[sdiy] VCO Jitter, Slop ... (was: Re: Smith's Evolver Desktop's spikey VCO waveforms)

[cheater00 .]

Hi Andre!

On Mon, Jun 10, 2013 at 6:57 PM, Andre Majorel <aym-htnys at teaser.fr> wrote:
> I experimented with modulating the
> frequency of an MS-20 VCO with white and pink noise. As the FM
> sensitivity knob was turned clockwise, it went from no audible
> effect to unpleasantly warbly. I couldn't find a setting that
> made it sound "even fatter" or anything like that.

I strongly believe that this is because you haven't band-limited the
input noise. I wonder if you would like to try it and see if it helps?

Thing is, you'd need a special low-pass filter, which would let you
precisely dial in frequencies between 0.01 Hz and 0.5 Hz. Maybe
swapping the capacitors (for much bigger) in an existing design could
help.

Maybe a simple two-pole non-resonant RC filter could be built. Those
have minimal parts count.

Cheers,
D.