USB audio recording using TC helicon voic live GTX

Hi all
I am using I pad 2 16 GB with cubasis, I plug my I pad using camera kit (Not apple) into voice live GTX using USB.
every thing work well, but when I want the record only voice into the audio channel it is not possible.
i want to record singing channel when i hearing the playback is it possible ?
Please help

i think it’s a TC Helicon issue - i wasn’t able to separate vocals from gtr over USB, no matter what the “Output” setting was.