The Radial JDI MK3 is considered by many to be the worlds finest direct box. It is a passive DI that employs a Jensen isolation transformer for optimum audio performance offering outstanding linearity at all frequencies, combined with extraordinary level handling without introducing distortion. Being completely passive, the plug & play JDI does not require any powering and has the unique advantage of eliminating 60-cycle ground loops. This makes the JDI a definite favorite with informed audio engineers. The JDI is great for guitars, bass, and keyboards and is particularly adept with high-output, broadband instruments such as active instruments and digital keyboards. The JDI MK3 may be rack-mounted using the J-Rak and is also available in a stereo (2-channel) version called the JDI Duplex and the 6-channel rack-mountable JD6. • Equipped with Jensen transformer • Eliminates buzz and hum from ground loops • Virtually zero phase and harmonic distortion