Voltage Controlled Waveshape (was animation (was Re: [sdiy]Imperfect VCO)

John Loffink jloffink at austin.rr.com
Sun Aug 3 05:35:24 CEST 2003

> right, but Don's are simple crossfades between 2 things, or on the 259
> there are several CV ins to control several parameters, HOWEVER, what
> am refering to is sweeping accross several more or less unrelated
> with one voltage. That can be done with the interpolating scanner, by
> putting whatever signals into the inputs.... however in this case it
> all waves from the same VCO that it's hardwired to.

I believe Wavemakers was the first to interpolate between VCO waveforms,
in the 652 Dual Voice Subsystem:
http://www.wavemakers-synth.com/652pg1.html, in 1980. In Wavemakers
parlance this was a "lap circuit," short for overlap, much like the J.
Haible scanner circuit.  This was used earlier in the Wavemakers Triple
Bandpass Filter: http://www.wavemakers-synth.com/308pg1.html, mid 1970s
time period.

> My guess, and it is only a guess, is that the Serge NTO was an attempt
> to have the possibilties of the Buchla 258 plus something more in it's
> waveshaper. That's why they have the sine between the saw and square.
> Then you can set it up to sweep from sine to either, so it can be set
> as either of the 2 oscillators in a Buchla 258. Which had already
> to be a valuable resource. You'd have to be really careful with the
> voltage so you don't "oversweep " though.

Just to be clear, the Serge NTO does not use a scanner type circuit,
rather the waveform is morphed through waveshaping to approximate the
sine, square, saw and pulse waves.

John Loffink
jloffink at austin.rr.com 

The Microtonal Synthesis Web Site

The Wavemakers Modular and Integrated Synthesizer Web Site

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