What is a VCA?
Some expensive mixers with a large number of channels use VCA power supplies for convenience.
This section is a subset of the mixer that allows you to control multiple channels with a single power supply.
For example, suppose you have a 48-channel mixer, one part of the battery is connected to channel 3 and the other to channel 39.
Due to the large size of the mixer, you have to move a lot to check each power supply!
There are buttons next to each channel that send those channels to VCA groups and you can now control two channels with one power supply.
This function is commonly used in digital mixers such as Maidas mixers.
The number of VCA channels can be more than two. There is a point, and that is that the channel's power supply also affects the volume.
For example, if you set the channel power supply to 5dB and the other to 7dB, if the VCA power supply is fully open, it appears that those channels power supply is also on 5 and 7.
And if you turn it down, the power supply starts to decrease from one to 7 and the other to 5.
What is the use of the VCA?
VCAs are very efficient at hearing sounds. For example, 6 mixer channels can be dedicated to drums, 4 of which to vocal sound and 5 of the mixer channels to acoustic instruments.
You can separate and adjust the sounds as needed by assigning each group to a VCA controller with a power supply.
For example, just open the dedicated drum power supply and listen to the drum sound, adjust the heat and growl of the drum, and finally open the next feeders to hear the effect of the adjustment on the mix.
VCAs, however, aren't useful for sending signals to effects, and AUXs are better for that.