The VCA fader in Samplitude Pro X2, whose usability and comfort is based on large analog mixing consoles, is natively integrated in the DAW. The VCA fader allows you to control all relevant levels when mixing your project. Each existing channel strip can be easily turned into a VCA fader. You can also assign individual channels to a VCA group and control them using the VCA fader in the mixer. You can assign as many channel strips as you want to a VCA master fader. By displaying “Ghost faders”, the resulting change can also be read out in the individual channels depending on the VCA master.

Here is more about this on Wiki
http://en.wikipedia.org/wiki/Variable-gain_amplifier

[GALLERY=media, 351]Dave Rat - Live Sound Mixing Strategy - YouTube by audiokid posted Mar 26, 2015 at 5:27 PM[/GALLERY]