It appears that Effect #7 under Tech Effects named Tech Modulation

Does a pretty good impression of a Self Oscillating Filter,

Selecting good values for the Pre Mod HPF Cutoff, and the Mod LPF Cutoff, and a good value for
Mod LPF Resonance has the ole Self Oscillating Filter sound.  A quick test is to set the Dry Wet Balances to completely Wet and listen to the Filter Oscillate!.  And messing around with the Feedback really seals the deal.

It may not produce the exact same tone as the old Analog synth, but its close enough
And far more flexible!!!  :-)

And for those who know what to do with a Self Oscillating Filter have fun!