The S-direct plus gives you all the same features of the original S-direct, but in stereo. It's like having two direct boxes in one, perfect for keyboard players, or any instrument with multiple outputs. Unlike passive direct boxes, the S-direct plus is active (has a power supply), so you can rely on an even frequency response on any audio signal you connect to, regardless of its output impedance. Also, the S-direct plus' balanced outputs provide a clean signal at a low level so long runs of cable are possible. Another benefit from a balanced connection is CMR (Common Mode Rejection), which provides cancellation of interference (hums and buzzes), while leaving the original signal pure.