Take one each of Encore Universal Envelope Generator (UEG), Encore Frequency Shifter (FS), Catgirl Synth Synthacon VCF, MOTM 390 LFO, and a CV Mixer. The core idea is the UEG excites the VCF. Patch the TRIG output from the UEG into the VCF Bandpass input. Set the UEG for cycle mode. Patch VCF through the FS. Both LFOs in the 390 modulate the FS frequency. Mix the LFOs, since the FS has only one CV input and it responds only to positive voltage. Add dual echos with MPX-1.
Twiddle: FS frequency (the big knob), FS frequency CV level, FS Feedback, VCF frequency, and the loop toggle switches on the UEG.