The ULTRA-DI PRO DI800 is a professional mains/phantom powered 8-channel active DI-box. If you need a rack-mountable DI unit with enough inputs to accommodate everyone on stage or in the studio. Direct Injection (DI) boxes make it possible to connect guitars, basses and keyboards (as well as other line-level devices) to audio mixers and recorders. They are absolutely essential for proper impedance-matching and to maintain signal integrity. Our active DI800 features “buffered” inputs that respect your source signal much better than passive DI boxes. Balanced signals leaving the DI800 are extremely low-impedance (typically less than 680 Ohm), and far less susceptible to noise and RF Interference (RFI).