The DAC units have the ability to adjust the maximum and minimum volume settings. When the DAC-2 is being used in your system the sound might not become audible until a setting well above 0. If your system produces no sound until a value of 15 is reached you can set the volume floor accordingly so that the unit starts at 15 eliminating the soundless gap. The unit is pre-set with a floor of 23 because most systems will not produce sound until somewhere around that value. The Max setting of the DAC-1 and DAC-2 can be limited to prevent over powering your system and damaging your components as well as provide optimal output so your pre-amp operates in a favorable range. The settings can be customized for each output independently. If you refer to the section entitled Volume Min/ Max Settings of the DAC-2 manual it will explain this feature in detail. The section entitled Max Volume Settings in the DAC-1 manual will explain the features function. The section titled Setup Menu in the manuals will explain how to activate the setup mode of the DAC units and show you a layout of the programming table so that you can customize their features.