Unigain 64
It would be hard to make a simpler plugin : only one controller for 1 to 64 channels levels !
But it can be very useful to play and automate a multichannel object’s volume in Reaper with a MIDI controller, or just as an intermediate gain adjustement between some plugins.
If you need to change the level of individual channels see the MultiLevels.
Visit: Unigain 64