There's sump'n awful cool hidden in one of the dark spaces of menus on the beastie. In the pre-filter mix edit, on the very last (rightmost) page there's a "f1->f2" parameter which controls how much of the output from filter one goes into the input to filter two. You can get some really nastyhappy filter stuff happening like that, especially if filter two is one of the varieties that emulate filter-input overdrive ("rp lpf" and "mg lpf" if I recall correctly. The former is usually a little crunkier). Hoohaw.