The Stax Basic System is a complete electrostatic earspeaker system. Comprised of both the Basic earspeaker unit (SR-202) and their most basic driver unit (SRM-252) the system is fed by a 12VDC power supply and requires a source with stereo RCA outputs. On this most recent revision Stax has included a loop-out on the RCA inputs, allowing for daisy chaining of other audio components. Designed and distributed primarily in Japan, two versions are sold: The SRS-2050A, which includes a Japanese 100V power supply, and the SRS-2050II, which includes a power supply compatible with the voltage of the mains in the country of sale.