Rupert Neve Designs Portico II Master Buss Converter

Whether you’re tracking, printing mixes, or mastering, the Master Buss Converter is a revelation in quality and functionality of A-D conversion technology. The analog drive circuitry allows the MBC’s converter to be fed by either a class-A transformerless path for maximum transparency, or by custom inter-stage audio transformers with variable Silk for a wide variety of tonal enhancements. Coupled with an astonishingly musical limiter, the MBC is always the best choice to capture your analog signals with breathtakingly three-dimensional accuracy.

A Long Time Coming
With over seven decades of analog circuit design experience, Mr. Rupert Neve had never considered a converter worthy of his hallmark until the release of the RMP-D8 Dante-connected microphone

preamplifier in 2018. While the RMP was primarily designed as a mic preamp, its adoption by engineers at the highest levels of recording, mastering, and touring as their preferred converter led to the development of the MBC, creating a new standard for PCM conversion quality.

Dual Path Analog Design
As the last link in the analog chain before digitization, converter drive circuitry is critical in determining the imprinted digital sound quality. From the ground up, the MBC was designed for reference performance regardless of genre or desired sonic character, and the key to this lies in the quality and adaptability of the analog drive circuitry.

For a bolder, more powerful imprint, a custom-designed inter-stage transformer with Rupert’s acclaimed Silk circuitry can be inserted to recreate the classic tonality of his vintage designs. Uniquely, unlike our audio transformers intended for line-level output, this new transformer is designed to achieve output transformer harmonic content characteristics at a level appropriate for input to the converter itself. With the addition of variable Silk, the engineer is able to precisely dial in the desired amount of harmonic content – with the Red mode highlighting harmonics in the mid and high frequencies, and the Blue mode accentuating harmonics in the low-end. From a subtle transformer tonality without Silk, to significantly more color than vintage modules with the Silk / Texture circuit fully pushed, the selectable transformer path fills your tracks with enhanced dimensionality and power.

When maximum transparency and fidelity is desired, the transformerless path provides extraordinary detail and clarity. While many transformerless circuits suffer from thin tonal balance and a lack of punch, the MBC’s Class-A circuitry was painstakingly designed to deliver a beautiful sense of clarity, with vibrant detail at both high and low frequencies. As an additional tonal palette to capture your tracks, the transformerless path is an essential complement to the weighty, classic sound of the transformer path. No matter what sonic character you’re seeking, the MBC can provide it at the push of a button.

Compound Active Release Analog Limiter
The challenge here was to design a limiter that could act as both a musical sculpting tool exceeding the quality of available plug-in limiters, while also being able to act as a transparent safety limiter for tracking or live performance & broadcast.

To achieve this, we refined our compound active release topology to enhance both the accuracy and musicality of the limiter response. The resulting limiter achieves both transparency and the capability of pushing the level of tracks or mixes without damage to the integrity of the source.
To further adapt the sound of the limiter, we’ve added a number of controls to fine-tune its response. The built-in Side Chain High-Pass Filter, sweepable from 20-250Hz, minimizes the limiter’s reaction to low frequencies, which tend to be more sustained in nature than high frequencies. The threshold control sets the maximum levels for your digital signal, and the variable release time constant alters the response characteristic to better fit different source material. To further push levels into the limiter, the class-A line amp stage is capable of adding 20dB of ultra-clean gain. The limiter may be used as a dual mono or stereo linked design via the Link switch, depending on the desired use.

Mastering-Grade Conversion
The MBC’s 24-bit/192kHz converters were developed after years of careful listening, and represent a further advancement of the design within the RMP-D8. The precision controlled internal clock’s minimal jitter and phase noise allow the converters to capture the complete performance of your music with a great degree of accuracy – simply put, the MBC creates an uncanny digital representation of your analog signals.

Make Connections
To connect into your interface or digital console, the MBC is equipped with AES, S/PDIF and TOSLINK outputs capable of simultaneous output to multiple destinations. The word clock output allows the MBC to act as high-end master clock for your entire setup, and the word clock input allows external sync to a separate master clock if desired. Finally, to seamlessly integrate the MBC into a multichannel conversion environment, four standard levels from -14dBFS to -20dBFS can be selected to accurately match your other converters. These Reference Level calibration standards are implemented with a superb degree of accuracy via high-precision resistors and relay-controlled stepped attenuation.

Ultra-Precise Metering
A pair of 22-segment meters provide extremely precise level metering of the input to the converter stage, utilizing a new design that represents the highest resolution LED metering in a Rupert Neve Designs product to date. For monitoring of the limiter’s gain reduction, there are 8-segment gain reduction meters designed to display transient reductions with a superb degree of accuracy. The level meters can be further customized with a 1-second or 3-second peak hold option.

• Selectable Analog Drive Paths
• The very best of class-A transformerless and custom transformer-coupled designs at the touch of a button.
• Transformer Path with Silk / Texture
• Add weight and punch with a dedicated custom inter-stage transformer before the converter. Silk / Texture allows you to dial in the harmonic content and drive saturation of this signal path.
• Class-A Transformerless Path
• Maximizes clarity and transparency of the input signal.
• Active Compound Release Analog Limiting
• Push your levels further with fewer artifacts than plug-ins, and introduce clip safety for tracking or broadcast.
• 24-bit/192kHz Reference Conversion
• Unparalleled analog capture with precision clocking using top-of-the-line chips.
• Multi-Standard Connectivity
• Connect to any of your digital devices with AES, S/PDIF and TOSLINK all simultaneously available.
• Precision Clocking
• Maximum accuracy with minimal jitter and phase noise, able to operate as a master clock or sync from another master.