As Totty says "In Logic X I get regular but intermittent clicks upon playback and
programming. This type of click I am 80-90% sure is an interruption
TI/VC communication over USB. The core result of this audible click is a
"wobble" of pitch (as if the tempo/timing info is being resynchronised)
along with any delay line present exacerbating the problem."
I get the warbled pitch thing going on and USB Driver being kicked out, so have to restart Logic and the Ti