Next on the list is building great filters, both resonating High and Low Pass, voltage control is a must if I want this to integrate further on a CV controlled system.
I found this great component manufactured by Alfa and distributed by Electric Druid: the AS3320, a clone of the CEM3320 as featured in the Sequential Pro-One and the Oberheim OB-Xa. Check it out here:
https://electricdruid.net/cem3320-filter-designs/
This is a 4-Poles, 24dB/Octave resonant filter blocks that you can arrange in High, Low, and Band-Pass mode.
After a few errands on the breadboard, I finally got the High-Pass working:
Good audio here Hi-Pass Mode:
Audio w/video Lo-Pass mode:
Then I went for the Low-Pass and decided to solder that one on a perma-proto board from Adafruit:
and put it in a metal cakebox with big knobs on top:
It works great!