Best Compressor Modules

The Portico 543 from Rupert Neve Designs is a fully controllable compressor-limiter featuring feed-forward / feedback modes, Peak / RMS detection and a built in side chain high pass filter. There's nothing like a Rupert Neve design matched with a great set of features and the 543 combines that amazing warmth, precision and flexibility that only the Neve name could bring you.Built around Mr. Rupert Neve s custom transformer designs, each 543 module encompasses individually controllable threshold, attack, release, makeup gain, ratio, side chain HPF, Feed-Forward / Feed-back selection and Peak/RMS detection modes. With the compressor inactive, the 543 may be used as a transformer-coupled, high-performance line amplifier, and two 543 may be linked for stereo operation as well. The chassis is built to standard 500 series specifications, with power and I/O provided by the rack.Different Control TypesIn order to control gain, a VCA or Voltage Controlled Amplifier (or Attenuator) is used. There are many types of Voltage Control, 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! Since the VCA's really have no signature of its own, this compressor has very accurate, low noise, low distortion A part of the audio signal is rectified and smoothed to produce a suitable control voltage for the VCA 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 compresso