kontroller S3 MK3 with low headphone volume and low master volume

Stefano1604

Good evening, after a month I turn on my S3 MK3 and the master volume doesn't feel as loud as before and the headphone output feels low. To reach a high level I have to use the gain knob before I almost never touched it. The power supply output measures 12V. How much is the console powered at 12 volts or 15 volts, who can help me? Thank you Stefano