Yes, if you want to be able to control the air pressure.
A double action-airbrush is not designed to control the amount of air, it is designed to control the amount of paint only. It is called a double-action because the air on or off and paint flow are both controlled by the trigger.
Mike
“Wisdom is the right use of knowledge. To know is not
to be wise. Many men know a great deal, and are all the greater fools
for it. There is no fool so great a fool as a knowing fool. But to know
how to use knowledge is to have wisdom. " Charles Spurgeon