Radial JDI Duplex Top View
Radial JDI Duplex Panels
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  • Tom Coster and the Radial JDI Duplex
    Tom Coster

    "The Radial Duplex is musical and transparent and is with me everywhere that I go. Thanks Radial for a superior product."

    Tom Coster
    (Santana, Billy Cobham, Larry Coryell)
    Tom Coster
  • Tony Levin and the Radial JDI Duplex
    Tony Levin

    "I have found that with the Radial JDI direct box, my bass comes through extremely clean, very quiet, and with a smooth transparent low end. I use my Radial DI for everything."

    Tony Levin
    (Peter Gabriel, King Crimson, John Lennon)
    Tony Levin
  • Robert Scovill and the Radial JDI Duplex
    Robert Scovill

    "The Radial products are the most transparent, technically comprehensive devices I have ever run across. They are right at the top of my list of 'gotta haves'."

    Robert Scovill
    (Tom Petty, Matchbox Twenty, Rush)
    Robert Scovill
Radial JDI Duplex

JDI Duplex™ Stereo Direct Box

Part No. R800 1020

  • Stereo direct box for high output sources
  • Ultra linear response from 10Hz to 40kHz
  • Virtually zero phase & harmonic distortion
  • Eliminates hum and buzz from ground loops

The Radial JDI Duplex is a full-feature, stereo passive direct box designed to enhance connectivity, reduce noise, and simplify the hectic life of the touring professional, broadcast engineer or AV integrator. It is plug-and-play easy to use while delivering the utmost sonic quality.

Like the Radial JDI, the Duplex employs two high-performance Jensen audio transformers with the same pristine audio signal path that has made the JDI the industry standard. It features exceptional signal handling with virtually zero phase shift or harmonic distortion, while remaining linear across the entire audio spectrum. When driven to extremes, the natural transformer saturation and resulting warm Bessel curve makes the Radial Duplex the perfect choice for smoothing out highly dynamic instruments such as digital pianos and electronic drums that can sound harsh when pushed. Transformer isolation provides the additional benefit of eliminating troublesome ground loops that can cause hum and buzz in the audio system or interfere with video displays.

This 'Swiss Army knife' DI is equipped with ¼' connectors for instruments, RCA connectors and a 3.5mm TRS for unbalanced -10dB consumer electronics plus XLR inputs for +4dB professional line sources. Radial's innovative book-end design provides protective zones on the front and rear to keep connectors and switches out of harm's way. The 14 gauge I-beam inner frame adds tremendous rigidity to eliminate outside stresses that could torque the PC board and cause premature solder joint and trace failure. The steel outer shell couples with the transformer's MuMETAL® shield to protect against stray magnetic fields from power transformers or lighting systems that could cause interference. Finally, a full-bottom no-slip pad works double-duty by providing both mechanical and electrical isolation. The Radial Duplex delivers outstanding connectivity, superlative audio and quiet dependable performance..

JDI Duplex… the world's finest passive stereo direct box.


Passive Direct Box


Rackmount Direct Box


Specialty Rackmount & Desktop Adaptors

JDI Duplex™ - Applications
Using the JDI Duplex with a Stereo Keyboard
Duplex with Stereo Keyboard

The Duplex is able to withstand huge transients without distortion. This gives digital keyboards a warm, smooth vintage tone.

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Using the JDI Duplex with Two Stereo Sources
Duplex with Two Stereo Sources

With the dual stereo architecture, the Duplex can easily be set up to handle two different stereo sources at the same time.

Using the JDI Duplex in Multimedia Systems
Duplex in Multimedia System

Whether you have a CD player, iPod, computer or professional +4dB balanced source, the Duplex can handle any situation.