Check Tiptop's Fold Processor out...very cost-effective. But if space is more of a concern, then West Oakland's new Sinulator (a six-fold wavefolder!) might be a better pick while still remaining relatively inexpensive. Also, eject the Doepfer A-148 dual S&H and look at their A-184-1 instead. In that, you get sample and hold, a slew gen, AND ring mod, all in a measly 4 hp!