Sure, it was relatively simple to the best of my memory…
Essentially it is a scream-y self-oscillating filter (Malekko Dual Borg) running through another filter to tame it, into a mixer which is multed and fed back into itself. Then sent through a Z-DSP reverb, where the feedback is naturally overdriving and adding yet more saturation. Just for good measure, after sending the signal to my external mixer, I think I routed the FX send from that back into my case and the internal mixer.
Then it was just a matter of feeling out the variables I’d given myself: self-oscillating filter cutoff frequency, subsequent filter cutoff, “dry” and “feedback” channels on the eurorack mixer, and the FX send level on my external mixer. It was kind of a game of allowing just enough feedback to keep the whole thing going, without letting any one part clip to the point of pure harsh noise. The modules themselves did a lot of the work as they interacted in complex ways and I think the reverb was the secret weapon in keeping it pleasant, as it rolls off nicely.