Sv: [sdiy] Digital VCO update

[Gene Stopp]

Hazy distant memory tells me the hypertriangle was devised to drive the
frequency of a linear high-frequency clock (like a 4046) in a BBD flanger,
and since the triangle was the only moving CV source, it was easier to warp
the triangle than add an expo converter to the oscillator. I seem to
remember that the triangle was generated by a CEM3340 and warped by feeding
the tri output back into the CV input.

Back when 3340's were cheap, of course.
 
- Gene

Achim wrote: 

I've been wondering about this: the hypertriangle controls a phaser 
which means the notch/pole frequencies, right? Is this frequency 
control linear or exponential and if it's linear is this not just an 
argument for having an expo converter in front of them to make the 
sweep constant speed in musical intervals rather than frequency?

> I don't know if an inverted hypertriangle would also be useful (start
> ramping up fast, then slow down as you approach the peak).

You mean a (compressed) sine? :-)