[sdiy] 2164 SVF sound/noise?

[Olivier Gillet]

> The virtual ground is not an issue.  It simply represents a slightly
> different route for current into the filter cap.

Yesterday I changed the topology of a LM13700 based 4-pole filter from
"cap to ground + buffer" to "cap in the feedback loop of an op-amp".
This second configuration is indeed similar to what could have been
used for a SSM2164 4-pole LP (drop a resistor at the input and add the
"stability R/C pair" instead). I did not notice anything changed in
the sound in the change of topology (besides the added stability). So
the virtual ground requirement looks like a non-issue to me.