Newb; building an analog DIY rack - need advice on next module(s)

As $subject. The parameters are: DIY-only, analog signal only (I'm OK with digital control, depending), and trying to keep the per-module cost less than 100$US (flexible on that; kinda have to be :D)
Inverted panels represent DIY projects in progress.
Stylistically, I'm interested in drone/ambient/generative/random etc...

EDITED Apr 4th 2020, 04:26

Even though it's not DIY or pure analog, you might want to check this module out anyway. I just got one and it seems a perfect fit for the styles you mentioned.

https://www.modulargrid.net/e/4ms-company-spectral-multiband-resonant-filter

EDITED May 23rd 2017, 01:07

Even though it's not DIY or pure analog, you might want to check this module out anyway. I just got one and it seems a perfect fit for the styles you mentioned.

https://www.modulargrid.net/e/4ms-company-spectral-multiband-resonant-filter
-- Synnic

Oh lord, yes. I got to play with one at Modular Eight in Portland when I was there. Unfortunately waaay out of my price range (advanced hobbyist).