I disagree. take the basic set up, constant VOLTAGE source, three pots wired across it. Whatever the slider is doing OR the input impedance of the stage its following, the controls are fully isolated.
Now replace the constant voltage with a constant current. The voltage drop across the pots is the resistance of the three in parallel times the (single) source current . Now if a pot is adjusted, the impedance of the following stage, takes more or less current. This change in current causes the voltage drop across the pots to change, which causes the voltages picked of by the other pots to change resulting in interaction between the pots. So you will need three current sources easier to use a single voltage source.
Frank