Foreword by John G. Petersen

After several years of consideration, we decided that the time had come to introduce a plugin of our TUBE-TECH CL 1B.

The development of the plugin was initialized in November 2006, as a cooperation between Lydkraft, Softube and TC Electronic. Hearing the result, we found that Softube was able to reach the difficult goal of making a plugin of the CL 1B which came extremely close to the original sound and gave the user all the characteristics of the hardware. After very serious testing of the software, the plugin was released late 2007.

To take this project one major step further, we decided in early spring 2009 to release a VST/AU/RTAS version of the plugin, and once again placed the developing task in the hands of Softube.

We are very impressed by the skills of these young guys from Sweden and we feel excited that the quality of the CL 1B is now available for all workstation users.

We hope you will enjoy the excellence of the TUBE- TECH CL 1B plugin.

Yours sincerely,

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About the CL 1B

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The hardware CL 1B differs from many other compressors in that the gainreduction element is made from a nonsemiconductor component, which in itself has a very low harmonic distortion and none of the nonlinearity problems involved when using most semiconductor elements. All parts of these equally important design choices have of course been painstakingly modeled when creating the CL 1B plugin.

Another thing that is special about the CL 1B is the Attack/Release Select switch which allows the user to switch between a manual and a fixed attack/release setting, but also makes it possible for the user to combine both the fixed and manual settings. This gives a feature not normally obtained in other compressors: In the combined mode the attack and release controls makes it possible to obtain complex program dependent releasetime slopes where a fast peak results in a fast release and vice versa.

 

User Interface

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  1. Gain
  2. Ratio
  3. Threshold
  4. Meter select
  5. VU meter
  6. Attack time
  7. Release time
  8. Attack/Release select
  9. Sidechain bus select

Gain: The Gain control is used to “make up” for the gain loss, which takes place when the unit is compressing. It is placed after the gainreduction circuit and therefore has no influence on the threshold setting. The Gain control is continuously variable from off to +30 dB.

Ratio: The Ratio control varies the ratio by which the input signal is compressed. If the ratio selected is 2:1, and the input signal increases 10 dB, the output signal is only increased by 5 dB. The Ratio control is continuously variable from 2:1 to 10:1.

Threshold: The threshold is the point where the compressor begins its action. It is defined as the point where the gain is reduced by 1 dB. The Threshold control is continuously variable from +20 dB to –40 dB.

Meter Select: Select what the VU meter should display:

INPUT: The meter shows the input level.

COMPRESSION: The VU meter is showing the gain reduction.

OUTPUT: The meter shows the output level.

Please note that it does not show peak or true RMS, it is a VU meter and behaves just like the original unit.

The meter and the plugin is calibrated so that a sine wave showing 0 VU at the output corresponds to a –18 dBFS output signal. Correspondingly, a 18 dBFS sine at the input will show 0 VU if the meter is set at showing the input signal.

 

Attack Time: The Attack control chooses how fast/slow the compressor responds to an increase in the input signal. It is continuously variable from 0.5 to 300 milliseconds.

Release Time: The Release control sets how fast/slow the compressor responds to a decrease in the input signal. It is continuously variable from 0.05 to 10 seconds.

Attack/Release Select: This switch selects how the compressor reacts to an increase (attack) or a decrease (release) of the input signal.

There are three settings of this switch:

FIXED: Attack time: 1 millisecond Release time: 50 milliseconds.

MANUAL: Attack time: From 0.5 to 300 milliseconds Release time: From 0.05 seconds to 10 seconds.

FIX./MAN: This setting combines the release times of fixed and manual mode. The attack time is as it is in the fixed mode.

The FIX./MAN. mode always has a fast attack, but it is possible to obtain a release time that depends on the input signal, for example get a fast release when the peak disappears, then superseded shortly thereafter by the release time selected by the Release control.

The time the peak disappears to the point where the selected Release time takes over, is dependent upon the setting of the Attack control. That is, the Attack control changes function from a pure attack control to a control of the delayed release with the same time range.

Turn the Attack control clockwise to increase the time before the Release control takes over. Decrease the Attack control to shorten the time before the Release control takes over.

This function is valid only if the time of the peak is shorter than the setting of the Attack control. If the peak of the program is longer, or if the Attack control is set at its minimum position, it will respond just as in the MANUAL mode.

The FIX./MAN. mode acts as an automatic release function with a constant fast attack time and fast release time for short peaks and longer release times for longer peaks. This settings is mainly intended for use on program material (overall compression).

Sidechain Bus Select: This knob has two settings:

INTERNAL: Normal mode. The compression depends on the same material as is being compressed.

EXTERNAL: Use an external side chain (if your hosts supports it) to control the gain reduction.

In many plugin formats, such as RTAS, VST3 and AU, it is possible to use an external signal as input to the detector. This is very common if you for instance want to compress a bass line using the bass drum as the trigger to the compressor. In that case, the bass line will be compressed whenever the bass drum is hit.

Monitor the Gain Reduction VU Meter when you set the threshold, since the Input VU Meter will show the original input signal. Just work with the Threshold knob until you get enough gain reduction.

Even if an external side chain signal is present, you will have to activate the external side chain by setting the Sidechain Bus Select to EXTERNAL.

 

Suggested Applications

Here you will find suggestions on various applications of the Tube- Tech CL 1B compressor plugin. They are given as a convenient guide that enables you to familiarize yourself with the different aspects of using the compressor. We have not mentioned specific settings of the Gain and Threshold as they are dependent on the input levels. Instead we have specified how much compression in dB we feel is needed for the various examples.

These examples were taken from the CL 1B hardware manual, and are of course just as valid for the plug-in as for the real unit.

Overall Compression (Final Mix)

Compression needed: 3-4 dB

Attack/Release Select: FIX./MAN.

Attack: 2 o’clock

Release: 10 o’clock

Ratio: 9 o’clock

Standard Compression (Bass, Piano, Guitar, Keys and Vocals)

Compression needed: 4- 5 dB

Attack/Release Select: MANUAL

Attack: 2 o’clock

Release: 10 o’clock

Ratio: 10-2 o’clock

Heavy Compression on Instruments (Line Guitar and Piano)

Compression needed: 10 dB

Attack/Release Select: MANUAL

Attack: 7 o’clock

Release: 1 o’clock

Ratio: 3 o’clock

Compression of Drums (Snare and Bass Drum)

Compression needed: 2- 3 dB

Attack/Release Select: FIXED

Attack: –

Release: –

Ratio: 9-12 o’clock

 

Mono and Stereo Operation

In stereo mode, the gain reduction of the left and right channel is always linked, in order to reduce stereo image shifting. The gain reduction used will be calculated from a combination of the two channels, just as if two hardware CL 1B had been linked together using a sidechain bus.

 

CL 1B Mk II

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Mk II version is enhanced with features not found in the original hardware:

Sidechain Low Cut: Filters the low end from the sidechain signal. Please note that the main signal path is not filtered.

Parallel compression: Sets the amount of parallel processing. For more information on Parallel compression, please check Bob Katz’ article.

 

Extended Features

A whole range of added control can be accessed with Extended Features. Please see the separate "Extended Features" manual for more information.

 

Credits

Arvid Rosén – Modeling
Oscar Öberg – Modeling and DSP programming
Torsten Gatu – Framework and DSP programming
Niklas Odelholm – GUI and framework programming
Ulf Ekelöf – 3D rendering
Original hardware was designed by John G. Petersen at Lydkraft ApS

 

Credits – Mk II Version

Paul Shyrinskykh – Product management
Kim Larsson – DSP and framework programming
Björn Rödseth, Kim Larsson, Patrik Holmström – Framework programming
Niklas Odelholm – Graphic design
Ulf Ekelöf – 3D rendering
Daniel Delviken – Marketing
Maxus Widarson – Quality assurance
Igor Miná – User manual layout

TUBE-TECH IS A REGISTERED TRADEMARK OF LYDKRAFT ApS, DENMARK. ALL SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE. ALL RIGHTS RESERVED.