Rupert Neve Designs RNDI-8 8-Channel 1U Active Transformer Direct Interface

Legendary tone, unquestionable reliability. Eight channels of the superb-sounding RNDI in one rack space.
With over 25,000 channels shipped since its launch in 2015, the RNDI is firmly established as the direct interface of choice for many of the world's most discerning musicians and engineers. Its custom transformers and discrete FET input stages deliver a vibrancy and clarity that captures the full harmonic depth of any source, and its unquestionable reliability has led to its adoption by thousands of touring artists.

The RNDI-8 puts eight channels of this beloved circuit into a single rack space, making it the ideal solution for high-end stage rigs, studios, and synth enthusiasts. With the RNDI-8, stunning direct sound doesn't require extra work - it's just there.

The RNDI-8 consists of eight independent channels of RNDI Active Transformer Direct Interface in a single rack space, providing instrument direct injection for electric guitar & bass, synthesizer, keyboard, piezo pickup, or any other instrument-level source.

The discrete, class-A circuit topology is built around Mr. Rupert Neve's custom output transformers, resulting in outstanding sonic performance and supremely natural sound from below 5Hz all the way up to well beyond 90kHz. Each channel can handle typical input levels up to +20.5 dBu (+30.5 dBu with the pad engaged), the low impedance transformer-coupled output drives long lines with minimal loss, and the rugged chassis' steel construction is designed for a lifetime of stage and studio use.

Transformer + Discrete FET: The Best of Both Worlds
The RNDI-8's signature sound stems from the custom-designed output transformers and the class-A, discrete FET input stages. The carefully designed union of these two elements is key to the RNDI-8's unique accuracy, tone, and response.

The Eight Custom Transformers
The RNDI-8's custom-wound output transformers provide isolation while adding musical harmonics and dimension to the sound. The low impedance, transformer-balanced outputs excel at driving long cable runs, and the performance is consistent regardless of the connected equipment. This is important for both live and studio environments where the audio signal may travel 100ft or more before hitting an amplifier.

The Class-A, Discrete FET Input Amplifiers
The class-A & discrete FET input stages in the RNDI-8 are powered by 48V phantom and create a high impedance input of 2.2M Ohms, ensuring 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-8, 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. Furthermore, the discrete aspect of the RNDI-8's design means there are no ICs or digital components to potentially cause negative effects on the tone.

Giant Headroom, Wide Bandwidth
The RNDI-8 has a uniquely wide bandwidth with a frequency response stretching from below 5Hz all the way past 90kHz. However, measurements are only part of the equation: couple this extended bandwidth with the output transformer's harmonic enhancement and a thunderous low-end emerges, adding an unparalleled feeling of depth. All this happens without compromising any of the midrange richness or top-end sparkle of the source.

The RNDI's uniquely high input headroom of +20.5 dBu is capable of handling not only instruments, but sources such as synths, keyboards, drum machines and even pre-recorded material. And with the addition of a -10dB pad, that number soars to +30.5dBu - allowing the RNDI-8 to inject that coveted Rupert Neve Designs tone into a wide variety of sources.

Two Distinct Ground Lift Options
Most direct interfaces include a ground lift switch at the output, and the RNDI-8 includes this standard DI 'lifting' option via eight individual 'Pin 1 Isolate' switches on the rear panel. Engaging this button will usually eliminate common sources of hum in the signal path.

However, the RNDI-8 also includes eight ground lift buttons on the front panel which separate each channel's circuit ground from the chassis ground, providing another helpful option to detect and eliminate unwanted ground hum.

Features

Groundbreaking Direct Tone
When class-A, discrete input stages meet Rupert's custom output transformers, magic happens. The RNDI-8 contains the unique components and design knowledge that make it worthy of the Rupert Neve name.

Huge Headroom
Capable of handling not only instruments, but sources such as synths, keyboards, drum machines and even pre-recorded material. And with the addition of a -10dB pad, the input headroom soars to +30.5dBu - allowing the RNDI-8 to inject that coveted Rupert Neve Designs tone into a wide variety of sources.

Rugged Solid Steel Frame
The rugged steel 1U chassis features an industrial-grade powder coating and is built to withstand the severe stresses of life on the road. The included bolt-on rack ears are reversible for multiple mounting options.

Use With a Variety of Sources
The RNDI-8 has immensely consistent performance across a wide variety of sources due to its 2.2M Ohm discrete FET input stages and high headroom. The RNDI-8 can be used with confidence on guitars, synths, basses, acoustic instruments, keyboards & drum machines. And with the -10dB PAD 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 outputs - below 40 ohms - are capable of driving long lines while maintaining exceptional high frequency performance.

1/4'' THRU Outputs
The THRU outputs can be used to feed amplifier inputs for reinforcement.

Ground Lift Options
Pin 1 Isolate switches are provided on the rear panel to help fix any problematic grounding, as well as Ground Lift switches on the front panel to isolate each channel's circuit ground from chassis ground.

Phantom Powered
Each of the RNDI-8's eight channels is powered by standard 48V phantom power. Power is indicated by blue LEDs on the front panel, one per channel.

Front Panel

IN
Hi-Z unbalanced input. ZIN = 2.2M Ohm

THRU
Parallel 1/4" jack that allows the user to pass the input signal directly to an amplifier.

48V
Indicates when +48VDC phantom power is active on the channel.

GND Lift
Isolates each channel ground from the chassis ground.

-10dB PAD
Attenuates the input signal by -10dB (1/4" THRU unaffected).

Rear Panel

Output
XLR DI output utilizing custom Rupert Neve Designs transformer. ZOUT < 40 Ohm

Pin 1 Isolate
Isolates XLR Pin 1 output from circuit ground.