i finally got a new keyboard controller that has aftertouch, so now i'm enjoying adding vibrato at the press of a key. now i'm wondering what the "length" knob does on the kontakt player. I remember reading that it controls the speed of the vibrato, but maybe i'm remembering incorrectly, and i'ts not working for me anyway. the length knob does nothing for me as far as i can tell. will someone please tell me what this function does and how to use it?