more VCO cores

[Haible Juergen]

Speaking of EN celebrities and VCO cores:
Yesterday I ran across a 3080-based triangle HF-VCO
from Ian Fritz again (Used to clock some ROM tables etc.).

There was this note about using exactly the right 
input voltage step for the 3080, although the OTA is just
used as a current *switch* rather than a linear multiplier.
Too high or too low voltage would cause tracking nonlinearities.

I'm asking because I've run into the very same trap myself
(sort of reinventing a "broken wheel"): I thought the best
would be to overdrive the OTA input in order to avoid temperature
dependence of the output current. But I've encountered the
same tracking problems. I did not find a solution.
Ian *has* found a solution, but the article says he didn't exactly
know *why* a certain level works and others do not.

Is the mystery solved meanwhile ?

JH.