Neve Portico II Master Buss Processor

Features

        The Rupert Neve Designs Portico II Master Buss Processor is an all discrete, class A, high voltage stereo buss processor housed in a 2u 19” rack. Its heavy aluminum faceplate is packed with 20 of what Neve calls ‘mastering grade detented pots, and another 16 push-button led switches. The output meter is also of the LED sort, offering 24 steps of both output level and gain reduction for each channel. The Neve mastering compressor’s discrete gain stages are married to custom input and output transformers, it’s output transformer, according to the manual, the largest toroidal transformer ever utilized by Neve in a line level device. The Neve MBP outputs an incredible +25dBu from its balanced XLR outputs, exceeding the +24dBs trim available on most mastering quality A/D conversion. The processor is divided into three main sections: compressor channel A, compressor channel B and the sound-field editor. The two compressor channels can be operated separately with completely individual controls, or the channels can be ganged and the detector summed with the press of the ‘link’ button. Included in each compressor circuit is a peak limiter and a distortion circuit called 'silk'.  The sound-field editor is a mid-side equalizer with fixed frequency points, labeled LF, LM, HM and HF. 

        The Neve MBP’s limiter offers only a threshold control ranging from +24dBu to +10dBu and allows a full bypass by turning the knob fully clockwise. The limiter utilizes Neve’s Serial Adaptive Release Technology, which allows for adaptive release times relative to the time the threshold has been crossed. The release time also increases proportionally as the limiter’s control is turned counter clockwise toward its lowest threshold settings. This allows the possibility of influencing limiting characteristics by increasing the input gain to the compressor circuit rather than lowering the limiter threshold. The Neve MBP’s limiter has a fixed attack time of .03ms, and utilizing a medium knee reaches 40:1 ratios just 3db above the threshold. In practice, these features allow engineers to transparently catch transients before they’re able to clip the input of analogue to digital conversion. The limiter circuit shares the discrete gain stages and VCA’s with the compressor to offer the simplest signal path possible.

        The compressor offers tons of flexibility in its controls, rivaling the most fully featured DAW plugin. This includes an RMS/peak mode, a 125hz side chain filter (150hz in early models), a blend circuit, and both feedback and feedforward modes. The ratio starts at 1.1:1 and maxes out at a brick wall 40:1. The first two detents on the ratio knob offer some of the most gentle and transparent compression I’ve experienced and are well suited for adding a bit of density and depth to a well-balanced master. Feedback mode offers very classic sounding and smooth buss compression, while the feedforward mode imparts a bouncier, almost SSL G384 like character. 

        The two silk texture modes add distortion and harmonics reminiscent of Neve’s vintage class A designs (think 1063). The blue mode enhances low and mid frequency content, adding distortion up to 3.5% THD. The red mode enhances mid and high frequency content, adding distortion up to 2.5% THD. 

IN USE

        In mastering, best results are obtained by utilizing the simplest signal path. For me this is often my Knif Soma directly into my Knif Vari Mu II, followed by a digital limiter. If more color is desired I’ll place a tone heavy compressor at the front of my chain, like the Tube Tech SMC 2B or Foote P4S. Lately, however, I’ve been on the search for an ultra-transparent compressor to follow my Knif VM-II, just to add a final glaze of closeness and depth. It was to fill this role that the Neve Portico II MBP was added to my racks. 

       Although the Neve Portico II MBP has some of the most transparent compression characteristics available, it has turned out to be poorly suited for this job.  This is due to the fact that regardless of its settings, the MBP manipulates the stereo image in an unaesthetic way. This manipulation is less obvious when the compressor is in linked mode but I still find it unacceptable at the end of my chain. It's not just the compressor that manipulates the stereo image, I also find the silk distortion circuits to widen the image in a nonlinear way. The red circuit adds considerable width to high frequency content, and the blue circuit to low mids, leaving the track sounding honky and unbalanced. 

       Where the Neve truly excels is placed first in the analogue chain. Here, the stereo image issues are seemingly corrected by the Knif VM-II later in my chain. In use, I find that a light amount of limiting from the Neve allows my Knif compressor to more efficiently and aesthetically glue tracks. The trick is to gently grab all the high crest factor transients with the Neve to allow your end of chain buss compressor to spend less time in recovery. I find this configuration allows for louder masters with noticeably less compression artifacts. I also find the silk distortion circuits to work very well at the front of my analogue chain as the nonlinear equalization artifacts were also smoothed out by my primary buss compressor. 

Limitations

            Most of the limitations of the Neve MBP can be attributed to packing so many features into a 2u box, while others are likely due to design tradeoffs intended to allow this unit to be useful for recording and mixing engineers as well as mastering engineers.

            My biggest grievance with the Neve Master Buss Processor is that it’s ‘mastering grade detented pots’ are not precise enough for use in mastering. When the MBP compressors are in multiple mono mode, a loss of center focus and unnaturally wide stereo image make it apparent that the detented pots are poorly matched between channels. To work around this, one must set the compressor by summing the mix into mono and tweaking the ratio, blend and threshold pots on both channels until a sound-field meter, like the one in Izotope Insight, reads as a perfectly vertical line. Often this means carefully setting the detented pots between detents. I found this issue to be so frustrating and time consuming that I nearly returned the Neve MBP during my demo period. Even when set as close as possible, all content in multiple mono mode loses focus in the center of the mix.

       The 125hz side-chain filter, although lower in frequency than its original 150hz setting, still feels too high for mastering use. When inserted, mixes feel too high frequency forward even when the compressor is taking minimal gain reduction.  Therefore, one can conclude this filter is here more for a vocal or instrument buss than it is for mastering. A selection between several eq points would be a greatly appreciated addition for the MBP in a mastering chain.

            Another major limitation of the Neve MBP is that its sound-field editor cannot be assigned to the compressor sidechain. This feature would allow the compressor to have much more spectral flexibility, and offer something of a variable stereo link to the compressor circuits by allowing a narrowed version of the mix to hit the detectors in multiple mono mode. Honestly, I can't find much of a use for the sound-field editor at all. On the dance and soundtrack content I generally master, even the lightest settings add a phasey malaise to my masters. 

            Finally, I find the LED gain reduction meter to be poorly designed for mastering. The meter reads 24dB of gain reduction in 1dB increments, offering desirable resolution for a mixing or recording engineer but not near enough granularity for mastering. When the compressor and limiter are set properly in my signal chain, the -1db LED is never illuminated. As this compressor has such transparent compression characteristics, I find it necessary to check a digital meter in my DAW to ascertain when the Neve Portico II MBP starting to take gain reduction.   

Strengths

       The strength of the Neve Master Buss Processor is its incredible flexibility. It can be used by a recording or mixing engineer in multiple mono mode to compressor mono tracks, or by a mastering engineer as a capable buss compressor. The astonishing transparency of its compressor circuit means that it can be set well on essentially any content. 

       Another strength is its silk distortion circuits. Although they're easy to take too far, when used sparing they can effectively solve both equalization and closeness issues with the turn of a knob. I find that the difference between a good and great dance master is often just a bit of aesthetic distortion, and the Neve is a very capable tool for this task. 

Final Thoughts

       I wouldn't want the Neve to be my only buss compressor, but its well-equipped and has proven very useful in my mastering chain.  It feels like Neve needs to make a dedicate mastering version of its master buss processor, with switches instead of detents, more frequency selection on the compressor side-chain filter and a higher resolution meter. Thanks to the talented EDM Mastering Engineer Saif Bari for suggesting the Neve MBP.

Strengths

Very versatile
Low Ratios offer transparent compression
Intelligent Limiter
Great sounding ‘silk’ distortion modes

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