EVENTIDE OMNI PRESSOR COMPRESSOR PLUG IN User Guide

User Guide

Welcome

part 1

1.1 About This Product

Thank you for your purchase of the Eventide Omnipressor® plug-in. The product recreated in this plug-in was among the first introduced by Eventide – and among the world’s
first commercially available professional recording products. For over 40 years, innovative products like these have made Eventide an industry leader, and we are extremely proud that they continue to be in demand today. We’ll get into more depth on the product soon but, before you forget, please take a few minutes to register online. This helps
us keep you informed of any important software updates and any special offers that may only be available to registered users.

Omnipressor

part 2

Production Dates: 1971 – 1984
Originally described as a ”professional-quality dynamic modifier”, the Omnipressor® rapidly became a very popular studio dynamics piece. Its unique Function knob allowed
the engineer to move from Noise Gate effects through dynamic reversal – an effect that reverses a sound’s envelope making loud sounds quiet, and quiet sounds louder. This control, combined with unique gain and attenuation controls, lets you produce extremely aggressive dynamics with a very little tweaking. A cymbal, for example, can be made to sound ”reversed” by setting a fast Attack and setting Function near its clockwise limit. The diagram below illustrates the wide-ranging Function control.

The controls are divided into three main sections: Main Panel, Expansion Panel, and the Preset Bar.

2.1 Main Panel

Input Threshold| Sets the gain crossover point. For example, when the system is in Compression mode, an input signal below the threshold will have its amplitude increased and signals above the threshold will have their amplitude reduced.
---|---
Line In/Out| Bypasses the processing on the Omnipressor®. The meters will continue to operate as normal but the signal will not be altered.
Attack Time| Determines the time in which the system responds to a change in input level. Assuming a 10 dB step increment in input level, the attack time is numerically equal to the time required for the level detector to reach its final state with respect to the new input level.
Bass Cut/Norm| Determines the frequency response of the level detector circuit. Set to NORMAL to match the frequency response to the gain control section. Set to BASS CUT to attenuate bass signals and reduce their effect on the overall compression/expansion operations.
Release Time| Determines the time in which the system responds to a decrease in input level. Assuming a 10 dB step increment in input level, the attack time is numerically equal to the time required for the level detector to reach its final state with respect to the new input level.
Meter Function| Allows you to select meter monitoring of Input, relative Gain, or Output. These functions control only the meter display – they have no effect on signal processing. All level readings are in dBfs.
Function| This is the main Omnipressor® control. When set fully counterclockwise, gain varies sharply from full attenuation to maximum gain as the input threshold is exceeded. As the control is rotated clockwise, this action becomes less sharp until the gain varies only a few dB from no input to full input.
At the knob’s center point, the gain is constant, regardless of the input level. As the knob is turned clockwise, gain begins decreasing with increasing input level. More rotation produces substantial compression until the point of infinite compression is reached and the gain decreases 1 dB for each dB of signal increase, thus keeping the output level constant regardless of input. Rotation past this point produces dynamic reversal, in which a high-level input produces a lower output than does a low-level input. Full clockwise rotation results in full output attenuation
above the Input Threshold.
Two LEDs alert you to the gain state of the Omnipressor®. A green Atten Led illuminates to indicate that the Omnipressor is in gain reduction mode. A red Gain Led illuminates in gain increase mode. The relative brightness of the LEDs indicates the amount of gain reduction or increase. Operation of these LEDs is instantaneous, so that peak limiting is indicated even when the meter has insufficient time to respond.
Output/Cal| These switches allow you to increase the output level of the Omnipressor® without affecting compression ratios or other operating parameters. This is useful, for example, when the unit is being used in extreme modes of compression or dynamic reversal, and the input signal is large enough to cause large amounts of consistent gain reduction. In such cases, you can select to increase the gain of the output stage by selecting +10dB,
+20 dB, or both for 30 dB of gain. This control does not alter the gain of the dry signal. 1

1Older versions of the plugin featured Input Calibration switches as well. These switches allowed the user to attenuate the input signal by 0, -10, -20, or -30 dB. The functionality of these switches has been superseded by the Input Gain control, which allows a continuous range of values from -48 dB to +12 dB, but the old controls will continue to function as before to ensure backward compatibility. They remain accessible via automation or generic plug- in views.

Atten Limit| Limits the maximum attenuation of the Omnipressor® from 30 dB to approximately 1 dB. This control overrides the action of Function.
---|---
Gain Limit| Limits the maximum gain of the Omnipressor® from 30 dB to approximately 1 dB. This control overrides the action of Function.

2.2 Expansion Panel

Input Gain| Adjusts the gain of the incoming signal to the Omnipressor®.
This control does not alter the gain of the dry signal.
---|---
Sidechain Input| Allows the Omnipressor®’s level detect to be driven by another audio source.
Mix| Adjusts the dry-wet mix. At 100%, the output will only be the processed signal. Use values of less than 100% for parallel compression.
Output Gain| Adjusts the output gain of the processed signal. Like Input Gain, this control does not alter the gain of the dry signal.

2.3 Preset Bar

Located at the top of the Omnipressor® Plug-In, the Preset Bar lets you load and save presets, along with several other features.
When Omnipressor® is installed, a library of settings is placed into the **