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Virtual buss compressors

Virtual buss compressors

virtual buss compressors

bus compressors, or by their other name, glue compressors, are designed to unite groups of channels with a compatible sound in the same atmosphere. There are many excellent virtual buss compressors on the market today, both simulations for historical hardware and brand-new plugins. Today we will review the 3 connected plugins from slate digital, the best simulation for legendary hardware.

What is a virtual buss compressor?

The virtual buss compressors software package combines 3 of the industry’s most well-known bus mix compressors. Slate Digital has added another part that combines the 3 sound processors in one unique processing unit. The purpose of the plug-in is to unite everything you need to do dynamics on channel groups/mix buses and even on the master, three tones of first-class compressors with preset settings that will satisfy most of your needs, and if not, full parameters to control your sound.
The three compressors are: FG-RED, FG-GREY, FG-MU


If you are a fan of sound hardware like me, you must have heard about the legend of the Focusrite red 3. Even if not, here is a summary. The red 3 is a TEC award-winning VCA compressor that top-class sound engineers found to be a huge technological innovation with a unique sound. Unlike the other VCA’s that turn from compression to limitation
The RED 3 completely separates compression followed by limiting with the help of 3 VCAs in the side chain. In addition, as only Focusrite knows how to produce, the compressor has a low noise threshold and excellent distortion. You will find controllers for precise control, such as attack, release, and ratio, in addition to some unique features of applying true stereo.

by focusrite



The second simulation in the virtual buss compressors series is a simulation of the bus compressor from the SSL 4000 console. The advanced design and processing capability as a separate unit are among the best in the world to date. Therefore when designing visualization for dynamic processing units, the SSL must be there.
The ability to control the compressor as a sidechain and as an integral part of the mix simultaneously (because it was on every channel) gave sound designers excellent results.

The compression ratio and threshold controls determine how much compression will be applied to the signal. The attack and release controls determine how quickly the compressor responds to signal transients (initial peaks). And finally, the makeup gain control allows you to boost the overall level of the compressed signal. One common way to use an SSL bus compressor is on an entire mix. By compressing the mix, you can bring up its overall level without worrying about individual tracks clipping. This can give your mix more punch and clarity. Another way to use an SSL bus compressor is on individual tracks or groups. For instance, compress drums or vocals to make them sit better in the mix. Or you might want to compress all of the instruments in a specific frequency range .


The third compressor in the series is a simulation of a limiter – a compressor, very rare today, that goes by the name Fairchild 660-670. It is an aggressive compressor (in size and sound) known for its fast attack. Due to its aggressiveness but warm color, the sound engineers of the Beatles and many others found the Fairchild suitable for singing (if you know how to use it correctly). Its most common use is in compressor glue for channel groups.

virtual buss compressors

Why use a bus compressor?


As beginners in editing and mixing music, we learn to apply effects and processors to the channel.
This is simple, but using bus channels in our mix is necessary to get a professional and finished sound.
Here are some main reasons for using a bus compressor:

  • drums: to get a uniform dynamic range/sound color for the percussion
  • frequency ranges: to highlight/hide in the mix
  • vocals: to unite different choirs/vocal channels
  • All mix: to get uniform color and corrections at the macro level
Read also about Best reverb plugins

Virtual Buss Compressors - full review

So slate took these compressors and all their features and created something renewed and valuable in every mix.

Here’s another little secret: Slate Digital analyzed the Red and discovered it was a unique beast. The attack and auto-release work excitingly and are very musical, but the real magic they found was in the output section! They found that just pushing the makeup gain a few dB did some insane things to the sound! A little push and things got a ton more punchy, fat, and aggressive. 

So Slate decided to do something that the original unit could not put that output transformer effect on a knob called Drive. When you push the Drive knob, you get a beautiful punch and articulation of the transients, and you can control just how much you want, regardless of whether or not you use the makeup gain! 


In any case, careful attention was paid to recreating the unique nonlinearities of the circuit paths that give each compressor its distinct tone – including their transformers, tubes, VCAs, amplifiers, phase distortions, harmonic distortions, and timing. VBC is perfect for adding a final professional touch to your mixes. 




  • FG-GREY: the classic British console compressor
  • FG-RED: the red-faced compressor 
  • FG-MU: Fairchild 670 tube compressor
  • The integrated processing unit of the 3 compressors
  • Function as separate plug-ins in your DAW or Slate’s Virtual Buss Compressors Rack

How to use a bus compressor


The use of dynamic processors of this type is done very gently due to their tendency to be aggressive in affecting a wide sound. When using a compressor, you want to set a small ratio with a threshold that touches the peak and a breathing attack.

Assuming you have a basic understanding of what a bus compressor is, let’s move on to how you can use one in your mixes. 

First, identify the main groove or feel of your track and ensure the drums and percussion are sitting well in the mix. 

Once you have a strong foundation, bring in the remaining elements one at a time, compressing each as you go. As you’re mixing, pay attention to the relationship between the different frequencies and instruments in your mix. 

A good rule of thumb is to compress frequencies that compete with each other. For example, if you have two guitar parts that are both fighting for space in the mid-range frequencies, try compressing them both with a bus compressor. This will help even out their levels and give each one its own place in the mix. 

When using a bus compressor, it’s essential to leave some headroom, so the compressor doesn’t start distorting your signal. A good general rule is to aim for around -6dB of gain reduction. This will ensure that your signal remains clear and articulate while still getting the benefits of compression. Finally, don’t be afraid to experiment with different settings and plug-ins until you find something that works for you. 

Here are some valuable tips you can take to your BUS mix.

  • Use each parameter sparingly.
  • Use the bus to strengthen the dominance of instruments
  • Incorporate EQ while still changing for the desired tone (if needed)

What is the busses compressor used for

Channel groups, and parallel compression There is a lot of use in compressors of this type due to their being gentle and capable of a wide effect.
But if you want to take the color of the compressor to use it in individual channels, do the compression in a gentle and calculated way.



Music producers and sound engineers can use several bus compressors in their plugins. 
I can’t think of better simulations than this series of plugins for any use of glue, groups, etc.
Hope this guide was historically and technically enriching. See you in the next guide.

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