From Haible_Juergen#Tel2743
Sent Fri, Mar 24th 1995, 01:27

>   VCO that locks to an external audio source with a PLL

There was a DIY with a PLL-VCO and 16 sliders for waveform
control in an ELO issue in the 70's.
Doepfer did a sound-sampler with a PLL for a HF (clock)
VCO, many years ago.
The Portamento problem shouldn't be as bad as the problems
with conventional f/CV conversion, however.
Problems are some kind of unintended Portamento and
problems with modulating a locked VCO.
I'd like the idea of a PLL with a precise VCO and a S&H that
can open the loop, as soon as the frequency is stable, to add
modulation and stuff then.