Rupert Neve Designs RNDI-S Stereo Active Transformer Direct Box

Unmatched Harmonic Depth for Every Stereo Source

The Rupert Neve Designs RNDI-S is a two-channel active transformer direct interface engineered to provide your instruments with massive tone and unparalleled headroom. Built for mixing engineers, synth enthusiasts, and touring musicians, this stereo DI captures the full harmonic depth of basses, guitars, keyboards, and consumer devices. Whether in the studio or on the road, the RNDI-S ensures your mono and stereo sources deliver a "record-ready" sound from the very first note.

Signature Neve Transformer Warmth
At the heart of the RNDI-S are two custom Rupert Neve-designed output transformers that introduce musical harmonics and dimension while providing exceptional passive isolation. These transformers allow you to drive long cable runs—often exceeding 30 metres—with minimal signal loss or high-frequency degradation, ensuring consistent performance in both live and studio environments.

Discrete Class-A FET Precision
The active circuitry features a discrete, Class-A FET input stage powered by standard 48V phantom power. This high-impedance design (2.2M Ohms) prevents loading on passive pickups, delivering a transparent signal free from the crossover distortion commonly found in integrated circuits or digital components. The result is a bold, vibrant tone with rich low-end and sweet highs.

Versatile Connectivity for Modern Workflows
Specifically designed to accommodate the needs of modern performers, the RNDI-S includes a dedicated 3.5mm stereo input for seamless integration with mobile devices, laptops, and tablets. Encased in a rugged steel "clamshell" chassis, this unit provides the professional durability required for life on tour while maintaining the sonic excellence expected of the Neve name.

Main features:

• Custom Rupert Neve Designs transformers for rich, powerful tone
• Discrete Class-A FET amplifiers ensure unrivalled clarity
• Exceptional performance across any instrument or line-level source
• Low-impedance output drives long lines with minimal signal loss
• Formed steel chassis built to withstand the rigours of the road
• Independent 48V phantom power required for each channel
• Excellent phase coherence across the entire frequency spectrum
• Dual ground lift switches to eliminate hum and ground loops

Tech Specs:

• Type: 2-Channel Direct Interface (DI Box)
• Frequency Response (+/- 0.25 dB): 28 Hz – 60 kHz
• Frequency Response (+/- 1 dB): 14 Hz – 90 kHz
• Noise (22 Hz - 22 kHz, Un-weighted): Better than -110 dBV
• THD + Noise (1 kHz, +20 dBu Input): 0.25% Typical (2nd and 3rd Harmonic)
• THD + Noise (1 kHz, -20 dBu Input): 0.015% Typical (2nd and 3rd Harmonic)
• Input Impedance (Instrument): 2.2 Megohm
• Input Impedance (3.5mm): 95 Kilohm
• Output Impedance: Less than 40 Ohm
• Max Input Level (Instrument): +20.5 dBu (8.2 Volts RMS)
• Max Output Level: +11.5 dBu Typical
• Power: 4.5mA per channel @ +48VDC
• Dimensions (WxDxH): 12.7 x 17.8 x 4.5 cm
• Weight: 1.1 kg
• Explore Rupert Neve Designs: https://rupertneve.com/products/rndi-s