Osc 2: Medium Pulse Wave, same Octave and Volume as Osc 1, but bump up its Fine setting just a little bit to get a little smear on the sound.
Filter: Bring the Cutoff down to around noon to get that nice round sound. Turn off Keyboard Control as we want the really low notes to be a little brighter than the higher notes. Then you want to drive the filter by turning the External Input switch to the middle position, and turning up the External Input Volume to around 2, and turn on Soft Clipping. Now the sound should be saturated and a little driven.
Filter Envelope: This will add a subtle attack transient. Just bump up the Contour a little, set the Sustain to 0, and the Decay around 3-400.