For reference: http://forum.eventide.com/cs/forums/p/8043/36179.aspx#36179

"Hi,

At this time, you can't control the input gain on the TimeFactor. Although this is unsupported, my suggestion would be to get a splitter/mixer or true bypass loop, and then put a volume pedal in front of the TimeFactor but after your signal has [been] split. "

Thanks,

Nikhil