I'm using this for a stand alone art installation which is open for the public 24 hours a day. I want to reduce volume during the night, though, so the servo adjusts the volume based on the time. The servo is controlled by Arduino based electronics. You can find the Arduino code here: https://github.com/royrobotiks/Time-based-volume-control
Technical
Mackie 402VLZ4
Tower Pro SG90 micro servo
3 long zip ties