Rupert Neve Designs RNDI Active Transformer Direct Interface

Stunning tone & clarity for all of your instruments.
The RNDI contains a custom Rupert Neve-designed output transformer and class-A, discrete FET input stage. This carefully designed combination is the key to the RNDI's unparalleled performance, delivering a powerful and vibrant direct sound that captures the full harmonic depth of basses, guitars, acoustic instruments, and even pre-recorded material.

With portable, powerful, larger-than-life tone for a variety of instrument and amplifier signals, the RNDI is truly the first stand-alone DI worthy of the Rupert Neve name.

The Development
After coming into existence during an experimentation with new transformer designs, the RNDI was fine-tuned over a series of listening tests against the most popular high-end DIs available. It was in these tests where the RNDI always seemed to add another dimension to the sound and bring the instruments to life. The lows felt richer, deeper and fuller, and the highs had outstanding clarity without any added harshness.

Signature Sound
The RNDI's signature sound is the result of a new Rupert Neve-designed output transformer and a class-A, discrete FET input stage. The carefully orchestrated union of these two elements is key to the RNDI's accuracy, tone and response.

The Transformer
The custom output transformer provides exceptional isolation while introducing musical harmonics and dimension to the sound. The low impedance, transformer-balanced output excels at driving long cable runs, and performance is immensely consistent regardless of the connected equipment. This is very important for both live and studio environments where the audio signal may travel over 100ft before hitting an amplifier.

The Class-A, Discrete FET Input Stage
The class-A, discrete FET input stage in the RNDI is powered by 48V phantom, providing a high impedance input of 2.2M Ohms that ensures consistent performance with a wide variety of instruments. The class-A design introduces no crossover distortion to the signal, which can add upper-order odd harmonics that are musically dissonant in nature. With the RNDI, the majority of harmonic content is a pleasing combination of 2nd order (octave) and 3rd order (fifth above octave). These musically relevant harmonics, present in subtle amounts, enhance the richness of the original signal and provide a distinctly musical response. And the discrete nature of the RNDI design means there are no ICs or digital components that can have negative effects on the tone.

Massive Headroom + Speaker Mode
In Instrument Mode, the RNDI's uniquely high input headroom of +20.5 dBu is capable of handling not only instruments, but a wide variety of sources, such as synths, keyboards, drum machines and even pre-recorded material. This allows the RNDI-M to inject that coveted Rupert Neve Designs tone into a wide variety of sources.

In speaker mode, the RNDI can handle the screaming output of a 1000-watt solid-state power amplifier (92 Vrms or 266Vp-p) to capture the full tone of the instrument, preamplifier, EQ, inserts, and the amplifier's output stages before it hits the speaker cabinet. This technique allows the engineer to avoid any bleed in a live environment and any unwanted tone added by the speaker cabinet or microphone. Also, speaker mode can be especially useful when feeding the RNDI line-level sources since it increases the input headroom even further...

When used with modern amp / speaker emulation plug-ins or hardware (like a Kemper or Fractal unit), this technique allows the engineer to take advantage of both the flexibility of digital modeling and the superior non-linear response of an actual analog amplifier.

Features

Groundbreaking Direct Tone
When class-A, discrete amplifiers meet Rupert's custom transformers, good things happen to your tone. The RNDI is imbued with the unique components and design knowledge that makes it worthy of the Rupert Neve name.

Huge Headroom
The high input headroom of +20.5 dBu (typical) is capable of handling a wide range of sources - and in speaker mode, the RNDI can handle the full output of a 1000-watt power amplifier (92 Vrms or 266Vp-p).

Rugged Solid Steel Frame
The rugged steel chassis features an industrial-grade powder coating, and is built to withstand the severe stresses of life on the road.

Use a Variety of Sources
The RNDI has immensely consistent performance across a wide variety of sources due to its 2.2M Ohm discrete FET input stage and high headroom. The RNDI can be used with confidence on guitars, synths, basses, acoustic instruments, keyboards & drum machines. And in speaker mode the input headroom increases even further, providing an easy way to inject the pleasing harmonic content of the RNDI into literally any source.

Drive Longer Lines
The low impedance transformer-coupled output - below 40 ohms - is capable of driving long lines while maintaining exceptional high frequency performance.

1/4" THRU Output
In instrument mode the THRU output can feed the amplifier input for reinforcement. In speaker mode, the THRU is used to feed the amplified signal to the speaker.

Ground Lift
A ground lift switch is provided on the back to help fix any problematic grounding.

Phantom Powered
The RNDI is powered by standard 48V phantom power. Power is indicated by a blue LED on the front panel.

Controls & I/O

1/4" Input
Hi-Z unbalanced input:
• 2.2M Ohms (Instrument)
• 200 kOhms (Speaker)

1/4" THRU
Parallel 1/4" port used to send signal to an amp (instrument mode) or speaker (speaker mode).

Speaker / Instrument Input Level
• Selects Speaker or Instrument level
• Max input: +20.5dBu Instrument, +41dBu Speaker

48V Power LED
Indicates that +48V phantom power is present from the connected mic preamp (required to power the RNDI).

Ground Lift
Isolates the XLR Pin 1 from the circuit ground.

Output
Transformer-balanced XLR output. Impedance less than 40 Ohms. Phantom power to the RNDI is supplied through this connection.