So one wouldn't need a mixer at all...just plug the mic into the Voice Live Touch and then the latter into the line in on the keyboard (Tyros4 or microArranger). In the case of the microArranger, the on-board speakers could/would be used (at smaller more intimate gig settings, of course).
Hi Ian, after more thought, I agree that bringing in the mic signal (post Voice Live Touch) into the keyboard via the MicroArranger's line-in jack should probably work, including the ability to adjust the mic volume, not from the MicroArranger, but on the VLTouch, but only by going out of the VLTouch via it's 1/8" stereo headphone output jack & using its accompanying output vol control knob, because the VLTouch's XLR & TRS outputs don't include output vol signal control. The MicroArranger's input jack is merely MONO, so I assume that a 1/8" stereo to 1/4" mono converter cable will be required as well for this setup. The only 'very minor' drawback to this method is that any 'stereo' vocal effects applied by the VLTouch will be heard mono thru the MicroArranger's built in Speakers and the keyboard's output - Scott