on a MIDI controller with a "Depth" value of 1200 cents (to tune the whole keyboard up or down by an octave), and assign "Src2" to be modulated by "LFO1". Further, the "MinDpt" and "MaxDpt" can be set to -100 cents and 100 cents respectively, and the "Dptctrl" can be assigned to another knob on a MIDI controller. This would provide a "vibrato" effect whose speed is controlled by "LFO1" (or low-frequency oscillator) and whose depth is controlled by the assigned MIDI control. Some DSP blocks take up two or three slots, and each of those slots represents a value that can be modulated using one of the assignable control sources. For instance, the "4POLE LOPASS W/ SEP" (actually two 2-pole lowpass filters which can operate in unison or at different frequencies) DSP block takes up 3 slots. The first is used to set the frequency for the filter, the second to set the resonance, and the third to set the "separation" between the two 2-pole filters. Just as in the case of the [SAW] DSP block, each of those parameters can be modulated by three control sources. A discussion of V.A.S.T. would not be complete without mentioning "FUNs". "FUN" stands for "function", and these are mathematical equations that take two values (a and b) as inputs and perform an operation on them. FUN equations include "a+b", "a*b", "b/(1-a)", and many others of varying complexity. They also allow for self-modulation; some FUNs introduce a variable "y" which represents the most recent output of the FUN. The Kurzweil evaluates each FUN every 20 milliseconds, hence it can take that value and plug it back into the equation if the equation has "y" as an input variable. Any modulation source can be assigned to a or b (or both at the same time) in a FUN. This can be used to mix two modulation sources, cause one to multiply the effects of another, and so forth. Internally, the K2000 rescales whatever value is currently being sent by the control source to a number between -1 and 1 (for bipolar control sources. Unipolar sources are scaled between 0 and 1), then applies the function and returns an output value. Using FUNS, therefore, more than three control sources can be assigned to modulate a parameter in a block since you can assign a FUN as a modulation source for "Src1", "Src2", or "Dptctl". Four