Accu Box S2 is a clean accu power supply and has an incredible synergy with all Phono Boxes. Using Accu Box S2 on any of our recommended products, results in a more homogeneous and spacious sound with better separation and imaging. The sound will come across as more cleaned up overall, giving you a relaxed listening experience with mind numbing sonics. Accu Box S2 uses five cells or rechargeable Li-Pol batteries with a capacity of 2.6Ah. For protection of the batteries Accu Box S2 comes with over-charge, over-discharge and over-current protections, to ensure the maximum life-span of our product. Furthermore Accu Box S2 also offers a 5V USB A output, for other products, such as DACs.