[sdiy] VCF caps in modern synths

[Mattias Rickardsson]

Den sön 28 mars 2021 15:53 cheater cheater <cheater00social at gmail.com>
skrev:

>
> The sound quality you're talking is "roughness" and is measured in Aspers.
>

I've never heard of aspers before, but it seems to refer to modulation in
the lower audio frequencies (20-300 Hz) rather than harmonic distortion:
https://community.sw.siemens.com/s/article/sound-modulation-metrics-fluctuation-strength-and-roughness

Tiny capacitors have a very large voltage gradient across a very short
> casing. They're probably self-modulating, i.e higher voltage means
> less capacitance. Essentially self-filter-FM.
> ...
> Fully-balanced synths anyone?


Moog ladder filter? (-:

But since the self-modulation goes in the other direction for negative
voltages, a straight-up balanced design wouldn't help much.

One more option is to add self-filter-fm cancellation to your filter,
> and have it as part of the tuning or calibration procedure.
>

Some research into the nonlinearities would be essential. Or why not go for
C0G instead. :-)

/mr
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