What is the difference between AGC (Automatic Gain Control) and ALC (Automatic Level Control) ?

What is the difference between AGC (Automatic Gain Control) and ALC (Automatic Level Control) ?

AGC keeps an input signal at a target gain level that you select, and is generally used for Line Input channels. ALC automatically keeps an input signal at a constant level, and is generally used to keep speech levels constant on Mic Input channels.