Rupert Neve Designs RNDI-8 Eight Channel Active Transformer Direct Interface User Guide
- June 12, 2024
- Rupert Neve Designs
Table of Contents
Rupert Neve Designs RNDI-8 Eight Channel Active Transformer Direct
Interface
RNDI-8 Specifications
- Input Impedance (ZIN) Instrument Input: -10dB PAD Engaged – 2.2 Megohm
- Output Impedance (ZOUT): 200 Kilohm
- Maximum Input Level @ 1kHz Instrument Input -10dB PAD Engaged: +21 dBu
- Maximum Output Level @ 1kHz: +31 dBu
- Frequency Response (30 ft. output cable, 10k equivalent load): +/- 0.25 dB (28 Hz – 50 kHz), +/- 1dB (14 Hz – 90 kHz), -3dB (5 Hz)
- Noise (Measured Output, Un-weighted BW 22Hz – 22kHz, Source Impedance 150 ohms): Better than -110dBV
- Total Harmonic Distortion + Noise (THD+N%): 0.35% Typical (2nd and 3rd Harmonic) @ 1 kHz, +20 dBu Input Level, 0.009% Typical (2nd and 3rd Harmonic) @ 1 kHz, -20 dBu Input Level, 0.9% Typical (2nd and 3rd Harmonic) @ 20 Hz, -20 dBu Input Level
- Power Requirements: Phantom Powered, 4.5mA Per Channel @ +48VDC
- Rack Mounting Option: 19″ reversible bolt-on rack ears (1 RU)
Front Panel
The front panel of the RNDI-8 includes various controls and indicators for each channel. Please refer to the user manual for detailed instructions on using the front panel controls.
Rear Panel
The rear panel of the RNDI-8 features multiple input and output connectors for each channel. Please refer to the user manual for detailed information on the rear panel connections.
RNDI-8 Overview
The RNDI-8 is an eight-channel active transformer direct interface that provides high-quality audio signal conversion between instruments and recording devices. With its versatile features and reliable performance, it is suitable for professional audio applications.
Usage Notes
Before using the RNDI-8, ensure that it is properly connected to your
instruments and recording devices according to the provided user manual.
Follow the recommended input and output settings for optimal performance.
Make sure to engage the -10dB PAD when connecting instruments with high output
levels to prevent distortion. Adjust the input and output levels accordingly
to achieve the desired audio signal balance.
For best results, keep the RNDI-8 away from sources of electromagnetic
interference and ensure proper grounding. Regularly check and clean the
connectors to maintain good signal integrity.
Refer to the user manual for additional information on troubleshooting,
maintenance, and advanced usage techniques.
RNDI-8 Specifications
- Input Impedance (ZIN)
- Instrument Input 2.2 Megohm
- -10dB PAD Engaged 200 Kilohm
- Output Impedance (ZOUT) Less than 40 Ohms
- Maximum Input Level @ 1kHz
- Instrument Input +21 dBu
- -10dB PAD Engaged +31 dBu
- Maximum Output Level @ 1kHz +11 dBu
- Frequency Response (30 ft. output cable, 10k equivalent load)
- +/- 0.25 dB 28 Hz – 50 kHz
- +/- 1dB 14 Hz – 90 kHz
- -3dB 5 Hz
- Noise (Measured Output, Un-weighted BW 22Hz – 22kHz, Source Impedance 150 ohms) Better than -110dBV
- Total Harmonic Distortion + Noise (THD+N%)
- @ 1 kHz, +20 dBu Input Level 0.35% Typical (2nd and 3rd Harmonic)
- @ 1 kHz, -20 dBu Input Level 0.009% Typical (2nd and 3rd Harmonic)
- @ 20 Hz, -20 dBu Input Level 0.9% Typical (2nd and 3rd Harmonic)
- Power Requirements
- Phantom Powered 4.5mA Per Channel @ +48VDC
- 19” Rack Mounting Option 1 RU reversible bolt-on rack ears
All specifications are typical
Front Panel
Rear Panel
RNDI-8 Overview
The RNDI-8 is comprised of eight isolated RNDI channels. It is designed to provide instrument direct injection (electric guitar, bass, keyboard, piezo pickup, etc). The discrete Class-A circuit topology found in the RNDI-8 is based on Mr. Rupert Neve’s custom transformers, resulting in outstanding sonic performance. Each channel of the RNDI-8 can handle input levels up to +21dBu with-out clipping, while the low impedance transformer-coupled output allows the RNDI-8 to drive long lines with minimal loss. The RNDI-8 chassis’ steel construction is designed to stand up to the rigors of stage and studio use.
Usage Notes
Power needs to be supplied independently to each channel of the RNDI-8 by
standard 48V Phantom Power via the XLR output connectors. 48V Power Status is
indicated by eight independent front panel LEDs. Avoid placing this direct box
near strong elec-tromagnetic fields (such as those radiated by power
amplifiers) to reduce any chance of picking up noise. If you are experiencing
hum on the RNDI-8 outputs, try engaging combinations of GND LIFT (located on
the front panel) and PIN 1 ISOLATE (located on the rear panel) as well as
ground lifts on other devices in your signal chain. If this doesn’t alleviate
the issue, remove individual devices to isolate the source of the problem.
The RNDI-8 converts the high-impedance, instrument-level signals to a
balanced, low-impedance output which can be sent to a separate mic preamp. In
addition, the 1/4” THRU jack is available to connect each channel of the
RNDI-8 to amplifier input. To guarantee the best performance, we recommend
utilizing the best available cables and mic preamps.
User Guide P /N: 775-00038 Rev. A