Im sure a lot of you guys have seen this sweep effect, I used to use it on my old controllers when I was using traktor 1. Recently I've been trying to map it for Traktor 2 on my S4, but have ran into a problem immediately on the first control in the video.

It says to map a knob as a button to choose iceverb right when the knob moves. This was possible in Traktor 1, but I have found that Traktor 2 does not let you map a knob as a button. Does anyone know of a workaround or possibly another sweep effect that has been used in Traktor 2?