AnalogX Vocal Remover works on the same principles that the hardware removers do - that in most instances vocals are equally mixed in both channels, and can identified removed by simply changing the phase on one channel by 180 degrees. While this won't remove vocals in all instances, it does work in many cases, and can sometimes be used to remove bass or breakbeat sections as well, which I find to be GREAT for sampling! Depending on the effects used on the vocals, sometimes the reverb or ambience of the vocals is left.