Electronotes and Synth-DIY CD

[tomg]

Hi Juergen, Terry

I think we can safely give Terry credit. I remember seeing the NS
app note. The original VCO from NS looked more like the one
Moog used in the Sonic6. The Sonic6 appeared in 1978. The
Taurus was the first Moog I saw with Terry's topology and  that
didn't come out until 1979....

Tom



> Message text written by Haible Juergen
> >o Terry did really invent the topology of this saw VCO, and Moog,
> Buchla and Serge got it from EN ?? This is not a rhetorical question,
> and in no way a flame, it's really historic interest. (And I'd love to
> give Terry the credit when I'm discussing this VCO that almost everybody
> used.)<
>
> Hi Juergen:
>
> My recollection is I did invent at least part of this circuit, invention
> defined as creating a new circuit topology, in contrast to copying an
> existing circuit but changing part values.  The CCO core was mine, as best
> as I recall, as its been around 27 years since I did the design.  I had
> designed and built several different VCO's previously, mostly with
terrible
> performance.  Eventually I arrived at using an integrator, reset as fast
as
> possible with a FET.  The basic elements of this design, such as the
> integrator and threshold detector, were probably found in the January 1972
> edition of "Linear Applications"  by National Semiconductor, and some
other
> books I was using at the time.  I put these elements together into an
> oscillator that worked surprisingly well.  On the other hand, the
> exponential conversion section was mostly borrowed from somewhere,
probably
> the Minimoog, although Linear Applications also had a detailed analysis
and
> design examples of exponential and log convertors, which certainly was
> helpful.
>
> I will look through my archived files in the next few days and try to
> confirm this information.  It is possible I am remembering this
> incorrectly, and the CCO circuit was borrowed from somewhere, but I'm
> almost certain it wasn't.
>
> Some people have wondered about the name Terry Mikulic, as found in EN.
> That is my family name, which I changed to Michaels when I started a
> business around 20 years ago.
>
> Terry Michaels