Hey man, I had the same issue, literally just fixed the issue. Got to use SampleOne instead as i don't think Impact has the same function. However, same process of dragging and dropping the samples into the VST. But once they are loaded up, on the bottom right hand side of SampleOne, there is a little knob under the Master knob. It will probably be on like 32 (for 32 voices), just change it to 1 and voila! I think you will need to change each sample to one shot first though.