What is gain knob for?

The gain knob is used to control the volume of a sound source. It is typically labeled with the word "Gain" or "Volume" and might also have a symbol that looks like this: ∞. The gain knob can be turned clockwise to increase the volume or counterclockwise to decrease the volume.

Some gain knobs also have a setting in the middle that is marked "Unity". This setting means that the volume is not being increased or decreased by the gain knob. Unity gain is useful for preventing distortion when combining two or more sound sources.

The gain knob is an important control for any audio system, as it allows you to adjust the volume of different sound sources to create a balanced and pleasing mix.