RUPERT NEVE DESIGN PORTICO II MASTER BUSS PROCESSOR Compressor/limiter

Compressor/Limiter

Based on the high-voltage, discrete, Class-A signal paths made famous in the 5088 Mixer and the Portico II Channel, the RUPERT NEVE DESIGNS PORTICO II MASTER BUSS PROCESSOR is a creative tool that redefines the boundaries and limitations of traditional 2-channel compression and limiting. Though originally developed for mastering applications, the RUPERT NEVE DESIGNS PORTICO II MASTER BUSS PROCESSOR has quickly become a favorite of mixing engineers, tracking engineers and even FOH engineers. From mixing bass-heavy EDM to delicately mastering a chamber ensemble, it has something to offer everyone, regardless of use or genre.
With Rupert Neve-designed and manufactured input and output transformers, the 72V high voltage topology found in the RUPERT NEVE DESIGNS PORTICO II MASTER BUSS PROCESSOR will integrate seamlessly with any system. Additionally, the RUPERT NEVE DESIGNS PORTICO II MASTER BUSS PROCESSOR incorporates mastering-grade detented pots for fine-tuning its revolutionary dynamics, tone and stereo field controls. This new topology represents a significant evolution of Mr. Rupert Neve's classic designs with appreciable advantages in terms of headroom, dynamic range, distortion, noise, slew rate, bandwidth, and accuracy, while maintaining the sweet musical performance that has been a part of countless recordings.

The Compressor

The two compressor sections of the RUPERT NEVE DESIGNS PORTICO II MASTER BUSS PROCESSOR provide virtually endless dynamic possibilities for dual mono or stereo sources, with controls for ratio, threshold, attack, release, blend, HPF side chain, limit gain, and make-up gain. When engaged, the compressor section can be used in either feed-forward or feed-back mode to provide a transparent modern response (feed-forward) or a smoother, more musical vintage response (feed-back). Peak mode alters the attack of the compressor to react to peak transients with a response time of approximately 1ms. When the Peak switch is disengaged, the compressor responds to the RMS signal along with the attack and release settings. SC HPF inserts a 250 Hz high pass filter into the side chain to deal with intense low frequencies that might otherwise skew the VCA’s response with certain tracks and instruments. “Blend” creates a parallel mix between the compressed and dry signals. By blending the compressed and dry signals, you can increase the volume of quieter elements in the source material (e.g. the delicate snare ghost notes on a track with much louder hits), while still maintaining a natural dynamic feel for the louder elements.
To further control the side chain, there is also a “send” and “return” insert which can be coupled with an external EQ or other filters for further manipulation. The “return” can also be used as a “key” input for ducking one signal to another.
With the stereo link control engaged, ch.A acts as the master control.

The Limiter

The RUPERT NEVE DESIGNS PORTICO II MASTER BUSS PROCESSOR also features an extremely versatile, transparent, and musical limiter. At first glance, one might doubt the single knob, however, this limiter is extremely intelligent, knowing how to appropriately respond to various signals. Adaptive Release Technology is at the heart of this groundbreaking performance. By using a blend of release time constants, this limiter will simultaneously respond quickly to transient material (like the “snap” of a snare drum) and slowly to slower signals (like a bass guitar). This setup allows the limiter to grab a transient and let it go just an instant later, while also dealing with more constant signals in a slower, more musical way. In this way, the RUPERT NEVE DESIGNS PORTICO II MASTER BUSS PROCESSOR’s limiter can provide a far more aggressive amount of limiting than is typically possible, while still maintaining the essential character of the music and remaining free from the modulation distortion usually present in a fast-acting limiter.
Typically there is a tradeoff between how quickly a limiter can react and the amount of modulation distortion in the lower frequencies. This is due to the fact that lower frequencies find their way into the side chain signal, switching the compressor on and off very quickly, which ends up modulating the overall signal. This is interesting to watch with sine waves, but is quite undesirable with music. The RUPERT NEVE DESIGNS PORTICO II MASTER BUSS PROCESSOR has no such tradeoff, being able to have the best of both worlds: a fast, snappy response while maintaining the integrity and smoothness of the low end. In addition to the adaptive constant time circuitry, the release time is also varied with the position of the knob. When the knob is turned counter-clockwise, the release time is increased accordingly, as one would typically want a longer release time with a greater amount of reduction.
The new limiter found in the RUPERT NEVE DESIGNS PORTICO II MASTER BUSS PROCESSOR is designed to respond at a speed of 0.03 mS in order to reduce the first half of a 20 kHz waveform over threshold. It has an initial ratio of “medium knee” and within 3 dB of the threshold it reaches a ratio better than 10:1. A soft clip circuit catches any transients that might be in the “knee” when the threshold knob is set quite high. Both the limiter and soft clipper are removed from the circuit with the knob set fully clockwise. The release times are fully automatic and adjusted according to the average depth of limiting and duration of transients above threshold. The limiters share the same Class-A discrete gain module and VCA with the compressors, so use of the Limiter does not introduce more stages that music has to pass through. This combination of features provides exceptionally transparent limiting and often allows for twice the reduction as other limiters before objectionable artifacts become apparent.

The Stereo Field Editor

The RUPERT NEVE DESIGNS PORTICO II MASTER BUSS PROCESSOR's Stereo Field Editor brings traditional M-S techniques to new heights with width, depth, and corresponding band-pass filters.
The Stereo Field Editor allows the user to increase or decrease the width of a stereo image (wide/mono) and adjust the amount of atmosphere inherent in the recording. When the width control is turned toward wide, the amount of difference material is increased, often resulting in more ambient material and accentuated stereo reverbs. Conversely, the stereo field is contracted when turned to mono, and, if the left and right channels are highly coherent (i.e. both channels include closely similar material that is in phase), this mono content is enhanced. If the phase of one of the input channels is then inverted, the mono content can be virtually eliminated. Because the amount of effect the width control has is entirely dependent on the amount of stereo information in the original source material and the interaction between the other stereo field editor controls, listening and experimenting are essential for the best results.
The depth control adjusts the spatial positioning of elements in the soundstage. Center panned elements like a lead instrument or vocal can be brought forward in a mix, relative to supporting instruments. In many cases, these same elements could be virtually eliminated without adversely affecting them. Used in conjunction, the depth and width controls effectively alter the ambience and perceived room size.
To fine tune the SFE, there are individual filters that allow for fine tuning of what information is being reintroduced by the depth and width circuits, thereby tailoring each effect to a specific bandwidth. For instance, if one wanted to increase the amount of low frequencies in the center image, engaging the SFE Depth and Depth EQ, set to LF, filters everything in the Mid signal but what is below the filter point (in this case, 250 Hz), and once reintroduced to the original would result in a perceived increase in low frequencies in the center image. It is also possible to do the same thing with the Width EQ, except increasing width, while cutting it, removes low frequencies from the sides, narrowing the low frequency perception to the center. Using the Width EQ again, this time set to HM (or LM as the case may be), increasing the amount of side-band passed information can provide a wonderful spread of instruments, reverb, and background vocals, giving the illusion that the sounds are spreading further, enveloping the listener.
Another technique available on the SFE is the routing of the Mid and Side signals to channel A and channel B’s compressors, respectively. Now any amount of depth or width being introduced is first routed to the compressors, enabling the user to utilize the compressor’s features on the Mid and Side information. Now it is possible to not only increase side information, but use the compressor to bring up some of the low-level information, or allow the user to tame an overly expressive lead vocal. With the addition of using the EQ section on the depth and width, a wide array of tools is available to the engineer.

Specifications

• Powerful 2-channel compressor / limiter / stereo field manipulator
• Full-featured compression sections for both channels, including attack, release, ratio, and threshold
• Side chain capability with high-pass filters for both compressors
• Feed-back/Feed-forward controls allow you to select modern and vintage compression sounds
• Texture control with 2 Silk modes to add classic Neve warmth
• Blend controls allow you to mix the dry signal back into your compression, preserving transients while adding punch
• Simple and highly musical 1-Knob Limiter “Adaptive Release Technology” allows for limiting that does not alter or influence levels below threshold
• Stereo Field Editor section includes independent controls for width and depth as well as width and depth EQ