Radial Engineering JDI Duplex Dual Channel Passive Direct Box with Jensen Transformer Isolation and Ground Lift Control

The Radial Engineering JDI Duplex is a premium dual-channel passive direct box designed for professional audio conversion of stereo or two independent mono sources. Built around high-performance Jensen transformers, it delivers exceptional clarity, ultra-low distortion, and accurate signal translation for live sound, studio recording, and broadcast applications.

Engineered for maximum flexibility, the JDI Duplex supports a wide range of input types including 1/4” instrument inputs, RCA, 3.5mm stereo, and XLR connections, making it ideal for keyboards, playback devices, laptops, media players, and other line-level audio sources. Each channel operates independently, allowing precise routing and consistent stereo imaging or dual-mono distribution.

The premium Jensen transformers provide superior isolation, eliminating ground loops, hum, and noise while preserving the natural tone and dynamics of the original signal. A built-in ground lift switch further enhances noise control in complex system setups. As a fully passive device, the JDI Duplex requires no external power, ensuring dependable performance in any environment.

Housed in a rugged 14-gauge steel chassis, the unit is engineered for touring durability while maintaining Radial’s industry-leading audio transparency.

Key Features:

• Dual-channel passive direct box for stereo or dual mono sources
• Premium Jensen transformers for ultra-clean signal conversion
• Multiple input options: 1/4”, RCA, 3.5mm, and XLR
• Ideal for keyboards, playback devices, laptops, and media sources
• Ultra-low distortion with wide frequency response
• Transformer isolation eliminates hum and ground loops
• Ground lift switch for improved noise control
• Passive design—no power required
• Rugged steel chassis for touring and studio reliability