Blue Cat's Destructor User Manual

Blue Cat's Destructor - Distortion and Amp Sim Plug-In (VST, AU, AAX, VST3, RTAS, DX)
"The distortion and amp sims factory that actually goes to 11"
Mac OS X 10.5+32/64-bit Universal BinaryWindows Vista or newerWindows x64 (64-bit)VSTVST3AAX64-bit AAXAudio UnitRTASDirectX



Blue Cat's Destructor is a powerful distortion and amp sim modeling tool capable of simulating any kind of distortion: from harsh digital destruction to smooth compression or guitar amp simulation (works for clean tones too!), and most importantly, yours!

It is delivered with hundreds of presets and predefined models, either inspired by existing gear (guitar & bass amps or cabinets, compressors, pedals, tape machines...) or created by our destructive minds.

But the plug-in is not limited to these predefined models: all parameters of existing presets are fully editable, which gives you access to an unlimited number of distortion simulations - no need to purchase extra presets or amp models to build your custom tone.

Based on a perceptual model rather than on electronic designs or impulse responses, the signal chain is reduced to its bare minimum, simplifying the process of tweaking the tone and making it fit into the mix.

Thanks to its exclusive adaptive shaper, it is reactive to the playing of instrumentists, providing a very natural feeling, similar to analog gear.

To make the look and feel of the plug-in fit with your favorites tones, it is bundled with more than 1600 visual styles that can be selected separately for each module.

It is also possible to import reference curves measured with Blue Cat's FreqAnalyst Multi to quickly match existing tones.

The plug-in can be loaded into Blue Cat's PatchWork to be used as a standalone application, where it can be combined with other effects to build your tone.

For frequency-selective or multiband distortion, the plug-in can be used in combination with Blue Cat's MB-7 Mixer.

Blue Cat's Destructor - Distortion and Amp Sim Plug-In (VST, AU, AAX, VST3, RTAS, DX) Blue Cat's Destructor - Distortion and Amp Sim Plug-In (VST, AU, AAX, VST3, RTAS, DX) Blue Cat's Destructor - Distortion and Amp Sim Plug-In (VST, AU, AAX, VST3, RTAS, DX) Blue Cat's Destructor - Distortion and Amp Sim Plug-In (VST, AU, AAX, VST3, RTAS, DX)

Typical applications: Distortion modeling, guitar amp simulation, non-linear tone shaping channel strip, overdrive, bit crushing, analog compression, hard & soft clipping, coloring, tape saturation, Lo-fi, fuzz, digital noise, aliasing, filter effects.

Credits: this plug-in includes several factory presets created by "Sink" and Hans Van Even.


Main Features

  • Powerful distortion and amp modeling tool.
  • Simulate any kind of distortion: analog or digital, guitar and bass amps, saturation, clipping, compression, bit crushing...
  • Works for "clean" sounds too.
  • Get started with several hundreds of fully editable presets, inspired by real gear.
  • More than 1600 visual styles to customize the user experience.
  • Control the dynamics with the input gate and compressor.
  • Control the tone with the pre and post filters.
  • Exclusive shape dynamics control: adapt the tone to the dynamics of the signal.
  • Use the internal or external side chain to trigger the distortion.
  • Protect your ears with the output brickwall limiter.
  • Comprehensive visual feedback: real time spectrum analysis, dynamic distortion curve display with embedded signal histograms.
  • Load reference curves for tone matching.
  • No latency.

Blue Cat Audio Standards:

  • Available as: Mac-AAX, Mac-AU, Mac-RTAS, Mac-VST, Mac-VST3, Win-AAX, Win-DX, Win-RTAS, Win-VST, Win-VST3, Win x64-AAX, Win x64-DX, Win x64-VST, Win x64-VST3.
  • Native DSP code for optimal performance.
  • Full MIDI control and automation support with silent, zipper-free parameters update, advanced response control and MIDI Learn.
  • No CPU load on idle: when the plug-in is fed with silence, the processing smoothly shuts down, to optimize the CPU usage of your Digital Audio Workstation.
  • Skinnable and customizable user interface with transparency management.
  • Smooth Bypass: activate/deactivate the plug-in with absolutely no noise.
  • Undo/Redo.
  • Full featured integrated presets manager.
  • Copy/paste the state of the plug-in between instances using the system clipboard.
  • Any sample rate supported.

System Requirements


  • An SSE2-enabled processor (Pentium 4 or newer).
  • Microsoft Windows Vista, Windows 7, 8 or 10.
  • Any DirectX / VST / RTAS / AAX compatible host software (32 or 64 bit).

Mac OS X

  • An Intel processor.
  • Mac OS Sierra (10.12), Mac OS X El Capitan (10.11), Mac OS X Yosemite (10.10), Mavericks (10.9), Mountain Lion (10.8), Lion (10.7) .
  • Any VST / Audio Unit (32/64-bit) / RTAS / AAX compatible application.

For more information about supported platforms, see our FAQ.

Demo Limitations

  • 5 instances of the plug-in allowed per session.
  • The effect is bypassed for half a second every minute.


The plug-ins versions cannot be run standalone: they require a host application (see the System Requirements chapter for more information). Depending on which host application you use, you might need to install the plug-ins in different locations.

Before installing one of the plug-in versions, you should close all your host applications.



All versions of the plug-in provide an installation program. Follow the steps of the wizard to install the software on your machine. During the installation you will be asked where you want the software to be installed. For the VST version, you should install the plug-in inside the VST plug-ins folder used by your host application(s). The default path set in the installer should work for most applications, but you should check your host software documentation to know where it looks for VST plug-ins. For other plug-in types, you should just use the standard path.

Some applications will not automatically rescan the new plug-ins, so you might have to force a refresh of the plug-ins list.


When a new version of the software is released, just launch the new installer: it will update the current installation.


To uninstall the software, simply launch the "Uninstall" program that is available in the start menu or in the configuration panel. It will take care of removing all files from your computer.



On Mac the plug-ins are available as drive images. After download, double click on the file to open it. You can then drag and drop the file(s) to the shortcut that is provided within the image. It will install the software for all users on the machine.

In case you do not have admin rights on your Mac or if you want to install the software to another directory, just copy the files to the appropriate location. If required, more information is available in the README.txt file that is included in the package.


When a new version of the software is released, open the new image and copy the files over the previous ones. The new version will replace the older one.


To uninstall the software, simply remove the component(s) from the folder where you have copied them during install (move them to the trash).

If you want to completely remove all settings and configuration files, you can also remove these additional directories that may have been created on your computer:

  • ~/Library/Preferences/Blue Cat Audio/[Plug-in name and TYPE], where TYPE is VST, AU, RTAS or AAX: global preferences.
  • ~/Library/Preferences/Blue Cat Audio/[Plug-in name]: license information
  • ~/Documents/Blue Cat Audio/[Plug-in name]: user data, such as presets, additional skins and user-created plug-in data.

Please be aware that these directories may contain user data that you have created. Remove these directories only if you do not want to reuse this data later.

First Launch

Blue Cat Audio plug-ins cannot be run standalone, they require a host application (see the System Requirements chapter for more information). Some host applications will require you to scan the plug-ins before they are available in the application.

If the plug-in is not available in the application, please check that it has been installed in the appropriate directory (with no host application running), and that the host application has scanned it.

Using Blue Cat's Destructor


Overview and Signal Flow

Blue Cat's Destructor is based on a simple scheme that replicates the behavior of most systems that generate distortion in the real world:

  • Pre-filtering or pre-emphasis.
  • Non-linear distortion that generates overtones.
  • Post-filtering.

The plug-in also includes a gate and a compressor at the input to control noise and peaks before applying distortion, as well as an output brickwall limiter to avoid overshoots:

The purpose of the plug-in is to help you build your own distortion tone, either using existing module presets or creating it from scratch.

About Distortion

Distortion is the alteration of the original shape of a waveform, resulting in the production of extra overtones that enriches the sound.

To perform this step, Blue Cat's Destructor employs a special dynamic waveshaping technique, using a shaping curve that may vary over time, based on the incoming signal:

The green curve above shows how incoming values are transformed into an output signal. As you can see above, the shape of the reference sine wave (blue curve) is transformed into a more-squared version (red curve) by the transfer curve.

It results in the creation of harmonics in the frequency domain, as shown by the orange curve below (compared to the blue spectrum of the original sine wave):

The number of harmonics and their frequencies depend on the shape of the transfer function (more on this later).

About Filtering

Post Filter

As seen in the previously, distortion will generate many high order harmonics, which usually sounds quite harsh. So you will naturally want to filter them to control their intensity, using post-filtering:

In the real world, such filtering happens at many stages. For example, when recording a guitar amp, the tubes, cabinet and microphone all add their own filtering, with more or less control over it. With Blue Cat's Destructor, you can precisely define how much of each frequency you want to hear in the end. All editing can happen in a single place.

Pre Filter

So what is pre-filtering for, then? Also called pre-emphasis, pre-filtering lets you choose the impact of frequencies on the distortion: frequencies that are attenuated by the post filter will generate less harmonics that the frequencies that are emphasized.

For example, if the lower end of the spectrum is emphasized, the destruction step will generate many harmonics in the mid range (sometimes masking the original sound), whereas if treble is boosted, most harmonics will reside in the high end of the spectrum, enriching the original sound with less masking. (This is of course dependent on the content of the original sound)

A common practice is to boost some areas of the spectrum with the pre-filter and then attenuate them with the post filter (or vice versa), to produce a more balanced spectrum.

Shape Dynamics

As mentioned earlier, the shaping curve in Blue Cat's Destructor is dynamic, and can be controlled by the audio signal, using a dedicated envelope follower.

In many cases, this is what gives a natural feeling to the distortion produced by the plug-in, as it will react to changes in the dynamics of the incoming signal.

It is also possible to feed this detector with an external side chain signal, to trigger the distortion with another track for creative purposes. Just give it a try with a kick drum as a side chain to distort a synth or guitar track: it will give you the idea!

Using Modules

The pre and post filters as well as the destruction processor are built as independent modules. All of them offer a wide variety of presets that can be used as predefined models to create your own tone.

As described in details later in the manual, all three modules have an "easy" and an "edit" mode. The easy mode gives access to only a few parameters of the underlying model, and the edit mode is a more advanced view with "full access" to the module. When building a tone, you should usually start in easy mode, loading existing presets for and changing "easy" parameters. You can then enter the edit mode for fine adjustments, or to create your own distortion model.

It is also possible (and recommended) to create your own presets with your favorite settings for each module, to reuse and combine them later. Given the number of parameters available, it is in often much faster to reuse such presets and only touch the controls offered by in "easy mode" to adapt the tone to specific situations.

Getting Started

That's enough theory for now... Let's get started! To become familiar with the plug-in, you can first browse and test the global presets to hear what the plug-in can do. Enter the edit mode for presets that you like, to have a better understanding of the underlying models.

You can also try to switch between different module presets to hear the difference, and check how they have been built with the edit mode. You can also use locks to keep the settings of a section you are satisfied with, while browsing presets to change other settings.

Once you have a good understanding of the role of each module and its influence on the tone, you can create your own models, based on existing presets or from scratch.

The reference curve import feature can also be helpful to build your filters, especially if you want to mimic existing gear that you can measure.

The User Interface

Note: The main toolbar, menus and basic features available with all our plug-ins are detailed in the Blue Cat Audio Plug-ins Basics section.


The user interface mostly follows the signal flow described in the previous chapter from top to bottom and from left to right:

Click here for full size screenshot

Main Components

  1. The main toolbar, with from left to right: the bypass button, in and out gain controls, the main toolbar buttons, the presets manager and text display LCD.
  2. The input gate controls.
  3. The input compressor controls.
  4. The pre-filter module, in "easy" mode.
  5. The destruction module, in "easy" mode.
  6. The post-filter module, in "easy" mode.
  7. The brickwall limiter switch, to enable or disable the limiter. You will usually want to keep it enabled to protect the output of the plug-in. in this case you should try to adjust the output gain so that the limiter is not triggered, unless you explicitly want its pumping effect.


Level meters are available to monitor the audio level at each stage of the processor. Please note that no clipping happens between modules, so it is not a necessity to keep levels below 0 dB. It is however a good practice, in order to precisely control the dynamics and the distortion stages.

The reverse blue meter next to the "PRE" level meter displays the gain reduction performed by the gate and compressor, while the same meter in the "OUT" section displays the activity of the output brickwall limiter.

Features common to main modules

The three main modules have a similar user interface, with from left to right:

  • The power button to enable/disable the module (clicking on the title works too).
  • The module presets area: left and right arrows can be used to switch presets for the module, while clicking on the preset title opens the following menu to manage the presets:
  • The level meter displays the audio level at the output of the module.
  • The arrow button opens a menu to select a GUI style from the 1400 available. The style will be applied to the "easy" view of the module, as shown in the following example:
  • The "+" button lets you enlarge or reduce ("-") the current view. For the destruction module in edit mode, it will also show or hide the advanced settings (dynamics, oversampling and phase distortion).
  • The "e" button switches the module between easy and edit modes.

Gate and Compressor

The gate and compressor placed at the input of the plug-in offer standard controls:

  • Attack/Release control how fast the gate or compressor reacts to level increase/decrease. They can be set to 0 to follow the signal instead of its level, causing extra distortion.
  • Threshold is the level at which the gate or compressor starts being active. The gate closes below the threshold, whereas the compressor compresses above the threshold.
  • Ratio controls the amount of compression/gating: increase the value to get more.
  • Makeup Gain is the post-compressor gain, usually used to compensate the gain reduction of the compressor.

To disable the gate or the compressor, just set the ratio to 1 (or right click with the mouse on the ratio control).

Pre and Post Filters

Pre and post filters have the exact same user interface and controls. settings can actually be exchanged between the two using copy/paste, and their presets are compatible.

Easy Mode

In this mode, the simplified controls are straightforward: Bass, Mid, Treble, Tone (if active) and Gain.

The knobs of the easy view control the gain (frequency for TONE) of some of the filters which characteristics are set in the edit view. So the frequencies, bandwidth and ranges of these knobs may vary.

Edit Mode

Behind the scenes, several filters are combined to build a custom frequency response and can be edited in details in this mode:

  • A low cut filter with variable slope, to remove lower frequencies.
  • A low shelf filter, corresponding to the BASS control of the easy view.
  • Three peak filters. The pink filter corresponds to the MID control of the easy view.
  • A high shelf filter, corresponding to the TREBLE control of the easy view.
  • A high cut filter with variable slope, to remove the higher frequencies. If the slope is not 0 (filter inactive), the TONE control will be available in the easy view.
  • A Comb filter to create "holes" in the spectrum.

The additional slider on the right controls the gain of the module (same as the GAIN control of the easy view).

When a filter is active, its characteristics are displayed in the main LCD screen at the top of the plug-in. Also. knobs will appear at the bottom of the edit view for fine tuning:

Additional controls at the bottom right give you access to the following features, from left to right:

  • Select the dB range for the edit view and for the gain controls in the easy view: this setting affects both views so that the range of the knobs can be limited from the edit mode.
  • Activate spectrum analysis and select spectrum display type. When "spectrogram" is selected, an extra knob appears to let you adjust the contrast.
  • Show/hide the reference curve (pink curve in the above screenshot). The reference curve can be used to match external filters measured with Blue Cat's FreqAnalyst Multi or copied from the filter module.
  • Open the reference curve menu to load reference curves or paste them from the FreqAnalyst Multi plug-in. The current filter curve can also be copied or saved similarly:

The Destruction Module - Easy Mode

The destruction module is the core distortion generator of the plug-in. The easy view display very simple controls over the distortion, which exact behavior depends on the other settings of the module:

  • Drive: more drive means more distortion. However in some cases (when the destruction curve is setup in particular ways), it can control the amount of compression instead.
  • Dynamics: the more dynamics, the more the destruction will vary depending on the audio signal. When increasing the drive parameter, you may want to decrease the dynamics parameter.
  • Mix: controls how much non-distorted (dry) signal is blended with distorted signal (wet). 100% if for full wet signal, whereas 0% will completely bypass the destruction stage.
  • Gain: the gain applied at the output of the destruction module, to compensate gain changes due to distortion.

The Destruction Module - Basic Editing

When switching to edit mode, the destruction curve as well as decimation settings can now be edited:

The destruction curve (also called "Shaper") has its own preset manager (displayed below the graph), so it is possible to save the settings or recall destruction shapes instantly.

Before getting into the edition of the curve, you can see that several curves are displayed:

  • The white curve ("user curve") is the curve specified by the user-selected points as well as the "Smooth", "Symmetric" settings available on the right of the LCD screen.
  • The green curve ("computed curve") is the actual curve currently applied to the signal, using additional settings (drive, shape mix, rectify) as well as the dynamics response of the signal, if used.
  • The blue curve is a reference sine wave (pure tone waveform).
  • The pink curve is the result of the destruction shaper applied to the sine wave, to help you understand what the curve actually does.

Editing the Shaper Curve

The basic shape of the curve can be set with three points (the white dots and the arrow on the right).

Additional Curve Controls

Additional controls affect the shape of the distortion curve. You can experiment with them to see the impact on the curve:

  • Smooth: performs smoothing between points. Reduces harshness of the distortion.
  • Rectify: performs rectification on the curve for asymmetric distortion (and more).
  • Bit Depth: simulates bit reduction by quantifying the distortion curve.
  • Shape Mix: acts like a dry/wet knob but applied to the destruction curve.

Visual Feedback

The shaper curve display provides additional visual feedback about the processed signal: the input (blue) and output (pink) histograms show the distribution of the audio signals at the input and output of the shaper. They are also reported on the green curve using yellow dots to highlight the current activity of the curve and its impact on the signal.


In addition to the drive, mix and gain settings already seen on the easy view, it is possible to apply sample rate reduction after the shaper stage. This is ideal to produce typical digital Lo-fi effects.

You can choose the amount of antialiasing used during decimation. With antialiasing set to off, decimation will produce additional digital artifacts (aliasing).

The Destruction Module - Advanced Edit

After clicking on the "+" button of the destruction module while in edit mode, additional controls are available:

Shape Dynamics

As mentioned earlier, the destruction curve can become dynamic, adapting to the incoming sound (or another track using side chain). The "Shape Dynamics" section lets you control this behavior.

You choose the source of the signal to be analyzed by the envelope follower with the drop-down box (plug-in input / after the gate, comp or preamp / external side chain). You can then set the attack and release time and shape that define the envelope, and monitor the current measured envelope on the meter on the right.

The two arrows define the threshold (blue) and ceiling (pink) that control the range in which the dynamics control has an effect. If the ceiling is set below the threshold, the dynamics effect is simply reversed.

More details about these parameters can be found in the next chapter.


The non-linear parts of the destruction algorithms can be processed at a higher sample rate (up to 4x upsampling) to avoid digital artifacts. This is particularly useful when using lower sample rates (44.1 or 48 kHz).

Phase Shift

Additional phase shift can be applied to the signal before it hits the destruction curve. You can select here the center frequency and amount of phase shift.


Several locks are available to prevent changes while loading presets: when the lock is active, loading presets will not change the parameters of a locked section. A general UI lock is also available in the toolbar, if you want to keep the same user interface settings (GUI layout, spectrum view options, reference curves) while browsing presets.

Using the Controls

The various elements of the user interface (knobs, sliders, buttons...) are simple and intuitive to operate, but more information about how to interact with them is available in the "Plug-ins Basics" chapter of this manual.


This section describes how to build your tone using the specific controls of each module. An overview of the modules and their controls is available in the previous chapter. A complete list of the parameters exposed by the plug-in is available in the next section.

Getting Started

Explore the Presets

As explained earlier, the best way to get started is to use existing presets first, then modify the tone by switching presets provided for each module. The plug-in contains hundreds of presets and sub presets so that it can be used almost exclusively with presets (and module presets) if you do not wish to get into the details of editing.

Note about levels: since distortion is highly dependent on the input level and the content of the input signal, you may have to adjust the input and output gains of the plug-in when using using presets on your own material.

As a rule of thumb, you should try to make sure that the input level never exceeds 0 dB and that the output brickwall limiter is never triggered (unless its pumping effect is desired).

Tip: adjust Drive and Dynamics. It is not because an existing preset was set for "crunch" that it won't work well when pushing the drive to 11 or reducing it to get a clean sound. Also, feel free to experiment with the "Dynamics" setting: the preset will react very differently depending on the incoming sound and th eway you play.

Editing Presets

If a preset is close to the desired effect but note quite, you can first try to tweak the parameters available in easy mode. It should give you enough control to adjust the tone in most cases.

For finer tuning, you can turn the modules you want to change into edit mode and access the more advanced parameters. Remember that you can save your changes as new presets for each module and reuse them later.

Creating a Sound from Scratch

Once you are familiar with each module and the impact of its parameter on the tone, you may want to create new sounds from scratch.

The exact methodology depends on the type of sounds you are looking for and the instrument to process. In general, you will likely want to start with a post-fiter that (at least) reduces higher frequencies (see the "Lowpass" preset). For guitar sounds, using a cabinet or amp preset for the post-filter will probably be a good choice, since it has a very large impact on the overall sound.

Just remember that all three module have a deep interaction with each other, so any drastic change on one of them may require some more editing on other. For example, boosting frequencies with the pre-filter for emphasis is likely to require some compensation on the post filter.

Using the Destruction Module

The destruction module is the core of the Destructor plug-in. This is where harmonics are generated and what causes the distortion.

Setting Up the Shaper Curve

The first step is to choose the shape of the destruction curve: load a shape preset or edit the curve using the white dots or arrows. Keep in mind that the shape of the curve continues with the same slope beyond 0dB:

This sets the behavior of the Destruction module when fed with signals above 0 db (overshoots).

Note: unlike the dot controls, the arrow sets a point that is not affected by the drive parameter, as shown in the graph below:

dots vs arrow when increasing drive.

Tip: while changing the shape of the curve, you should keep an eye on the reference sine wave to check an audio signal is actually affected.

Shaper Curve & Sound

As a general rule, the more edges in the shaper curve, the more harmonics, and the harsher the distortion. A quick look at the shape of the transformed sine wave in the following examples will give you the idea:

From soft tube saturation to harsh digital distortion

You can use the "smooth" parameter to reduce edges and soften higher order harmonics for a more analog-like sound.

Symmetrical vs Asymmetrical

The plug-in lets you setup symmetrical or asymmetrical distortion in several ways: first, increasing the rectify parameter will produce an asymmetrical curve. Also, in non-symmetric mode, additional points can be specified for the lower part of the shaper:

Asymetric clipping is known to produce mainly even order harmonics, whereas symmetric clipping emphasizes odd harmonics. The difference is subtle but noticeable (especially with post-filter disabled). Try by yourself and check if you can hear the difference.

As an example, tube amplifiers using several stages with rectification are known to be asymmetrical, whereas most designs with transistors or early single stage tube amplifiers are likely to be more symmetrical. However, this is not a general rule (typically, fuzz pedals use transistors to produce highly asymmetrical clipping).

Also, what makes the biggest difference between such types of distortion circuits is not the symmetry of the shape but its dynamics, as explained later in this manual.

The Drive Parameter

Increasing the drive offsets the destruction curve towards the origin as if the input gain was increased, and produces more distortion, without necessarily increasing the peak levels (it depends on the shape of the curve, though):

Drive, more drive, and much mor drive

Tip: a good practice is to setup the shape in such a way that the distortion is barely noticeable when the drive is set to 0, so that you can then use the its entire range efficiently (remember, it goes to 11!).

Adding Dynamics

As mentioned earlier, the dynamics of the destruction shape is what makes the biggest difference between distortion tones, especially for very expressive instruments such as guitars, and even more for small amounts of distortion ("crunch sounds").

If you haven't experimented with shape dynamics yet, you may have noticed at this stage that static distortion can sound flat and tiring in some cases.

Adding dynamics to the destruction process can greatly improve the distortion and the feeling while playing an instrument into the plug-in, simply because it implies a direct interaction between the instrument and the distortion effect.

Very basically, dynamics control is a system that defines how much the curve affects the signal - just like the "Shape Mix" parameter - based on the measured level ("envelope") of the signal.

Shape Dynamics Controls

Shape dynamics is impacted by four categories of parameters, which are similar to what compressors usually offer:

The source: the source selector lets you choose which signal affects the destruction curve. You may want to use the input signal before the compressor and gate if you want finer control from the instrument, or directly at the preamp stage, if you prefer to simulate the dynamics effect of electronic circuits. The external side chain source lets you trigger the distortion from another audio source, and produces very interesting side chain distortion effects.

The range: this is the amount of dynamics applied to the curve. This is the main control to choose how much the curve may change over time, based on the signal envelope coming from the selected source. When it is set to 100%, there will be no distortion at all (straight curve) when the envelope goes below the threshold (or above, if the ceiling is lower than the threshold).

The envelope settings: just like for a compressor, the attack time sets how fast the plug-in reacts to level increases, whereas the release time sets how fast the plug-in will decrease its envelope when the signal level drops. For each of these times, the shape parameter changes the shape of the attack and release curves:

Example: influence of the shape parameter on release

For positive values, the overall time will be increased, because the envelope follower becomes slower and slower. Whereas for negative values, the overall time will be reduced, because the envelope follower gets faster and faster. You can experiment and check the envelope meter on the right to visualize the impact of these parameters.

If you are familiar with our dynamics processing plug-ins, the behavior is very similar.

The threshold ("cold") and ceiling ("hot"): when the envelope meter reaches the ceiling (and beyond), the destruction curve is the same as if no dynamics was applied (100% wet). When the envelope reaches the threshold (and beyond), the distortion is reduced by the amount specified by the range parameter.

The green curve on the graph reflects these changes in real time. The threshold can be set below or above the ceiling, which simply reverts the effect: ceiling above threshold means more distortion when the signal gets louder, while ceiling below threshold means more distortion when the signal gets quieter.

Shape Dynamics Examples

Many of the guitar presets use a dynamic destruction curve (check out the crunch section) to replicate the feeling of tube distortion, which usually includes some kind of compression.

You can even simulate analog compressors using gentle distortion curves that adjust the gain dynamically and produce very few harmonics. It is also possible to create custom gates, expanders etc.

When setting up the threshold and ceiling in reverse mode and with large range values, you can also create interesting effects where the distortion only happens on the tail of the sound, when it gets quieter (see the "Reverse" presets).

And do not forget the side chain applications too!

Adding Phase Shift

Phase shifting has two types of impacts: first, with high amounts of phase shift (10 and beyond), smearing will start to be audible around the center frequency, a bit similar to a sweeping filter. Second, it will produce phase cancellation effects between the dry and wet signals when blended together using the mix knob.

The latter is a typical effect used in analog distortion circuits that can produce very interesting distortion tones.


As described earlier, you can use oversampling to improve the quality of the distortion and avoid aliasing. Oversampling increases audio quality but uses more CPU, so this is a tradeoff between quality and performance. Further more, at higher sample rates the difference may not be audible, depending on the audio signal and the amount of distortion.

Pre and Post Filters

The pre and post filter are similar to parametric equalizers, but with several twists: emphasis and post filtering steps often require radical settings compared to what you would use an EQ for.

Also, you may have noticed the presence of a comb filter, in addition to usual cut, peak and shelving filters:

It can be used to add color to the sound (most often on the post filter, but not only). A typical use case is when you want to replicate the phase cancellation effects produced by room or cabinet reflections, or the combination of several microphones.

Also, when building a filter shape to be reused in "easy" mode, keep in mind that the three pink filters as well as the hi cut filter will define how the LOW, MID, TREBLE and TONE controls affect the signal.

Using the Gate and Compressor

While the gate and compressor at the input of the signal chain can be used for creative purposes (check out some of the radical factory presets!), their main purpose is to control the dynamics at the input of the plug-in: you will usually setup the gate to catch the noise, and the compressor to limit the dynamics: for heavy distortion, pre-compression is often fully part of the tone.

Reference Curves and Tone Matching

Both the pre and post filters give you the ability to load reference filter curves that have been measured using Blue Cat's FreqAnalyst Multi, as shown for example in this tutorial:

Approximating the rsponse of a cabinet with the post filter

You can create a filter curve that mimics the response of the measured gear. To get the perfect tone, the match is not required to be exact: you just need to make sure that the main characteristics of the response are reproduced. Keep in mind that the measuring process may also add its own artifacts - typically room interferences when measuring cabinets.

Also, the idea here is to use such references as a starting point, to build your own tone. If you really need an exact replica of the frequency response, you will probably want to use an impulse response instead.

Note: if you are measuring gear such as guitar amplifiers, you will need to make sure that you can measure the preamp (for the pre-filter), and the power-amp / cabinet combination (for the post filter) separately.

Chaining Several Instances

Using a plug-in chainer such as Blue Cat's PatchWork or directly in your DAW, you can chain several instances of the plug-in to create different tones. For example you can try a pedal preset in front of an amp preset to create a very high gain tone on guitars.

Blue Cat Audio Plug-Ins Basics

This chapter describes the basic features that are common to all our plug-ins. If you are already familiar with our products, you can skip this part.

User Interface Basics

About Skins

Like all Blue Cat Audio plug-ins, Blue Cat's Destructor uses a skinnable user interface. It means that the appearance and behavior of the user interface can be entirely customized.

Especially with third party skins, the experience may be quite different from the one offered by the default skins that we provide. However, our plug-ins and our skinning engine have several standard features that will be available whatever your favorite skin.

More information about custom skins can be found in the skins section.

The Main Toolbar

In most skins, an optional toolbar at the top of the user interface gives you access to the main options and settings of the plug-in:

Presets Area

At the center of the toolbar, you can see the current preset area (the "Default Settings" box). It displays the name of the current preset, with a "*" at the end if it has been modified since loaded.

The arrows on the left and right let you navigate thru the (factory and user) presets available for the plug-in.

Clicking on the preset name opens the presets menu which lets you manage the presets of the plug-in.


The icons in the toolbar give you access the to the following commands that are detailed in the next paragraph:

Icon Name Function
Menu Open the main menu
Undo Undo
Redo Redo
Manual User Manual
About About

The Main Menu

The main menu is available from the main toolbar, or if you right click anywhere on the background of the plug-in:

  • Presets: opens the presets menu to manage presets.
  • Preset Skin: opens the skins menu to choose the skin for the current preset and manage alternative skins for the software.
  • Undo/Redo: undo or redo the latest modifications. This includes all changes made to the current preset settings such as MIDI or automation preferences.
  • Presets Settings: open the presets settings window. It lets you change the skin, MIDI and automation settings for the current preset.
  • Global Settings: open the global settings window. It lets you change the skin, MIDI and automation settings that are used by default in all instances of the plug-in (if not overridden by the current preset).
  • User Manual: open this user manual.
  • Check for Updates: opens up our website to let you check if any update for this software is available.
  • Get More Skins: get more skins for this software.
  • Legal Information: browse licensing and misc legal documents.
  • About: displays the “about” dialog box.

The Title Bar

In most skins, an icon bar is located below the main toolbar. The first commands are the same for all plug-ins:

From left to right:

  • Smooth Bypass: smoothly bypass the plug-in (just like a power button).
  • Window Opacity: reduce the opacity value by turning the knob, and make the plug-in window transparent. (the result may depend on the host application).
  • Show/Hide MIDI and Automation Control Settings: show/hide the buttons that give access to direct MIDI/Automation setup for each parameter in the user interface. This button will show or hide dropdown menu buttons that popup a MIDI/Automation setup menu described here.



Here are a few examples of typical controls you will encounter in the user interface of our plug-ins:

slider slider knob button Text control

Interacting with Controls

You can interact with the controls of the plug-in interface either with the mouse or the keyboard.

Setting the keyboard focus on a control (so that it responds to key strokes) may be automatic (when you pass the mouse over it it gets focus) or manual (you have to click on the control to set the focus on it). Note that all host applications behave differently regarding keyboard handling. In some applications you may not be able to use all keys described later in this manual to interact with our plug-ins. It is usually made obvious to you to know the active surfaces of the skin (the places where you can click with the mouse): the mouse cursor usually changes when you can do something on a control. In the default skins delivered with the plug-in, the cursor changes to a small hand or an arrow to tell you when your mouse is over an active control.


Various mouse movements will let you interact with the controls:

Mouse Interaction Action
Left Click Acquire focus and start dragging or push (button)
Left Click + Alt Key Set the value to default
Left Double Click Acquire focus and launch the “fine tuning” edit box (except button):
Right Click Set the value to default
Mouse Wheel Increment or decrement the position (focus required)
Mouse Drag Change the control position depending on mouse movement (except button)


All control widgets support the following keys (note that some of them are caught by the host and thus never forwarded to the control. For example in Steinberg Cubase SX you cannot use the arrow keys to control the plug-in):

Keys Common to All Controls

Key Action
Up Arrow Small increment of the position (up or right)
Down Arrow Small increment of the position (down or left)
Left Arrow Same as Down Arrow
Right Arrow Same as Up Arrow
Page Up Large increment of the position (up or right)
Page Down Large decrement of the position (down or left)
+ Small increment of the value of the control
- Small decrement of the value of the control
d Set to default value (same as mouse right click)
e Opens the 'fine tuning' window to precisely set the parameter:
SHIFT When the key is down, the fine tuning mode is on, and you can modify the value with better precision when moving the mouse, the mouse wheel or using the keyboard. Just release the key to get back to the normal mode.

Keys Specific to Buttons

Key Action
Enter Pushes the button


To get started with the plug-in and discover its capabilities, a couple of factory presets are provided. You can also save your own presets and recall them later for other projects. Our plug-ins propose a full-featured preset manager to let you save, browse, organize and recall its presets.

The Presets Menu

The presets menu can be opened from the main menu or the main toolbar. It displays the list of presets available for the plug-in as well as commands to load, save or organize presets:

  • Factory Presets: shows the list of factory presets delivered with the plug-in.
  • "Folder A" to "User Preset Z": user presets and categories.
  • MIDI Program Change: activate MIDI Program Change support (see below).
  • Load: load preset from file.
  • Save: save current state to last loaded user preset.
  • Save As: save current preset to a file.
  • Copy copy preset to the system clipboard.
  • Paste paste preset from the system clipboard, if available.
  • Save As User Default: save the current state as the default preset. This preset is used every time a new instance of the plug-in is created.
  • Clear User Default: reset the default preset to its factory state: this makes the plug-in forgets the custom settings you might have saved as a default preset.

More about Presets

There are two types of presets: factory presets (read only) that are provided with the plug-in, and user presets that can be created and stored by the user.

The user presets are stored in a subdirectory of the documents folders of your profile ("Documents" on Mac, and "My Documents" on Windows): Blue Cat Audio/[Plug-in Name]/Presets. Each preset is stored as an individual file. You can create folders and subfolders in the Presets directory to classify your presets, as shown in the example below:

If you save a preset named "Default" in the root Presets directory, it will override the factory default preset (that's what "Save As Default" does). To restore the factory default preset, you can just remove this file or use the "Reset Default" command.

MIDI Program Change

It is possible to load presets remotely using MIDI "Bank Select" and "Program Change" messages. To enable this feature, select a MIDI channel to receive the events from in the MIDI Program Change menu item from the presets menu:

This setting is a global preference (shared accross all instances of the plug-in). Once activated, the plug-in menu will display the bank number followed by the preset number for each preset:

Every root folder is considered as a new bank, starting with the factory presets (bank 0). Program and bank numbers may change while you add folders and presets, so you should be careful when naming them if bank and program numbers matter to you. It is recommended to use folders to make this task simpler. As a side note, sub folders do not define additional banks (all presets contained in sub folders are associated with the current bank.

As specified by MIDI, bank select messages are not used until a program is actually selected.

MIDI Implementation note: the software supports all types of Bank Select methods. You can use either MIDI CC 0 or MIDI CC 32 to select banks. If both are used simultaneously, they are combined together so that you can use more banks (in this case CC0 is LSB and CC32 is MSB, and actual bank number is 128*CC0+CC32).

MIDI and Automation Control

Blue Cat's Destructor can also be remotely controlled via MIDI using MIDI CC ("Control Change") messages or automation curves, if your host application supports it. It is possible to customize the channel, control numbers, range and response curve used for each parameter in the settings panel available from the main menu (see the Plug-in Settings chapter for more details).

MIDI and Automation Settings Menu

Most skins also provide the ability to change MIDI and automation settings for each parameter directly in the main user interface. When this feature is activated using the corresponding title bar button, dropdown menu buttons appears next to main controls:

Clicking on this button shows the MIDI/Automation settings menu:

  • MIDI Learn: launches MIDI learn mode for the control: touch your MIDI controller and the control will learn from it the MIDI channel and CC number. To end the learn mode, reopen this menu and deselect the option.
  • MIDI Unlearn: deactivates MIDI control for this parameter.
  • Settings: launches the advanced settings panel described below. This controls the settings for the current preset.

Advanced MIDI and Automation Settings

You can completely customize the way the plug-in is controlled by automation and MIDI. For a global view of all parameters at a time, you can use the Plug-in Settings window for the current preset which is available from the main menu.

MIDI Settings:

  • Enable MIDI: enable/disable the MIDI control of the parameter.
  • Channel: MIDI Channel for the parameter control. If set to 0, the plug-ins will accept Control Change Messages from all MIDI Channels (MIDI Omni mode).
  • CC: Control Change Number.
  • Learn: click on this button to activate the MIDI learn functionality. When it is activated, you can move your MIDI controller, and the plug-in will automatically set the MIDI Channel and CC Number.

MIDI and automation settings:

  • Response: response curve of the MIDI or automation control: from very fast to slow control.
  • Min: minimal value of the parameter when MIDI controlled or automated.
  • Max: Maximum value of the parameter when MIDI controlled or automated.

Note: if the Min value is higher than the Max value, the response curve will be reversed: increasing the control value will decrease the parameter value.

Note: if you double click on the parameter text control boxes for the max and min values, a “fine tuning” edit box will appear and let you change the min and max values with more precision:


Check our online tutorial for more screenshots and more examples of our plug-ins user interfaces.

Blue Cat's Destructor Parameters

All parameters described below can be automated and controlled via MIDI if your host application supports it. You can precisely define this behavior in the settings panels described later in this manual.

The parameters of this plug-in exposed for automation and MIDI control are described below:

Name Unit Description
Bypass the effect.
In Gain dB Input gain, right at the input of the plug-in, before any processing occurs.
Side Chain
Selects the signal used for shape dynamics: input, comp, gate, preamp or external (for external side chain).
G Threshold dB Threshold for the gate: the gate starts reducing the gain when the signal is below the threshold.
G Ratio
(Compression) ratio applied to the signal by the gate when the signal is below the threshold. Set to 1:1 for no effect.
G Attack ms Attack time for the gate.
G Release ms Release time for the gate.
C Threshold dB Threshold for the compressor: the compressor starts reducing the gain when the signal is above the threshold.
C Ratio
(Compression) ratio applied to the signal by the compressor when the signal is above the threshold. Set to 1:1 for no effect.
C Attack ms Attack time for the compressor.
C Release ms Release time for the compressor.
Makeup Gain dB Gain to be applied after the compression stage, to compensate the gain reduction.
Pre Filter
Pre Enabled On/Off Enable of disable (bypass) the pre-filter module.
Pre LC Frequency Hz Cutoff Frequency of the low cut filter.
Pre LC Slope dB/Oct Slope of the low cut filter. When set to 0 dB/Octave, the filter is not active
Pre LS Frequency Hz Cutoff Frequency of the low shelf filter.
Pre LS Gain dB Gain of the low shelf filter (BASS control). When set to 0 dB, the filter is not active.
Pre P1 Frequency Hz Center Frequency of the first peak filter.
Pre P1 Bandwidth Octaves Bandwidth of the first peak filter.
Pre P1 Gain dB Gain of the first peak filter.
Pre P2 Frequency Hz Center Frequency of the second peak filter.
Pre P2 Bandwidth Octaves Bandwidth of the second peak filter.
Pre P2 Gain dB Gain of the second peak filter (MID control).
Pre P3 Frequency Hz Center Frequency of the third peak filter.
Pre P3 Bandwidth Octaves Bandwidth of the third peak filter.
Pre P3 Gain dB Gain of the third peak filter.
Pre HS Frequency Hz Cutoff Frequency of the high shelf filter.
Pre HS Gain dB Gain of the high shelf filter (TREBLE control). When set to 0 dB, the filter is not active
Pre HC Frequency Hz Cutoff Frequency of the high cut filter.
Pre HC Slope dB/Oct Slope of the high cut filter. When set to 0 dB/Octave, the filter is not active
Pre Comb Frequency Hz Frequency of the first peak/notch of the comb filter.
Pre Comb Mix % Amount of wet vs dry signal in the comb filter. Negative values produce out of phase filtering.
Pre Gain dB Gain at the output of the pre-filter module.
Pre Analysis On/Off Enable or disable the spectrum analyzer at the output of the pre-filter module.
Destruction - Shape Dynamics
Destruction On/Off Enable of disable (bypass) the destruction module.
Dyn Range % Amount of dynamics sensitivity for the destruction curve ("DYNAMICS" control in easy mode).
Dyn Attack ms Controls how fast audio level boosts impact the dynamics of the destruction curve.
Dyn Attack Shape % Attack shape for the envelope detection. Positive values will slow down the attack, while negative values will speed it up (see the operation chapter for more details).
Dyn Release ms Controls how fast audio level drops impact the dynamics of the destruction curve.
Dyn Release Shape % Release shape for the envelope detection. Positive values will slow down the release phase, while negative values will speed it up (see the operation chapter for more details).
Dyn Threshold % "Cold" point that defines the range for shape dynamics (see the operation chapter for more details).
Dyn Ceiling % "Hot" point that defines the range for shape dynamics (see the operation chapter for more details).
Destruction - Advanced Options
Oversample 1x to 4x Oversampling ratio for the destruction stage.
Shift Freq Hz Center Frequency for phase shifting.
Shift Amount 0-100 Amount of phase shift at the center frequency.
Destruction - Curve Shape
X+ & Y+ Down, Up, Max
Coordinates of the control points for the upper part of the destruction curve.
X- & Y- Down, Up, Max
Coordinates of the control points for the lower part of the destruction curve. Used only if "Symmetric" is set to "No".
Smooth % Smooth the destruction curve (use higher values to remove edges to reduce higher order harmonics).
Rectify % Amount of rectification for the lower part of the destruction curve, for an asymmetric shape.
Bit Depth bit Simulates bit reduction by quantifying the distortion curve.
Shape Mix % Acts like a dry/wet control but applied to the destruction curve.
Destruction - Main Controls
Drive 0-11 Controls the amount of distortion.
Downsampling ratio at the output of the destruction stage (sampling rate reduction).
Anti Alias
Amount of anti aliasing to use during sampling rate reduction. Use 0 for maximal aliasing artifacts.
Mix % Amount of wet versus dry signal for the destruction module.
Gain dB Gain at the output of the destruction module. Used to compensate gain changes caused by the distortion.
Post Filter
Same as Pre Filter
Out Gain dB Gain at the output of the plug-in, before the brickwall limiter.
Limiter On/Off Enable or disable the 0 dB brickwall limiter.

Plug-in Settings

In addition to the controls offered in the main user interface, Blue Cat's Destructor has various settings that let you fine tune the behavior of the plug-in. You can choose to change these settings either for the current preset or globally for all instances of the plug-in.

The Global Settings Window

The settings available in this window apply to all instances of the plug-in, for all presets, if not overridden in the presets settings. Consider these settings as “default” settings.


You can change the default skin for all instances of the plug-in: write the skin file path in the text edit box or click on the button to open a file chooser dialog. If you have several instances of the plug-in opened in your session, you will have to re-open the user interfaces of these plug-ins to see the skin change.

Click here for full size screenshot

The output data refresh rate can also be customized for all instances of the plug-in. It controls the refresh rate of non-audio data produced by the plug-in (parameters, curves...). It also controls the refresh rate of output MIDI CC messages or output automation data. The higher the refresh rate, the better precision, but also the higher cpu usage (some host applications may also have trouble recording MIDI data at high refresh rates). The default value is 50 Hz.

Global Control Input Settings (MIDI and Automation)

The plug-in offers a couple of settings that affect the way it is controlled by MIDI messages or automation. While the first settings only apply to MIDI control, the "Control Response", "Min" and "Max" settings apply to both automation and MIDI control.

For each parameter you can define a default MIDI channel and CC number. You can then control the plug-in with an external MIDI controller or one of our plug-ins that generate MIDI messages.

The settings below are available for each plug-in parameter.

MIDI Settings:

  • Enable MIDI: enable/disable the MIDI control of the parameter.
  • Channel: MIDI Channel for the parameter control. If set to 0, the plug-ins will accept Control Change Messages from all MIDI Channels (MIDI Omni mode).
  • CC: Control Change Number.
  • Learn: click on this button to activate the MIDI learn functionality. When it is activated, you can move your MIDI controller, and the plug-in will automatically set the MIDI Channel and CC Number.

MIDI and automation settings:

  • Response: response curve of the MIDI or automation control: from very fast to slow control.
  • Min: minimal value of the parameter when MIDI controlled or automated.
  • Max: Maximum value of the parameter when MIDI controlled or automated.

Click here for full size screenshot
(generic screen shot, does not correspond to the actual plug-in parameters)

Note: if the Min value is higher than the Max value, the response curve will be reversed: increasing the control value will decrease the parameter value.

Note: if you double click on the parameter text control boxes for the max and min values, a “fine tuning” edit box will appear and let you change the min and max values with more precision:

The Current Preset Settings Window

In this window you can change the settings for the current preset of the current instance of the plug-in only.

Preset Skin

You can choose to use the global skin setting or to change the skin for the current preset. This way you can have different skins for different instances of the plug-in in the same session in order to differentiate them.

Click here for full size screenshot

Preset Control Input Settings (MIDI and Automation)

Use the global settings or override them for the current preset. The parameters are the same as for the global input settings.

Click here for full size screenshot
(generic screen shot, does not correspond to the actual plug-in parameters)

About Skins

Blue Cat's Destructor integrates Blue Cat's skinning engine that allows you to customize the user interface. You can download alternate skins for your plug-in at the following address:

If you don't find a skin that fits your need or if you want a custom one, you can choose to create your own skin.

Choosing the Skin

There are two ways to select the skin of your plug-in: you can change the default (or 'global') skin, or change the skin for the current preset only (either in the preset settings page or from the main menu). The global skin applies to all plug-in instances (choose this one if you want to use the skin used by default, regardless of the session or preset), whereas the current preset skin only applies to the current preset of the current plug-in instance (use this one if you want to change only the skin for the current session/preset).

Note: in some host applications, the plug-in window won't resize automatically when you choose a skin with a different size. In this case, just close the window and re-open it: it will be displayed with the right size.

The Skins Menu

The skins menu can be opened from the main menu. It displays the list of skins available for the plug-in as well as commands to manage the skin used by default when no preset skin has been selected:

  • First Section - Factory Skins: shows the list of factory skins delivered with the plug-in ("Default" and "Light" in this example).
  • Second Section - User Skins: shows the list of user skins that have been installed in the Documents Skins folder for the plug-in (see below).
  • Use Global Skin: use the global skin for the current preset/session (unloads any custom skin previously selected for the current preset).
  • Load: opens a file browser dialog to manually select the skin from the file system.
  • Save As Global Skin: use the current preset skin as the global skin (loaded by default if no preset skin has been defined).

Installing User Skins

To select user skins directly from the skins menu, install them in the "Skins" directory available in the plug-in's documents folder:

[Your Documents Folder]/Blue Cat Audio/[Plugin Name]/Skins/

The skin engine will scan this folder for new skins (xml files) and display them in the menu. The skin files should be in the root skins folder or in a subdirectory inside this folder: subdirectories are not scanned recursively.

Other Methods to Select Skins

You can also select the skins in the settings panels available from the main menu:

The global skin (used by default if no preset skin has been selected) can be changed in the global settings pane. The current preset skin can be changed in the preset settings page .

Create a Custom Skin

You can create custom skins for your plug-in in order to adapt it to your exact needs. You can change its look and feel and make it completely integrated in your virtual studio!

Just read the Blue Cat's Skinning Language manual and download the samples for the tutorial on You can get ready to create your own skins in a few minutes. You can then share your skins on our website.


Plug-ins Formats

What are DirectX (DX), Audio Unit (AU), RTAS, AAX and VST plug-ins?
VST, Audio Unit, RTAS, AAX and DirectX plug-ins are software components than can be used in "Host" Software (such as Blue Cat's PatchWork, Pro Tools, Cakewalk Sonar, Steinberg Cubase or Wavelab, Sony Vegas, Logic Pro, Garage Band, Ableton Live...) in order to perform some MIDI and/Or Audio real-time Processing tasks. To be more precise what we usually call directX plug-ins is actually a "DirectShow Filter". VST is owned by Steinberg, DirectX by Microsoft while Audio Units is the property of Apple Computers and RTAS and AAX are owned by AVID.
How can I use your plug-ins?
Download and install a host software, then download and install the plug-ins from our page. They will appear in the host "effects" menu. If you are using a DirectX host with our MIDI controllable plug-ins and they do not show up in you host list, you might need to use our freeware DXi Manager. Note that our plug-ins are sometimes shown in the "MIDI controllable audio effects" or "soft synths" sections in some host applications.
Where can I find a host?
You use Blue Cat's PatchWork standalone application to host any VST or Audio Unit plug-in for real-time operation. There are also many commercial or freeware hosts that will suit your needs. You can find a long list of applications here. You can also use demos of Cubase, Wavelab, Ableton Live, Tracktion, or Sonar software, which are usually available on the companies websites. On the Mac, Garage Band is part of the system and can be also used to host our Audio Unit plug-ins.
What are the main differences between DX, VST, RTAS, AAX and Audio Units?
VST is a protocol that works on several platforms (Mainly Windows, MacOS, BeOS, and some Linux platforms use it as well) whereas DirectX is Microsoft Windows only, and Audio Units are available only on the Mac. RTAS and AAX are available on Mac and PC, but only for Pro Tools products (AVID). AAX plug-ins are compatible with Pro Tools 10 and higher, whereas RTAS versions are compatible for Pro Tools 10 and lower versions.
What is the difference between DXi and DX effects?
DXi effects are MIDI controllable DirectX plug-ins. It's the same as DX effects plus MIDI control.
Which version (VST, Audio Unit, RTAS or DX) should I use in my host application?

See our software download help page for detailed explanations about how to choose the right plug-in format and platform.

In general, we recommend using VST over Audio Unit on Mac (when both are supported), particularly for the plug-ins that can output automation or MIDI CC messages.
Where can I find more information about this topic?


I have installed my software and it is not listed as an application. Why? What can I do? How can I launch it?

Most software you can purchase on this website is plug-ins for host applications. It means you need another application to use it. See the "Plug-ins Formats" section in this FAQ for more information.

I have installed my plug-in and it does not show up in my host application. What can I do?

First check that you application supports DirectX, Audio Unit or VST plug-ins.

If you are using the DirectX version, check that your host application supports DXi plug-ins (MIDI enabled DirectX plug-ins). If it does not, it may remove it from the DirectX plug-ins list (some applications such as Sony Vegas 5 and Cool Edit Pro are known to do this). In this case, use our DXi Manager free utility and disable the MIDI capabilities of the plug-in. You may need to reinstall the software again before it shows up into your host application. For more information about this topic please read our DXi in Sony Vegas tutorial (it is applicable to other applications than Sony Vegas).

If you are using the Direct X version and your host application supports DXi, check that the plug-in does not appear in the 'virtual synth' or 'synthesizers' category. If you wish not to use the MIDI capabilities of the plug-in and use it as a regular Direct X plug-in, you can download the freeware DXi Manager and disable the MIDI capabilities of the plug-in.

I have installed my plug-in on windows 64-bit, checked the items above, and it still does not show up in my host application. What can I do?

You are probably running a 32-bit application. If that's the case, you need to install the 32-bit version of the plug-in: the choice for 32 or 64-bit is not determined by the operating system (64-bit windows can run both 32 and 64-bit applications), but by the host application that you are using.

Why are there two plug-ins called xxxx(Mono) and xxxx(Stereo) installed ?
"Mono effects" (which are effects that do not make any difference between left and right channels) are bundled this way for performance reasons. Some developers just deliver a stereo Version which also processes (twice) mono streams. The "(Mono)" plug-in is to be used with mono streams, and the (Stereo) one with stereo streams. The effect itself is the same in both cases but the number of processed channels is different: this may drastically improve performance for CPU intensive plug-ins.
How do I uninstall my plug-ins?
Open the Windows configuration panel/ Add Remove Programs, and choose 'Remove' on the corresponding plug-in. If you have installed the VST plug-in zip file version, just delete the corresponding dlls.
Why do your plug-ins need an installer on Windows? Do they modify the registry or system settings? Why not providing just a dll?

Our plug-ins require several additional files for default settings, skins and miscellaneous data. We provide an installer for our customers' convenience. Our installers do not modify the system settings or the Windows registry, except for the DirectX versions registration. Our installers won't harm your system.

Software Version

How do I know the version of the plug-in I am using?
You can see the version information in the about box: right click on the background of the plug-in user interface and select "About". The product version is also available in the Windows Add/Remove Programs Window.
Why do newer versions of a plug-in override older ones (they have exact same name and IDs)?
Because newer versions improve previous ones. When a new version is released, older versions are not supported anymore. In some cases the new versions may be installed as new products (compatibility reasons, major changes...), but it is explicitly documented on the product page.
A new minor version of a product I purchased some time ago is available. Where can I download the update?
The new version can be downloaded from the same place where you downloaded the original version. All information is contained in the email you received when you purchased the product. Your registration number has not changed either.


A new minor version of my plug-in has been released. Where can I download it?
When you purchased the plug-in, an email containing the information to download and register your software has been sent to you. You can download the new version from the exact same location as the first time.
I have downloaded a new version, do I need to uninstall the previous version?
No, you don't, except if it's specified on the product page, in the "history" section. Just run the installer and it will upgrade your software.


What is "Parameters Automation"?
The parameters of an effect can be automated in most host software. It means that you can record the changes you do during playback or recording so that it's replayed when playing back again. It's a way of sequencing parameters changes the same way you do with Audio or MIDI data.
What is "Smooth Update"?
When changing parameter values in real time or replaying a song where parameters have been automated, our plug-ins compute intermediate values between parameter changes in order to avoid "clicks" and "pops" that may occur otherwise. It results in a non audible smooth parameters update and lets you freely use automation or MIDI control to change the effects in a song.
Do your plug-ins support MIDI Control?
Yes they do. They offer precise control over the mapping of MIDI Control Change (CC) messages to parameter values: you can adjust both the channel and CC number as well as the response curve of the control. Since some of our plug-ins are also capable of creating MIDI CC from the audio signal, they can all be connected for real time signal-dependent audio effects. See our MIDI Control in Sonar tutorial for an example.


This manual only covers the basics of Blue Cat's Destructor. Our website offers many additional resources for your Blue Cat's Destructor plug-in and is constantly updated, so keep an eye on it! You will find below a few examples of available resources.


Many Tutorials are available on our website. They cover a wide range of topics and host applications.

You can find here a list of tutorials related to the Blue Cat's Destructor plug-in.

Extra Skins

We encourage our customers to propose their own skins for our products and we often propose alternative skins to let you choose the one that best suits your needs. You can check Blue Cat's Destructor skins page to get the latest skins.


As you can see in the history log below, we care about constantly updating our products in order to give you the latest technology available. Please visit our website often to check if Blue Cat's Destructor has been updated, or subscribe to our Newsletter to be informed of the latest news about our products.

Note: minor version updates are available from the same location as the original full version download (link received by email upon purchase). The demo version publicly available on our website will not let you register.

You can also follow us on twitter and facebook for almost real time updates notification, and subscribe to our YouTube channel to watch the latest videos about our software.

Versions History

V1.11 (2016/12/29)

  • Memory usage optimization: unused graphical elements are now unloaded on plug-in window close instead of next time the window is opened.
  • Fixed (Windows): on older versions of Windows 7 with auto update turned off, the plug-in could fail to load.

V1.1 (2016/12/15)

  • Lock each module or the user interface to prevent changes when loading presets.
  • Bypass, input and output gain parameters are now independent from presets.
  • Added more than 200 new visual styles with vintage knobs.
  • New contrast setting for spectrogram display.
  • Spectrogram display is not reset anymore when resized.
  • Touch screen support improved: enlarged shape dynamics arrows and shape controls.

V1.01 (2016/11/22)

  • Changed demo limitations: up to 5 instances allowed, bypass time changed to half a second, and bypass parameter is not affected anymore.
  • Fixed: no more comb filtering when using the mix knob with oversampling.
  • Fixed smooth bypass crossfade (used to produce clicks).
  • Plugin now requires Mac OSX 10.7 and newer.

V1.0 (2016/10/11)

First release.

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