The CV Twister is a Grant Richter circuit adapted from the Sandin Image Processor. The original circuit was used to give "solarized" effects to video signals. With some redesign it also makes a nice low parts count control voltage twister / wave warper circuit for audio. The bandwidth is limited by the op-amp type, and should extend above 20 Khz with this design. The sections could also be 3/4 of a quad op-amp. The 5.1K resistors and 10K pots could also be 47K or 51K and the pots 100K. The higher current of the 10K makes the breakpoints a little sharper, but it should still work with the higher resistances.