It's a detuned sawtooth patch, but it's also a pulse width modulation patch. At first I thought I would have to add an inverted sawtooth oscillator or negative gain to pull off this classic trick, but then I realized that I could do the inversion with the waveshaper. I felt very clever when I did that, and then I added some modulation to the waveshape at attack time so that you get a blast of sawtooth followed by the PWM timbre.