Rupert Neve Designs Portico 5043V Compressor/Limiter Duo is a new and powerful approach to dynamic processing! This new addition to the Portico range is designed with both tracking and mixing applications in mind. The RND Portico 5043 embodies two independent Compressor-Limiters (Channels A and B) housed within a half rack, 1U module. They can be used independently or connected in sequence to provide two separate control slopes. When used independently, for example, as a stereo pair, linking the D.C. control circuits via a front panel Push-Button, enables the level of each unit, “A” and “B”, to be held in a constant relationship. Rear panel TRS connections are provided to link multiple 5043s. This linking may also be extended to the former AMEK CIB and DMCL units.
When used in sequence, the RND Portico 5043V can be configured easily to provide dual slope compression and limiting as suggested in the graphs below.
Any number of Portico modules that are equipped with the “TO BUSS” button may be sent to the BUSS input of the 5043 which makes it the ideal choice to form the core of a simple and cost-effective Portico mixing system. The Line input, when selected, provides a dedicated, transformer-balanced 10K impedance bridging input so that the 5043 may be inserted or included in any appropriate part of the signal chain at Console line-up level.
In order to control gain, a V.C.A. or Voltage Controlled Amplifier (or Attenuator) is used. There are many types of V.C. including the use of tubes, discrete and integrated solid state circuits and naturally non-linear devices, each one having its characteristic behavior that reflects sonically on the final performance, and gives it a character or signature that can be musically attractive or not! The Portico 5043 makes use of a very accurate, low noise, low distortion V.C.A. having, essentially, no signature of its own.
A part of the audio signal is rectified and smoothed to produce a suitable control voltage for the V.C.A. which has to respond very quickly and have low distortion. If the response is too fast, low frequency signals will themselves, be gain controlled! If the response is too slow, the signal will overshoot and the first few cycles will not get compressed. The speed and accuracy of the response, known as the “attack”, and the time frame that gain remains under the initial control, known as “release” or “recovery” and plays a large part in the way a compressor sounds.
All Rupert Neve Portico modules use input and output transformers and, almost entirely discrete component amplifiers. In fact the Line amplifiers on their own, inserted into the signal chain, are capable of enhancing the sonic quality of many signal sources, especially those of digital origin. These are some of the factors that enable, the Portico 5043, to work so unobtrusively within the context of a very high quality audio chain.
The Rupert Neve Designs Portico 5043 provides a choice of feed-forward or feed-back compression modes. The FB Button allows the user to switch between the two modes.