Electronotes and Synth-DIY CD

[terry michaels]

Message text written by Terry Michaels
>Hi Terry,

thanks a lot for clarification, both the circuit details and your name.
So without having the circuit in front of me, as I see it it boils down to
two important parts of the VCO:

Using an inverting opamp integrator (rather than capacitor + high
impedance follower), and
Using a FET for discharge rathe rthan a BJT.

Which is quite impressive indeed - I used to think one of the big
synth companies had introduced that. So the rather have all
copied that.
Just out of curiosity: Did you get any royalties from anybody, and did 
you have protected the circuit in any form ?

Best Regards,
and proud to have you here on synth-diy  8-)

JH. 
<

Hi Juergen:

I did not get royalties of any sort.  I had an odd experience at a NAMM
show in the early '70s when I visited the booth of a new synth
manufacturer, I think it was the "Cat" synth.  The saleman introduced me to
the company engineer, and after talking to him for awhile he showed me the
schematics of the Cat synth.  I noticed the expo section of the VCO was
identical to the VCO I submitted to Electronotes, although the CCO section
was different.  When I tried to tell him that I designed that circuit, and
he had copied it, he just blew it off, I'm sure he didn't believe me. 
Later I saw the same general design show up in the Minitmoog, so I guess it
got around.  I never thought of trying to protect the stuff I was doing. 
In fact I gave a lot of good circuits away by sending them to EN.  At that
time, I had no thoughts whatsoever of going commercial with any of this, I
was only building a modular synth because I loved what a synth could do, I
thought the Moog modular was the ultimate example of a synthesizer, and I
was basically trying to create a clone of a Moog modular, but using my own
circuitry .  I  was too inexperienced in commercial manufacturing to know
what was involved in patents, etc. 

Terry Michaels