The Calibration Dial increases the sensitivity of the NERVANA Generator to softer or quieter music. Because the signal is somewhat volume dependent in Audio Mode / Line In, you may need to increase the Calibration Dial clockwise in order to see the signal chevrons (“>> >> >> …”) moving across the screen from left to right. The NERVANA Signal best follows music when the chevrons move as far to the right as possible without continuously staying at the right side.
So, if you can do so comfortably, try turning the music volume up a level or two when you are first using NERVANA. If you are listening to music that is soft or quiet, turning the Calibration Dial up (clockwise) will increase the occurrence of the signal – it will not affect the volume of the music from the earbud speakers. Volume is completely controlled by your music source.