| The Radial JDI is a passive direct box designed to handle extreme signal levels without distortion of any kind. Unlike an active DI that is limited by the buffering amplifier’s rail voltage, the JDI employs a Jensen audio transformer as the engine. Jensen transformers are legendary in their ability to gracefully handle transients while delivering a smooth, warm sounding Bessel curve, reminiscent of the finest vintage gear. Ruler flat from 10Hz to 40kHz and with virtually zero phase deviation, the JDI delivers the natural, pure sound of the instrument without artifact.
The 100% passive circuitry inside the JDI is incredibly efficient. The transformer performs both high-to-low impedance conversion and signal balancing at the same time with minimal loading and does so without any power whatsoever. The transformer also introduces a magnetic bridge that passes signal while rejecting stray DC voltage. This makes the JDI particularly adept at eliminating hum and buzz caused by ground loops.
Features include input and throughput ¼” connectors, -15dB input pad, ground lift, and 180 degree polarity reverse to help phase align the instrument with the PA. A secondary circuit is added for direct interfacing with high output devices such as guitar or bass amp loudspeakers. And a unique merge function allows stereo sources such as keyboards to be summed mono, saving valuable input channels.
Built tough to handle the abuse of live touring, the JDI features a 14 gauge welded steel I-beam inner frame and a unique book-end outer shell. The innovative design eliminates stress on the PCB, reducing opportunity for solder joints to go ‘cold’ while the outer shell creates a protective zone around the switches and connectors. The steel casing resists noise-causing electromagnetic pollution and the transformer’s sensitive inner workings are further protected from magnetic fields with a mu-metal can. This ensures the signal transfer is quiet and free from hum.
These combined features have made the Radial JDI the most popular passive direct box in professional touring and an excellent choice for instrument interface in the studio.
 Using
the JDI
The JDI is plug-and-play easy to use. Connect the source
to the JDI 'INPUT' connector. Use the 'THRU' connector to
connect to your personal monitoring system and connect the
XLR output to a mic level input of a mixer or sound system.
If the level is hot, like from a synth, keyboard, or drum
machine, depress the -15dB pad. If you encounter any buzz
or hum, depress the ground lift switch to lift the ground
at XLR pin-1. Use the 180° Polarity switch to correct
the signal phase if needed.
For complete details, please read the JDI
owner’s manual. This covers important safety rules
that can be applied to all system setups and discusses all
of the features in more detail.
| WARNING
- Possibility of electrical
shock hazard exists. Please read the warnings in the user
manual before attempting to connect amplifiers to
this device. |
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