Radial Engineering JDI Duplex – Dual-Channel Premium Passive DI with Jensen Transformers

The Radial Engineering JDI Duplex is a premium two-channel passive direct box designed for pristine signal integrity in demanding professional environments. Equipped with dual Jensen nickel-core transformers, the JDI Duplex delivers unmatched clarity, phase accuracy, and noise isolation—ideal for keyboards, acoustic instruments, bass, synthesizers, and stereo playback devices. Built with Radial’s legendary tank-like construction, it is a long-term investment for studios, touring rigs, and broadcast facilities.

Key Features

• Dual Jensen transformers: Provide ultra-linear frequency response with minimal phase distortion and zero saturation.
• True passive isolation: Eliminates hum, buzz, and ground-loop noise across both channels.
• Two-channel stereo design: Perfect for keyboards, stereo instruments, or dual mono sources.
• Pad & Sum switches: -15 dB pads handle high-output instruments; Sum Mono combines stereo sources when needed.
• Rugged steel chassis: 14-gauge welded I-beam construction with bookend design protects switches and connectors.

Customer Benefits

The JDI Duplex preserves the pure tone of your instruments with exceptional detail and dynamic accuracy. Its dual-channel design replaces two separate DI boxes, simplifying setup while delivering world-class audio quality for stereo rigs and multi-instrument performers.

Quick Specs

• Type: Two-channel passive DI
• Transformers: Jensen nickel-laminated core
• Frequency Response: 10 Hz – 40 kHz (flat)
• Pads: -15 dB on each channel
• Inputs: 2 × 1/4" Hi-Z + 2 × thru jacks
• Outputs: 2 × balanced XLR (lo-Z)
• Sum Mono: Converts thru to dual-input mono mode
• Construction: 14-gauge steel, bookend protective design

What’s in the Box

• Radial Engineering JDI Duplex
• User documentation

Use Cases / Ideal For

Stereo keyboards, digital pianos, synthesizers, acoustic instruments, bass guitars, playback devices, studio tracking, broadcast rigs, and touring FOH setups.

Compatibility

Works with any mixer, stage box, or audio interface. Perfect for long cable runs and high-output instruments without distortion or noise.

Pros & Cons

✅ Pros:

• Industry-leading clarity thanks to Jensen transformers
• Stereo/dual-mono flexibility
• Extremely rugged touring-grade build
• Zero-power passive operation

⚠️ Cons:

• More expensive than basic DI boxes
• Passive design may be less optimal for very low-output pickups

The Radial JDI Duplex delivers unmatched fidelity, isolation, and reliability for stereo and dual-channel DI applications.