Messed around on Thor and got something pretty close:
1. Two oscillators, medium width pulse waves (halfway between square and 0), tuned two octaves apart.
2. Key tracking 100%, set filter envelope sus to max, cutoff all the way down, then turn contour up until it sounds right.
3. Filter envelope attack 70 ms. Release max
4. Amp env release 350 ms
5. Bump up the resonance a bit to add a little shape.
The pitch itself is between a G and Ab (analog synth?) bouncing around 2 or 3 octaves.
- Interactive Synthesizer Training Software