that's a tough one. you'll have to use your lfos. attach a saw to the pitch, then adjust the amount and speed so that the pitch drops. then attach a tri to either the cutoff or one of the oscillator parameters. and raise the resonance so that it self resonates. that's what i can think of off the top of my head. there are different ways to make sounds like that. i think the oscillators should be triangle, triangle and triangle, triangle and sine, or triangle and square.