waveform. So from my (so far
> > theoretical) point of view using a CEM3340 based VCO
> > will have no
> > disadvantages compared to the original Buchla VCO
> > core as the tracking of
> > the A-111 is much better. Maybe there are details I
> > have overlooked but I
> > don't think so.
> >
> > Waveforms derived by waveshaping circuits from
> > triangle resp. sawtooth will
> > sound a bit different. One of the "problems" with
> > sawtooth as basic waveform
> > is that the saw reset is not immediately but takes a
> > few microseconds as a
> > capacitor has to be discharged. Consequently all
> > waveforms derived from saw
> > will have a short spike at the reset position of the
> > saw. For waveforms
> > derived from triangle this peculiarity does not
> > appear as only the
> > charge/discharge direction at the bottom/top of the
> > wave has to be changed
> > and consequently the spikes mentioned above do not
> > occur.
> >
> > But the VCO core and the waveshapers are two
> > different sub-modules. So why
> > not combine the Buchla waveshaper with triangle or
> > sawtooth based VCOs. This
> > is why I advocate for a separate Buchla type
> > waveshaping unit as it probably
> > could be combined with any VCO that has a triangle
> > output available. If a
> > triangle based VCO is used (e.g. A-111 or any other
> > CEM3340 based VCO) the
> > sound should be very close to the Buchla VCO from my
> > point of view.
> >
> > Best wishes
> > Dieter Doepfer
> >
> >
> >
>
>
> =====
> Bakis Siros
> Parallel Worlds / Polariton
> Athens-Greece
> 1 group owner
> http://www.shimarecords.co.uk
> http://www.ward12.com
>
>
>
>
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