[sdiy] 4-pole SVF theory

[karl dalen]

Tom!
At the end of the day it's all about the "sound quality".
A 8 pole TR ladder sounds awfully muffled and damped.

Only insane people uses academic correct calculus to design
analog particular using 5% tolerances and diode ladders. :)

Very few can actually calculate forward nice sound.

Neils 3pole sounds lame, and i was disappointed that
mine sounded lame.

KD (no im not provoking).