AUDIFIED U73B Compressor User Manual

: March 24, 2024
: AUDIFIED

Table of Contents

Introduction
Working with U73b Compressor
Technical info
Conclusion
Documents / Resources

U73B COMPRESSOR
User Manual
Version 3.1.0

Webpage:audiﬁed.com
Support:audiﬁed.zendesk.com

Introduction

Dear Musician,
Thank you for purchasing the Audiﬁed U73b Compressor eﬀect. This plug-in eﬀect is an emulation of a unique old German broadcast compressor/limiter U73b which was often used for mastering between 1960 and 1980. It is an all-tube vary-mu compressor/limiter with adjustable release time option.
We kept the circuit exactly as it was originally designed and only added an input and output gain before and immediately after the compressor circuit to assist with proper adjustment of the compression. The plug-in eﬀect is also equipped with a VU meter and selectable side-chaining.
We’ve also added a Compression amount parameter since version 3.0.0 allowing users to adjust the compression eﬀect of the vary-mu stage while keeping the rest of the simulation as it is, including its saturation and color behavior.

Software Installation
Get the recent version of the plug-in from your user account on our website:
Webpage:audiﬁed.com/account/downloads

Windows: The downloaded ﬁle is packed, unzip it. Run the installer and follow the on-screen instructions. You can select the destination path and the installed plug-in format during the process.
Mac: Mount the downloaded disk image and run the installer. You can select the installed plug-in format by clicking the Customize button. Plug-ins are installed in the standard locations.

Product activation
Starting with version 3.1.0, you will automatically create an account via checkout if you are a ﬁrst-time buyer. You can also sign in to your account anytime on our site audiﬁed.com via the Account icon in the right corner to access your Account dashboard.
Upon completing the purchase, you will receive an automatic email containing your serial numbers and the download link for your purchased products.
When you ﬁrst launch the plugin, you will be asked to enter the serial number, or you can use the product for a limited time as a trial.

Software Uninstallation

Windows: Navigate to the U73b Compressor program folder in the Start menu and run the uninstaller.
Mac: Open the provided disk image and run the uninstaller.

Opening the plug-in
AUDIFIED U73b Compressor works in all major digital audio workstations (recording applications) as a plug-in.
To open the plug-in, locate the plug-in selection (usually a hierarchic menu). U73b Compressor is listed in the Dynamics group or in the AUDIFIED group when the manufacturer sorting is oﬀered.

Working with U73b Compressor

Control overview
The interface has the following parts:

Power and calibration module.
Compressor module.
Level control module.
Menu bar area.

Power and calibration module
(On/Oﬀ) switch
Toggles between the processing state and the bypassed state
Calibration
The software model works with real voltages, the same as in the circuit of the original device, related to the dBu scale, but the digital signal processing in the DAWs works with the digital full scale known as dBFS.
We have therefore added a calibration parameter to relate the digital scale (dBFS) with the analog scale (dBu) and it is intended that you set the calibration to work in the proper operational range of the compressor eﬀect. Be careful when working with this parameter. We suggest to set this parameter to the headroom you use in your DAW recordings or headroom of your audio interface.
The default setting is –9 dB and it is loaded every time you load the plug-in. However, the calibration value is overwritten by the value from DAW project (when the calibration is changed explicitly and saved with the project). The default value can be changed in the Settings menu (please refer to the section “Services menu” of this manual for more details).
Compressor module
Circuit emulation of the U73b compressor.
Compressor/Limiter switch
The upper U73b knob switches between the Compressor mode, Bypass and Limiter mode.
The compressor mode has a lower threshold setting and very gentle increasing ratio, in opposite, the limiter mode provides a higher threshold setting with higher ratio but still with a smooth knee.
Release time
The ﬁrst three positions oﬀer ﬁxed release time, the other three positions marked with red labels provide adjustable release time dependent on program content.
Compression amount
Standard dry/wet mix over this plug-in would be complicated as far as the device simulation brings phase distortion the same way as the original device. To give user the ability to adjust the compression amount of vary-mu stage without need to mix dry and wet path of the whole processing, Compression amount parameter was added. It aﬀects the amount of gain reduction caused by vary-mu stage without aﬀecting other stages simulation.
Level control module
Input and output gains, metering.
Input gain
Adjusts the input gain before the compressor/limiter circuit.
Output gain
Adjusts the output gain after the compressor/limiter circuit. This parameter can be adjusted automatically when the “Auto output” switch is on. In this case, the output gain is adjusted automatically to keep approximately the same loudness when the input gain parameter is changed.
Meters switch
Switch the meter to show the input or output signal level or the amount of the gain reduction.

Display area
High Pass Filter
There is a high-pass ﬁlter connected in the circuit in the compressor mode with around 100 Hz cut-oﬀ frequency and 6dB/octave slope. Although this ﬁlter helps to create the unique sound of the U73b compressor, the bass roll-oﬀ might not be suitable for all instruments when mixing, or for all genres when U73b is used for mastering. We have added an extra control to switch this ﬁlter oﬀ. In the limiter mode, this ﬁlter is permanently turned oﬀ regardless of the parameter setting.
Key Input
Selects the signal source used for controlling the gain reduction.
Click to the display item “Key Input” to set the following modes:

Individual – each of the stereo channels is controlled by itself.
Left – both stereo channels are controlled by the left channel input.
Right – both stereo channels are controlled by the right channel input.
Left+Right – both stereo channels are controlled by the sum of left and right channel inputs.
External Sidechain – select this option to control the compression of an audio signal in the given track with an audio signal from another track. This can be used, for example, to create a “ducking” eﬀect or to control the compression of a bass guitar with a kick drum recorded in another track. The external track can be both mono and stereo (stereo not supported by the AAX format). In the case of the stereo external side chain, the left external side chain channel controls the compression of the left compressor channel and similarly the right external side chain channel controls the compression of the right compressor channel. To enable this feature, the DAW must be set for side chaining and must support the side chaining, otherwise this option is disabled. When the DAW side chaining is disabled during plug-in life, the external side chain is switched to the standard plug-in input. Please refer to the user manual of your DAW to set up the side chaining in your DAW.

Preset management
Presets can be loaded and saved on the right side of the menu bar area.

Browse presets with the left and right arrows.
The Load button oﬀers a selection from a preset list, structured in several submenus.
The Store button opens a menu allowing users to save or delete user presets.

Artist presets
The U73b Compressor eﬀect was developed in cooperation with musicians and producers Boris Carloﬀ and Bjorn Thorsrud. Their artist presets are marked BC or BT.

Services menu
A click to Audiﬁed logo opens the Services menu. Services menu allows access to:

user manual,
product updates,
feedback form on the Audiﬁed web,
support,
Audiﬁed website,
product version and other info.

Utility menu
Clicking the wrench symbol opens the utility menu. You can easily copy the state of one plugin instance to the other instance using Copy and Paste functionality. There are also several U73b speciﬁc controls:

Set Calibration As Default
The calibration value set in the opened instance of U73b may be used in all instances, opened in any host or any project. Click this menu item and the current calibration value will be saved as default and will be used when opening other U73bs.
Oversampling
When this setting is turned on, the internal plug-in processing runs at a higher sample rate than set in the DAW. This helps to reduce the aliasing distortion which is always produced by the nonlinear eﬀect processing and improves the processing of high frequencies. However, the cost of more accurate signal processing is a higher CPU utilization. Tip: turn on this option for the ﬁnal render of your project and turn oﬀ when mixing the project.

Technical info

Speciﬁcation

AAX, AU, VST3,
macOS, Windows plug-ins.

Requirements

macOS 10.11 and newer (64bit format delivered),
Windows 7 and newer (64bit format delivered),
150 MB of disk space required.

Conclusion

We are conﬁdent that you can now work with U73b Compressor. However, if anything seems unclear or you need assistance, feel free to contact us.
Support:audiﬁed.zendesk.com

Thanks for using AUDIFIED products.