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!
Jensen Transformer equipped passive DI
Eliminates hum and buzz from ground loops
Virtually zero phase & harmonic distortion
Exceptional signal handling and noise rejection
Typical DI stage/studio setup: The JDI is used primarily to get an instrument signal to a mixing desk or PA system without coloring the natural sound in any way.
JDI with acoustic guitar: Here the JDI is used to provide the front-of-house PA system with an balanced unaltered clean guitar signal for final EQ and effects processing.
JDI with a stereo keyboard: With keyboards or other stereo instruments, the JDI's 'merge' function can be employed by sending one channel to to the 'thru' jack. With the 'merge' switch engaged, the two channels are summed to mono and sent to the XLR output.
Passive transformer isolated
10Hz ~ 40kHz
Signal to noise
0.1dB - 20Hz to 20kHz
Maximum input level
4º at 20Hz, 0º at 1kHz
.006% @ 20kHz
: 100dB @ 60Hz
¼" jack for INPUT - ¼" jack for THRU
MERGE MIX function
Stereo to mono merge switch (usig IN and THRU jacks)
-15dB pad on input
AES standard… pin-1 ground, pin-2 hot
LIFT switch - XLR outs pin-1
14 gauge steel chassis and outer shell, baked enamel finish