Rupert Neve Designs Portico II Master Buss Black

Based around the high voltage, discrete and class-A signal paths made famous in the 5088 Mixer and the Portico II: Channel, the Portico II Master Buss Processor is creative tool that redefines the boundaries and limitations of traditional 2-channel compression and limiting.

With input and output transformers designed and implemented by Mr. Rupert Neve, the high-voltage 72V topology found in the Master Buss Processor (MBP) 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 for the sweet, musical performance that has been a part of countless recordings.

The Compressor
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. With the stereo link control engaged, Ch. A settings act as the master control for convenient operation. 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 250 Hz into the side chain to deal with intense low frequencies that may skew the response of the VCA with certain songs and instruments. “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.

To further control the side chain, there is also an insert “send” and “return” that may be paired with an external EQ or other filters for additional manipulation. The “return” may also be used as a “Key” input for ducking one signal to another (for instance, a voice-over keying the compressor to duck a background music track).

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 ambience 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. If the phase of one of the input channels is then reversed the mono content may 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 interplay between the stereo field editor′s other controls, listening and experimentation are essential for the best results.

The Limiter
The Portico II Master Buss Processor 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 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.

Specifications:

Frequency Response:
 Main Output, no load,
             –3 dB @ 4 Hz
             –3 dB @ 120 kHz
Maximum Output Level:
 Maximum output from 20 Hz to 40 kHz is +24.5 dBu.

Total Harmonic Distortion and Noise:
    @ 1kHz, +20 dBu output: Better than 0.006%
@ 20Hz, +20 dBu output: Better than 0.20%
- As above, Silk Blue Engaged, Texture fully CW: Better than 2.5%
- As above, Silk Red Engaged, Texture fully CW: Better than 3.5%
@ 20kHz, +20 dBu output: Better than 0.020%

Slew rate Better than 4 V/uS

Compressor
Threshold:  Variable from -30dBu to +20dBu
Ratio:      Variable from 1.1:1 to 40:1 (LIMIT)
Blend:      Variable from 0% to 100% Compressor
Gain:       Variable from -6 dB to +20 dB
Attack: Variable from 20 mS to 75 mS (0.1mS with “FAST”)
Release:     Variable from 100mS to 2.2 Seconds

Power Consumption
.65A @ 117 VAC, .35A @ 220 VAC

Fuse
5mm x 20mm, 2.5 Amp, fast acting, ceramic body – Bussman type GDA 2.5A or equivalent

Size 3.5”H (2U), 19”W, 12”D
Shipping Size 5”H (2U), 23”W, 12”D
Shipping Weight 20 lbs