This time a voltage controlled all pass filter, which is good for... what? You'll find out. My next Kosmo format synth module.

00:00 Silent demo
00:10 Intro
00:20 What's an all pass filter?
01:30 Phase shifts
03:02 What phase shifts do
06:23 Circuit design
09:40 Demo on the scope
12:31 Demo: VCO modulation
13:44 LM13700 issue
16:15 Wrapup

Schematics, KiCad design files, Gerbers, and documentation in the repo: https://gitlab.com/rsholmes/vcapf

Blog post: https://analogoutputblog.wordpress.co...

Schmitz MS20 filter: https://www.schmitzbits.de/ms20.html

Breakouts to use SMD LM13700:
ChipQuik PA0005 https://www.digikey.com/en/products/d...
ChipQuik PA0005C https://www.digikey.com/en/products/d...

Music: Ringtone by Rich Holmes