Rupert Neve RNDI-8 Digital Interphase

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 transformers, resulting in outstanding sonic performance and supremely
natural sound from 5Hz all the way out to well beyond 90kHz. Each channel can handle input levels up to
+21dBu (+31dBu 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 transformers and class-A, discrete FET
input amplifiers. 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 unamplified signal may travel 100ft or more before hitting an
amplifier.
The Class-A, Discrete FET Input Amplifiers
The class-A & discrete FET input amplifiers in the RNDI-8 are powered by 48V phantom and create a
high impedance input of over 2M Ohms, ensuring consistent performance with a wide variety of
instruments. The class-A design eliminates crossover distortion that can otherwise be added to the signal
and introduce unwanted upper-order odd harmonics. With the RNDI-8, the harmonic content is derived
from the octave (2nd order) and fifth above octave (3rd order) relative to the fundamental. 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 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 an absolutely thunderous low-end emerges, adding
an unparalleled feeling of depth. All this happens without compromising any of the midrange richness or
top-end sparkle that defines your instrument.
Maximum input level is a massive +21dBu, making the RNDI-8 capable of handling not only instruments
but also professional line-level sources like interfaces and drum machines. And with the addition of a –
10dB pad, that number soars to +31dBu – more than enough for even the highest-output DJ mixers. This
makes the RNDI-8 incredibly versatile, enhancing the sound of nearly any connected instrument or
source.
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.

FRONT PANEL

IN
Hi-Z unbalanced input. ZIN = 2.2MΩ
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 < 40Ω
PIN 1 ISOLATE
Isolates XLR Pin 1 output from circuit ground.