using STAIRWAY from Squinky Labs, 2 VCOs from Bogaudio and Befaco’s RAMPAGE.
Plus some scopes to show the resulting waveform.
VCV Rack controlled with Midi Fighter Twister:
Encoder 13 controls FM of VCO1, whose SAW goes into FM of VCO2 and cutoff (CV1) of STAIRWAY filter.
Encoder 15 into RISE CV of RAMPAGE, which in turn goes into cutoff (CV2), V/OCT and PW of VCO2, the VCAs and the PAN of the mixer.
Encoder 14 controls the amount of RAMPAGE into V/OCT of VCO2 (attenuverter offset).
Pressing push-encoder 10 triggers RAMPAGE. Push-encoder 5 switches RAMPAGE between 1 shot and cycle.