The ultimate dynamics, tone, and stereo field control for your 2-buss.
Based on the high voltage, discrete, and class-A signal paths made famous in the 5088 Mixer, the Rupert Neve Designs Portico II Channel 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 MBP quickly became a favorite of mix engineers, tracking engineers, and even FOH engineers. From mixing bass-heavy EDM to a delicate master of a chamber ensemble, it has something to offer everyone – no matter the use or genre.
Classic Design, Evolved
With input and output transformers designed and implemented by Mr. Rupert Neve, the high-voltage 72V topology found in the Master Buss Processor will integrate flawlessly with virtually any system. Additionally, the MBP incorporates mastering-grade detented pots throughout to fine-tune its revolutionary dynamics, tone, and stereo field controls. This new topology is a significant evolution of Mr. Rupert Neve’s classic designs with appreciable benefits to headroom, dynamic range, distortion, noise, slew rate, bandwidth, and accuracy while still providing the sweet, musical performance that has been a part of countless recordings.
The MBP’s two compressor sections allow virtually limitless possibilities in dynamics for either dual mono or stereo sources, with controls for ratio, threshold, attack, release, blend, side chain HPF, limit, and make-up gain. When engaged, the compressor section can be used in both feed-forward and feed-back modes to provide a transparent “modern” response (feed-forward), or a smoother, more musical “vintage” response (feed-back). Peak mode alters the compressor’s attack to react to peak transients with a roughly .1ms response time. When the Peak switch is disengaged, the compressor responds to the RMS signal in conjunction with the attack and release settings.
SC HPF inserts a high pass filter at 125 Hz into the side chain to deal with intense low frequencies that may skew the response of the VCA with certain songs and instruments. And lastly, Blend creates a parallel mix between the compressed and dry signals. By mixing the compressed and dry signals, it is possible to increase the volume of quieter elements in the source material (for instance, delicate snare brushing on a track with much louder hits), while maintaining a natural dynamic feel for the louder elements.
The MBP also features an extremely versatile, transparent, and musical limiter. At first glance, one might scoff at the single knob operation – however, this limiter is extremely intelligent, knowing how to appropriately respond to the various signals presented to it. Our new Adaptive Release Technology is behind this revolutionary performance. Using a blend of release time constants, this limiter will simultaneously respond quickly to transient material (such as the “snap” of a snare drum) and slowly to more sluggish signals (such as a bass guitar). This configuration allows the limiter to grab a transient and let go just an instant later, while also dealing with more constant signals in a slower, more musical way.
In this manner, the MBP’s limiter can provide a much more aggressive amount of limiting than typically possible, while maintaining the essential character of the music and remaining free of the modulation distortion usually found in a fast-acting limiter. Additionally, the limiters share the same discrete, class-A gain module and VCA with the compressors, so using the Limiter does not introduce more stages that the music would have to pass through.
The Stereo Field Editor
The stereo field editor on the MBP takes traditional M-S techniques to new heights with width, depth, and corresponding bandpass filters.
The width control enables the user to increase or decrease the width of a stereo image (wide/mono) and adjust the amount of ambiance inherent in the recording. As the width control is rotated toward wide, the amount of difference material is boosted, often resulting in more ambient material, and accentuated stereo reverbs. Conversely, the stereo field is contracted when rotated 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. The depth control adjusts the spatial positioning of elements in the sound stage. Center-panned elements like solo instruments or vocals can be brought forward in a mix, in relation to supporting instruments. In many cases, these same elements may be virtually eliminated without adversely affecting the music bed. Used in conjunction, the depth, and width control effectively alter the perceived room ambiance and dimension.
To fine tune the SFE, there are individual filters that select what frequency information is reintroduced from the width and depth circuits, thus tailoring each effect to a specific bandwidth. And by engaging the SFE TO COMP button, Mid and Side signals can each be routed to the MBP’s two compressors, allowing the unit to operate in full M-S mode (as opposed to standard L-R operation).
WHAT IS SILK?
Every mix deserves its own treatment. The Silk & Texture circuit allows you to fine-tune the amount (and type) of harmonic content in the output stage. This means your signal can be adjusted from extremely transparent to thick, weighty settings that produce several times the amount of sonic color found in Rupert’s vintage modules – and in two very unique modes. No matter what sound you’re looking for, Silk will help get you there.
Drive the mix hard, choose your Silk flavor, and crank the Texture knob for a rich, saturated, vintage vibe – or disengage Silk entirely for clear, wide-open sonic beauty. The choice is yours.
When you apply SILK RED, you’re enhancing harmonic content generated by the highs and high mids of your source. This adds a sparkly sheen to the top end and is often ideal for sources including vocals, snare, strings, pianos, and other acoustic instruments.
With SILK BLUE, you’re enhancing harmonics generated by the lows and low mids of your source. This tends to “beef up” a signal from the bottom up, making it a great choice for drums, bass guitars, heavy electric guitars, male vocals, and synthesizers.
This 31-detent potentiometer adjusts the level at which the compressor begins to attenuate the signal and is fully variable within a signal level range of +20dBu to -30 dBu. If the compressor input signal level exceeds the set threshold level, compression will occur.
This 31-detent potentiometer adjusts the compressor slope between 1:1 to 40:1.
This 31-detent potentiometer adjusts the mix ratio of the uncompressed (dry) signal with the compressed (wet) signal. When Blend is fully counter-clockwise (CCW), only the uncompressed signal is audible. When Blend is fully clockwise (CW), only the compressed signal is audible. Setting Blend anywhere between 0% and 100% achieves parallel compression.
This illuminated push-button switch engages the compressor-limiter section on its respective channel. Engaging or disengaging the “Comp In” button never affects SILK status and will not affect SFE status unless SFE to COMP is engaged.
This illuminated push-button switch toggles the PIIMB’s hard-wire bypass on both channels.
This illuminated push-button switch toggles between two different compression modes: Feed Forward and Feed Back. The distinction between these two types of compression is that the side-chain detector of a feed-forward compressor is fed from the compressor input, before the gain control element, while the side-chain detector of a feed-back compressor is fed from the compressor output, after the gain control element.
This 31-detent potentiometer provides two different functions. When used with the compressor, the Gain control acts as standard Make-Up Gain, allowing the user to add gain to the compressed signal to match the bypassed signal level. When used in the context of the PIIMB limiter, the Gain control allows the user to set the desired “ceiling” of their mix (in dBu) with the “Limit” potentiometer. Once the Limit potentiometer is set to the desired maximum level, the user can increase the Gain until the average mix level hits the desired loudness. The Gain control will drive the level of the mix up to the set Limiter threshold, but will not exceed it.
This 31-detent potentiometer sets how quickly the compressor will attenuate to the input signal once it exceeds the set threshold. When set to its fastest setting (20 ms), the compressor can attenuate the leading edge of a transient, like the initial strike of a drum stick on a snare drum. By compressing the initial strike, the overall compression result will increase the emphasis on the snare’s decay or resonance. When set to slower attack settings, the compressor will ignore most of the initial transient and attenuate the drum’s decay instead, thereby increasing the emphasis of the drum stick hitting the snare drum.
This 31-detent potentiometer adjusts how fast the compressor will return to unity gain after the signal level crosses below the threshold. Generally, slower release times will minimize compression artifacts, especially when combined with slower attack times. Faster release times can be utilized to maximize apparent loudness.
S/C 125 Hz
This illuminated push-button switch engages a 125Hz 12dB/octave Sallen Key High Pass Filter into the compressor-limiter side-chain. Removing low-frequency information from the compressor-limiter side-chain detector can help to minimize compressor pumping and over-compression of the rhythmic dynamic information that tends to reside in the lower frequency range: kick drums, bass guitar, etc. This usually results in a smoother compression characteristic.
RMS / PEAK
This illuminated push-button switch modifies the compressor side-chain detection. The default detection response is RMS (Root Mean Square) averaged, which better mimics the way our ears perceive loudness. PEAK mode detection responds more directly to the incoming compressor audio signal, which can be used to prevent clipping and maximize overall loudness.
The link control sums the side-chain information from both compressor-limiter channels, enabling Channel A’s controls as MASTER. While linked, both channels are directly controlled by Channel A’s controls.
This 31-detent potentiometer controls the threshold of the soft-clip limiter section. The limiter is disengaged until the user rotates the Limit potentiometer past the 3rd detent (+24dBu) from the fully clockwise (OFF) position. As the user rotates the threshold control counter clock-wise, the limiter’s release time gradually increases. This creates a smoother dynamic response as the amount of limiting increases. The limiter side-chain features a compound timing network that allows the limiter to respond equally well to quick transient material as it does to less dynamic program material. The limiter can be utilized as a maximizer by setting the Limit potentiometer to the desired maximum level in dBu, then increasing the amount of Gain until the desired program loudness is achieved.
Depth (engaged/disengaged with the ‘Depth In’ switch)
This 31-detent potentiometer adjusts the overall level of the center (mid) information within the SFE’s M-S encoding. The MIN (fully CCW) position will de-emphasize the center information within the stereo image, whereas the MAX (fully CW) position will emphasize the center information. If the Depth control is at the 12 o’clock “0” position, no Depth pro-cessing will be audible.
Width (engaged/disengaged with the ‘Width In’ switch)
This 31-detent potentiometer adjusts the overall level of the side information within the SFE’s M-S encoding. The MIN (fully CCW) position will de-emphasize the side information within the stereo image, whereas the MAX (fully CW) position will emphasize the side information. If the Width control is at the 12 o’clock “0” position, no Width processing will be audible.
This illuminated push-button switch engages the 4-position rotary switch that allows the user to select between four different EQ settings for Depth processing: Low Frequency (LF), Low Mid (LM), High Mid (HM), and High Frequency (HF).
This illuminated push-button switch engages the 4-position rotary switch that allows the user to select between four different EQ settings for Width processing: Low Frequency (LF), Low Mid (LM), High Mid (HM), and High Frequency (HF).
SFE to Comp
This illuminated push-button switch routes the Depth and Width information to Channel A and Channel B compressor paths, respectively, allowing the user to manipulate the dynamic content of the Mid and Side information. When engaged, the width and depth controls allow the user to blend the amount of compressed Mid and Side information that is mixed back into the audio path. While SFE to Comp is engaged, the stereo compressor is only available for SFE dynamic processing and is not operational within the main audio path.
This illuminated push-button switch toggles through the available SILK transformer harmonic saturation modes: OFF, RED, and BLUE. Red Silk has a high-frequency emphasis associated with the transformer harmonics, while Blue Silk has a low-frequency emphasis associated with the transformer harmonics.
This 31-detent potentiometer allows the user to adjust the amount of Silk transformer saturation added to the signal path when Silk Red or Blue modes are engaged.
Gain Reduction Meter
This 16-segment LED bar-graph meter indicates compressor-limiter gain reduction, indicated in dB. After 4 dB of attenuation, the LEDs turn to amber and after 8 dB, the LEDs turn red.
This 16-segment LED bar-graph meter indicates the output level, indicated in dBu. The top-most red LED is calibrated to illuminate at +25dBu, corresponding to the maximum output level of the Master Buss Processor.
Side Chain Send/Return
External compressor side chain sends and returns on 2 x TRS jacks. The send is always active and normalled to the return. NOTE: If the send and return are connected to a patchbay, the send should be normalled or connected to the return by default, as the compressor will not trigger if the return has no signal.
Internal Universal Power Supply
EIC connection for worldwide AC power from 100-240V embedded in the 2U rack-mountable chassis.
Frequency Response (Compressor and SFE Bypassed, Unloaded)
5 Hz to 100 kHz: +/- 0.5dB typical
120 kHz: -3dB typical
Maximum Output Level (Compressor and SFE Bypassed, Unloaded)
20 Hz to 40 kHz: +25 dBu typical
Total Harmonic Distortion and Noise
1 kHz, +20 dBu: Less than 0.003% typical
20Hz, +20 dBu: Less than 0.10% typical
20 kHz, +20 dBu output: Less than 0.010% typical
Threshold: -30 dBu to +20 dBu
Ratio: 1.1:1 to 40:1
Blend: 0% to 100% Compressor
Gain: 0 dB to +20 dB
Attack: 20 mS to 80 mS
Release: 100 mS to 3.0 S
AC Power Consumption
85 Watts Max
5 x 20mm Bussman type GDA 2.5A, Fast Acting, Ceramic
Product Dimensions (H x W x D)
3.5” (8.9 cm), 19” (48.3 cm), 12” (30.5 cm)
Shipping Dimensions (H x W x D)
5” (12.7 cm), 23” (58.5 cm), 12” (31 cm)
20 lbs (9.1 kg)