Radial ProD8 Passive 8 Channel DI Box 19 inch

Professional touring keyboard rigs demand uncompromising reliability, and the Radial ProD8 8-channel passive direct box sets the standard for concert-grade performance. This rack-mounted unit features fully redundant dual ¼" inputs across all channels, which are summed together to allow system technicians to patch in backup keyboards on standby should any device fail during a show. The design accommodates up to 16 keyboards or 8 stereo sets when required, whilst shared ¼" TRS effects insert jacks enable two keyboards to utilise the same effect for enhanced routing flexibility. Direct ¼" thru-put connections provide clean feeds to the artist’s playback system.

At the heart of each channel sits a custom-wound Eclipse ET-DB2 transformer that handles both impedance matching and signal balancing. With linear response from 20Hz to 20kHz, these transformers withstand the extreme dynamics typical of modern digital keyboards. Unlike active circuits that overload and produce square waves when rail voltage is exceeded, the ProD8’s transformers saturate naturally, rounding out the tone to create a warm Bessel curve characteristic of premium vintage audio equipment. The passive design provides complete galvanic isolation between source and destination, eliminating hum and buzz from ground loops for a quieter stage environment.

The output panel houses isolated XLRs, each fitted with ground lift and 180° polarity reverse switches, whilst internal switching accommodates various grounding schemes including star grounding configurations. Reversible rack ears add practical setup flexibility, allowing system techs to position inputs at the front when interfacing with external keyboards, or internally when working predominantly with rack modules. This combination of superior audio quality, extreme dynamic handling, noise elimination and versatile setup options has established the ProD8 as the world’s most popular rack DI for concert touring applications.