BS Automata

Bass stab sustain @ 0:44 in Metrik's "Automata" here

Ive tried putting it together myself but really just feel like I'm missing something.

Approach so far has involved having one oscillator (Osc A) set to a square wave and its level muted, with half window sync enabled to create some movement, and then having another Oscillator (B) just running a sine wave at -1 Oct, taking the output of Osc A and modulating it into Osc B. No luck :(