I’m a longstanding advocate of VCA tracks in Pro Tools. No longer a feature restricted to HD/Ultimate users, this track type can be unfamiliar to some users, particularly those who have come to audio from traditional analogue workflows. These tracks are best described as master faders for Mix Groups and as such they offer some overlap with traditional subgroups with can be achieved using Auxiliary tracks.
How Can I Use VCAs When Tracking?
VCAs can of course be used to control the monitoring level of a group of tracks but the record and input monitor buttons if you click on them are little more are status indicators. They light up when one or more of the members of their group is record enabled but if you click on them nothing happens.
To toggle the record enable status of a VCA’s grouped tracks imply Alt/Option + Click on it. This also applies to Input Monitor.