Radial Engineering JDI

The Radial JDI is a warm sounding passive direct box that can transfer extreme signal levels without distortion while eliminating hum and buzz caused by ground loops.

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 180º 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 plus 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 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 MuMETAL 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!

The Radial JDI... the world's finest passive direct box.

• Jensen Transformer equipped passive DI

• Eliminates hum and buzz from ground loops

• Virtually zero phase & harmonic distortion

• Exceptional signal handling and noise rejection

• Audio circuit type : Passive, transformer based

• Number of channels : Single channel (mono)

• Frequency response : 20Hz ~ 20KHz (± 0.2dB)

• Dynamic range : 135dB

• Maximum input : +21dB @ 20Hz ~ 20kHz

• Total harmonic distortion : 0.05% from 20Hz ~ 20kHz @-10dB

• Phase deviation : 0.3 @ 100Hz; 3 @ 20Hz

• Input impedance : 140k Ohms, unbalanced

• Output impedance : 150 Ohms, balanced

Features

• Transformer : Jensen JT-DBE

• Shield : Dual Faraday, MuMETAL can

• Input pad : -15dB

• Merge : Sums left & right sources to mono

• 180 polarity reverse : Inverts absolute phase

• Ground lift : Disconnects pin-1 at XLR output

• XLR configuration : AES standard (pin-2 hot)

• Speaker filter : -30dB pad and band-pass filter

• Connectors : 1/4" in & thru, XLR-M out

General

• Construction : 14 gauge steel chassis & outer shell

• Finish : Durable powder coat

• Size : (L x W x D) 5" x 3.3" x 1.8" (127mm x 84.1mm x 45.5mm)

• Weight : 1.55 lbs (703 grams)

• Shipping size : L x W x D : 6.5" x 4" x 3" (165mm x 102mm x 76mm)

• Shipping weight : 1.92 lbs (870.9 grams)

• Power : Passive, no power required

• Conditions : For use in dry locations only between 5C and 40C