RNDI-S
Stereo Active Transformer Direct Interface
OVERVIEW / MEDIA / FEATURES / REVIEWS / SPECS & RESOURCES
An expanded two-channel version of our best-selling RNDI, providing massive tone & headroom for all of your instruments & stereo sources.
The RNDI-S signature sound is the product of custom Rupert Neve Designs transformers and class-A biased, discrete FET amplifiers. The carefully orchestrated union of these two elements is key to the unique response of the RNDI-S, delivering a powerful and vibrant direct sound capable of reproducing the full harmonic depth of basses, guitars, keyboards, acoustic instruments, professional line-level sources and consumer devices with a 3.5mm jack.
With portable, powerful, larger-than-life tone, the RNDI-S is ready to make your stereo or mono direct sources shine.
“Wow. So THAT is what my Nord is supposed to sound like. Game changer.”
The Development of the RNDI
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.
Most importantly, the design team noted:
“As musicians, the RNDI consistently stood out as the DI we wanted to play through.”
Active + Passive: The Best of Both Worlds
The RNDI-S and RNDI’s signature sound is the product both of new custom Rupert Neve-designed transformers and class-A biased, discrete FET amplifiers. The carefully orchestrated union of these two elements is key to their unique response.
THE TRANSFORMERS
The custom transformers provide superior passive isolation while adding 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 unamplified signal may travel almost 100ft before hitting an amplifier. In other designs, these high-capacitance lines cause major reductions in high frequencies – not so with the RNDI.
THE CLASS-A, DISCRETE FET AMPLIFIERS
The class-A & discrete FET amplifier in the RNDI is powered by 48V phantom, and creates a very high impedance input of 2M Ohms that ensures consistent performance with a wide variety of instruments. The class-A design ensures that zero crossover distortion is added to the signal, which can add upper-order odd harmonics that are musically dissonant in nature. With the RNDI, the overwhelming majority of harmonic content is 2nd order (octave) with some 3rd order present (fifth above octave). These musically relevant harmonics, present in subtle amounts, actually add to the richness of the original signal. And the discrete aspect of the RNDI design means there are no ICs or digital components that can have negative effects on the tone.
CONTROLS & I/O
2x ¼” INPUTS
Hi-Z unbalanced inputs with 2.2M Ohms input impedance.
2x ¼” THRU JACKS
Parallel ¼” jacks used to send signal to an amp or speaker.
3.5MM INPUT
Stereo unbalanced input with 95 kOhm input impedance. Ch 1 = Tip, Ch 2 = Ring.
INPUT SELECT
Selects ¼” Input or 3.5mm Input.
48V POWER LEDS
Indicates that +48V phantom power is present for each channel from the connected mic preamp(s). Power must be supplied independently to both channels.
GROUND LIFTS
Isolates the XLR Pin 1 from the instrument input ground.
OUTPUT
Transformer-balanced XLR output. Impedance <40 Ohms. Phantom power to the RNDI-S is supplied through these connections.
FEATURES
Custom Rupert Neve Designs transformers for rich, powerful tone
Exceptional performance with any instrument
Unrivaled clarity from discrete FET amplifiers
Drives long lines with minimal loss
Rugged steel frame built for life on the road
Powered by dual 48V phantom power
Excellent phase coherence at all frequencies
REVIEWS
“I mix FOH for a prominent country artist. We tour and play over 200 shows a year and we go through a lot of gear. I ran into someone who was using this for his bass DI line and I heard him do a comparison. I was sold instantly. So I finally bought one to use for an acoustic line in between the output of a Shure UR4D and the input of a Midas DL431. It literally took the tone and changed it immensely. Sounded like I had plugged it into a console in a studio. So I started progressively changing every DI on stage over to RNDI's. Today, I use 7 channels of RNDI for all my direct signals on stage. I haven't changed them all over just yet, but I swear I'm getting there. Eventually every DI line on deck will be RNDIs and I've never been happier, truly. The tone is truly untouchable.”
Joey Diehl
“It’s an incredible unit. Pretty much everything I do is DI – synths, guitar, bass – and this is the best starting point for that because you have the most honest representation of the original performance and the instrument possible…there’s this weight to the low end and a sheen to the top end that’s very pleasing. It doesn’t get brittle, and the low end stays tight…it’s a fantastic DI.”
Tycho, Musician
“I’ve been using the RNDI for years – the best thing that was ever created. I play the bass guitar, and this is what I use all the time, for everything I do. For the Wailers band, we have about eight of them, and we use them for they keyboards and the triggers. I’m a huge fan of Rupert Neve.”
Aston Barrett Jr, Bass
The Wailers
“I'm still in disbelief as to how much of a difference there can be between two high quality direct boxes. This one is miles above everything else I have ever used. The difference is NOT subtle. Absolutely love it!”
Fred St-Gelais, Producer
Celine Dion, Marc Dupré, The Masked Singer
“…my secret weapon…it’s just something where I have no words for it. The magic of the color…it goes down to 12Hz, or 10Hz…you can’t believe the sonic colors you get out of it.”
Snow Owl
The World of Hans Zimmer
“I had quite literally no expectations of a DI changing my sound. And what happened was actually mind blowing. I got the RNDI-8 and RNDI-S installed, connected all the gear, flipped on phantom to power them and hit the first note on the PS-3100 and it was like I had wool earmuffs taken off - everything was so damn clear. There was clarity to it. I always heard the sound before, but now I was experiencing the sound. At the risk of sounding too much like a nerd, the DI’s made making music a full body experience.”
Six Missing
“Takes my pedalboard to the next level of clarity and headroom.”
“Excellent piece of gear. Very solid construction, zero noise, crystal clear signal.”
“I did some tracking last night with a Korg Grandstage through the RNDI-S and holy smokes brothers and sisters this box is amazing. Normally I add a lot of pro grade plugins on my piano track, but with this box in front of it, I added nothing and it sounded perfect. So good in fact, I had to come here an write this review. The price is steep but worth it. If your looking for the best DI on the market - you've found it.”
“WOW. So THAT is what my Nord is supposed to sound like. So THAT is what my Montage should sound like. So THAT is what my bass and wurly should sound like. Game changer.”
“As far as my guitar amp went (and its tone, not so much my talent!), the RNDI-S skyrocketed it to the next dimension; the place I'd been trying to coax it for a while now without success. I used to get so frustrated with that amp, which I felt was the culprit in a closed-off, dull, and sluggish sound. It seems that the Neve here fixes whatever issue in the signal chain that was preventing the amp from singing its fullest song. The resulting guitar sound now saturates completely and lights up the whole room - not just the inside of the cabinet. I was pretty floored by it all. I will just say that for the next few months or so, I will probably be getting out of bed in the morning thinking of doing things now made possible in my setup by this amazing machine.”
Customer Reviews via sweetwater.com
SPECIFICATIONS & DOWNLOADS
NOISE
Measured Output, un-weighted, 22 Hz - 22 kHz, source impedance 150 Ohm.
Better than -110 dBV
INPUT IMPEDANCE
Instrument Setting: 2.2 Meg Ohm
3.5 mm Input: 95 Kilohm
OUTPUT IMPEDANCE
Less than 40 Ohms
FREQUENCY RESPONSE
+/- 0.25 dB from 30 Hz - 63 kHz
+/- 1 dB from 12.5 Hz - 120 kHz
-3 dBu @ 5 kHz
MAXIMUM INPUT LEVEL
Instrument = +21 dBu (typical)
MAXIMUM OUTPUT LEVEL
+11.5 dBu output at maximum input level
TOTAL HARMONIC DISTORTION AND NOISE
@ 1 kHz, -20 dBu Input Level, no load : 0.009% Typical (2nd and 3rd Harmonic)
@ 1 kHz, +20 dBu Input Level, no load : 0.35% Typical (2nd and 3rd Harmonic)
@ 20 Hz, -20 dBu Input Level, no load : 0.9% Typical (2nd and 3rd Harmonic)
CROSSTALK @ 10 kHz
Instrument Input: -115 dB
3.5 mm Input: -108 dB
POWER REQUIREMENTS
Phantom power, 4.5mA @ +48VDC
WEIGHT
1.5lbs
DIMENSIONS
7” wide x 5” deep x 1.75” high
MOUNTING OPTION
19” Rack Shelf, 4 hole pattern (bottom of unit) for 6-32 machine screws
FREQUENTLY ASKED QUESTIONS
Yes, you can run a full +21 dBu line level signal into the RNDI-S, either through the L-R inputs or the 3.5mm stereo jack.
No. It is true that the higher input impedance of an active DI will generally result in greatly enhanced frequency response on a passive bass, but there are still advantages to an active DI on active basses as well. We recommend testing for yourself and letting your ears decide what tool works best.
The following may also be of interest:
RNDI Active Transformer Direct Interface
RNDI-8 8 Channel 1U Direct Interface
The Shelford Channel