Royal Compressor Review-An Honest Opinion After Heavy Use

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Analogue compressor plugins are a must-have in every producer's arsenal. But with so many plugins claiming accurate analogue emulation, finding the right plugin to suit your needs is challenging. In this article, we spent weeks putting the United Plugins' Royal Compressor to the test to see if it's worth your hard-earned music bucks or not. Scroll on to find out what we thought.

United Plugins' Royal Compressor (Quick Review)


Quality of Hardware Emulation
Analogue Colour and Warmth
Quality of the Saturation
Applications on Vocals, Synths, Guitars, Drum Busses
GUI and User Experience
Ease of use for a recent buyer


The Royal Compressor is a distinctly colourful vari-mu compressor with an instantly recognizable vintage sound. While being highly reactive to your signal, the Royal Compressor is excellent at adding subtlety. The random saturation algorithm creates true valve saturation, making it a no-brainer on vocals, acoustic guitars, and drum buses.


Is The Royal Compressor Worth It? (TL;DR Verdict)

Compatibility: VST, AU, AAX Compatible ( Windows 8/10, 32 & 64 bit. Mac OS X 10.10+, 64-bit only) Intel AMD Processor equipped with SSE2.

The Royal Compressor is worth it. While we criticize it for being a one-trick pony, the Royal Compressor can bring out nuances that other digital compressors might miss by a mile. It's great for adding punchy, warm analog crunch to your signals, and just general dynamic range control.

Though great for adding vintage charm to your tracks, it does fall short in terms of versatility. However, that's not what it's for – you'd use the Royal Compressor alongisde a more transparent compressor like Fab Filter Pro C or Denise Audio Dragon Fire.


βœ… Instant Analogue Colour.

βœ… Random saturation algorithm creates genuinely creamy and pleasant saturation

βœ… Reacts well when used in tracking vocals, bass, and synths.

βœ… Free second-hand version with vintage broken knobs and all.

βœ… Elaborate Release and Hold parameters inside the recovery section.

βœ… Highly useful Trim function which cuts your signal up to -100dB.

βœ… Upto 8x upsampling with hardly any latency.


❌ Doesn't react well to quick transients. A lot of peaks don't pop out.

❌ Too colourful to be applicable in different production scenarios.

❌ Unless you're primarily going for an analogue sound, $154 is overpriced.

What Is The Royal Compressor And What Does It Do?

The Royal Compressor aims to bring the vintage sound of variable-mu compressors to your DAW. Modelled on three EMI RS 124 units, the Royal Compressor is similar to Abbey Road's RS124 compressor plugin. A highly elaborate ‘Recovery' section, backed by three varying attack models, makes this an ideal candidate for capturing nuances.

Instant color, staggering looks, and a highly efficient GUI with seamless upsampling keep the Royal Compressor on par with its competition.

How Does It Sound?

The royal compressor plugin is slow at catching transients (especially with drums) but sounds fantastic on most things you run through it. It's great for adding warmth to male vocals, as well as sophistication and roundness to your bass sounds.

We found that the plugin can be used best by inserting it on most tracks within your project, as it has a homogeneity to it that's rare to find. You don't need to go overboard with this compressor. Even with the input dial at 1, you'll get a fair amount of body out of it.

Though we didn't think it was great for clinical mixing, because it was too colourful for corrective work, it's fantastic for color.

Check out some of the results we got below from using it:

Sound Examples

Vocals + Synth (Before Compression)

Creating a Track Stack, we've applied the compressor on the stack as well as the individual tracks.

VHS Tape Synth (Before Compression)

A VHS Tape Synth is used to exhibit the plugin's subtle compression

Fretless Bass (Before Compression)

A fretless bass played by fingers is used to display the details captured between the fast-moving fretless notes.

Chords+Melody (Before Compression)

A melody is played over some chords to show how the compressor reacts in a melodic environment.

Drums+Bass (Before Compression)

A track stack with a rolling electric bass on top of a Canadian Roots kit is used here. Compression is applied on the stack and the individual instruments.

Snare (Before Compression)

We set up a drum loop focussed on the snare to display the compressor's lack of ability to capture fast-moving transients.

Vocals + Synth (After Compression)

The Input is set at 1 and the Attenuator is set at -5. Model A attack is chosen along with a fast release at 2. The Autogain is switched off and the Saturation is set to 100%.

VHS Tape Synth (Before Compression)

The Input is set at 1 and the Attenuator is set at -3. Model A attack is chosen along with a slow Hold at 4. The Autogain is switched on and the Saturation is set to 60%.

Fretless Bass (After Compression)

The Input is set at 1 and the Attenuator is set at -5. Model A attack is chosen along with a fast release at 2. The Autogain is switched off and the Saturation is set to 80%.

Chords+Melody (After Compression)

Aggressive Compression brings out the intensity in the playing. Notice how the intent of the player gets captured by the compressor.

Drums+Bass (After Compression)

While we made the drum kit quite aggressive, we held back on the bass. The bass uses no saturation and uses a very Hold set to 5. Model A attack is used. Notice how the bass acts as the underbelly of the drum kit.

Snare (After Compression)

The Input is set at 3 and the Attenuator is set at -7. Model A attack is chosen along with a medium release at 4. The Autogain is switched off and the Saturation is set to 85%. Notice how the transients of the snare are hardly captured while the kick gets awkwardly tight.

What Features Do I Get With The Royal Compressor?

Classic '60s Analogue Sound In A Plugin!

RS124 altec compressor

Modelled using three RS124 units from the Beatles era, the plugin oozes analogue vibes! This classic British device sounds as realistic as a plugin can get to emulating the legendary RS124 vari-mu compressors from the '60s.

The Royal Compressor captures analog compression perfectly. However, it doesn't appear to fully emulate the original characteristics.

Either way, we found it produced warm, crunchy tones that are perfect for vocals and bass.

Experience The Magic Of Vari-Mu Circuit Emulation

united plugins royal compressor review

The Vari-Mu or Delta-Mu compressor circuitry is generally known for its analogue warmth due to the use of vacuum tubes in the hardware units. A Vari-Mu compressor emulation, like the Royal Compressor's primary role, is to precisely mimic how the circuitry and tubes affect the sound. 

Unlike other Tube Compressors, which use tubes for the make-up gain, the Royal Compressor does not. This is instead found on the gain reduction section called the “Output Attenuator”.

The Royal Compressor plugin might seem a bit like a one-trick pony at first, as it has a lot of limitations. But, the plugin is awesome at the primary role it's supposed to play, which is – to offer realistic Vari-Mu vacuum tube hardware emulation.

Creamy Saturation To Satisfy Your Analogue Cravings!

Being able to dial in desired levels of valve saturation in your analogue compressor plugin is a great feature for producers and engineers.

While this feature is absent in the original hardware units, we feel it is a brilliant addition to the plugin version.

The saturation is designed around a random saturation algorithm that oscillates to create an effect similar to a real hardware saturation unit.

The Royal Compressor plugin opens with saturation at 100% by default when you switch the plugin on, making the first impression quite staggering, as you feel the analogue flavour in its entirety.

While the saturation is great for most things you run it through, you need to keep an eye on the percentage dial.

With the plugin being extremely sensitive to the nuances of a player's pluck or strike, the saturation can completely wash out the detail if kept at high values all the time.

royal compressor united plugins

For example, in this image above from our bass + drums sound sample, we've kept the saturation at 0% on the bass.

Since we are using a fretless bass guitar played by fingers, we found that even a small amount of saturation nullifies the details that the vari-mu plugin captures.

Such an example can also be applied to fast-moving guitar solos or double-kick drum patterns used in heavy metal music. This saturation might not do the trick in places with too many notes playing quickly.

The Royal Compressor plugin's general saturation is too coarse with a wide spread to be efficient in fast-moving material. However, it's great for most other instruments that aren't transient heavy.

Great for synth sounds in any genre, the Royal Compressor's saturation truly shines with Lo-Fi sounds, VHS tape sounds, bass, bowed instruments, and drones.

More often than not, it's best to max out the saturation because of its subtlety.

Modelled On Three Different Hardware Units With Varying Attack Times

The Royal Compressor plugin was made using three different hardware units of the original RS124 Vari-Mu compressor from the '60s, which emulates 3 different attack & release times. United plugins have used the classic British device, that was previously used by the likes of the Beatles and more for this.

Rivalling Abbey Road's attempts at modelling the same hardware unit, the Royal Compressor plugin is right on the money, and this emulation expands on the competition, giving you the ability to choose the different hardware sounds.

They call these A, B, and C models:

  • Model A is fast and crisp, using a quick attack & release
  • Model B has a medium attack and lies somewhere between A and C
  • Model C adds the greatest amount of analogue mojo, with its slow attack times

While great for vocals, synths, and drum busses, the varying attack feature is great for recording MIDI instruments in real-time and testing which mode sounds best.

This was especially true when playing the native Bosendorfer grand piano on Logic Pro X. We modulated the settings as we played the grand piano to find the best setting.

In this case, Model A sounded the best, capturing the notes in full detail. When we moved from B to C, we found the compressor was washing over the transients of what we were playing. The high saturation values reacted similarly – washing the details away.

A quick video showing how Royal Compressor sounds on vocals, bass, and drums.

Handling fast transients isn't the Royal Compressor's USP. We feel it's better to use it for slow compression (an area where this plugin is fantastic). But with that being said, there were many instances where this idea was proven wrong. One such instance was while using it on a Bosendorfer grand piano we just mentioned.

That is the beauty of realistic analogue emulation plugins – you never know what might surprise you. With realistic circuitry modeling, the three attack modes can spit out surprising results in the most unexpected of situations!

Minutely Control Your Releases In The Recovery Section

We now come to the ‘Recovery' section, which is by far the Royal Compressor's most interesting feature.

With release times ranging from the fastest to the slowest, the dials span from values 1 to 6.

The release times are intricate, adding a level of realism to live or non-electronic instruments. While dialling in release times on the vocal track (in our sound samples), we found a noticeable difference when you switch release times from 1 to 5.

Affecting the way the singer breathes out after a phrase, the intricate release times can change the intention behind the vocal phrase. The degree of human realism that we felt while turning the knobs was quite staggering.

You can also shape the intensity with which a guitarist or pianist's fingers move from one note to the next. While that is of course what release times are supposed to do, the Royal Compressor's finesse and sophistication in shaping note releases are un-missable!

Ultra Slow ‘Hold' Function To Make Time Stand Still

The ‘Hold' function under the Recovery section allows you to capture the last peak that went through the compressor and hold it in a compressed state for a long time. Coloured in red, the Hold function moves from values 1 to 5.

Though not exactly the same as freeze reverb, it acts in a similar fashion. While freeze reverbs take your reverb tail and sustain it, the Hold function freezes your peak or transient and releases it exceptionally slowly.

We tried this on the vocals and found a great deal of relaxation in how the syllables were released. Comparing the Hold value set at 5 to the Release value set at 1 will instantly give you an idea of what the Hold function is doing.

Boost And Attenuate At The Same Time For Analogue Mojo

The unique thing about the Royal Compressor plugin is that it's a Variable-Mu compressor emulation, which means that the vacuum tube is used for reducing the gain. So, as you send your audio through the plugin, the vacuum tube gauges the level of the incoming signal and begins the gain reduction process.

As a rule of thumb, the more the incoming signal level, the more the gain reduction is applied. So, this makes balancing the Input and Attenuate knobs extremely vital while using this plugin.

For example, while using the plugin on the vocal sound sample, we found that the best place to start is at a similar negative and positive value on the Attenuator and the Input. If dialling in -9 on the Attenuator, set the Input to +9.

As the Attenuator has the tube-based variable gain reduction, increasing your volume here is better than on the Input knob. So if the Input is set at +9, you can Attenuate it to -7 or -6 to get more punch.

By following this process while using this plugin, you're using the compressor's main USP, which is the vacuum tube-based variable gain reduction, to increase volume. This is the perfect way to inject analog character into your tracks.

Adding A Human Element To Your Sounds 

Details of finger attacks on a bass or guitar add a human touch to your track. While it is possible to do that in an EQ by surgically boosting the exact overtones of the notes being played, it is impossible to add such analogue warmth while doing so.

We found that to add the human element to your tracks; you need to tweak the knobs in tandem. You can group the knobs into two sections. The Attenuator, Input, and Saturation can be tweaked together to get your desired level and thickness. The Model section and Recovery can be worked on separately to sculpt the player's intensity and humanize his note transitions.

Test The Second-Hand Edition For Free With Ruptured Knobs And All!

There's additionally a second-hand edition that you can use to test Royal Compressor with before you decide to purchase the plugin.

The second-hand versions have the same user interface and saturation algorithms, and users can switch to the original paid version anytime they like.

The Input, Attenuator, and Saturation work just like the original version. However, you don't get to modify your attack times. The dial that controls the switching between the three RS124 models is additionally broken, and the autogain isn't active either.

You will not be able to dial in intricate release times or use the Hold function, which really handicaps the use of this compressor.

Besides that, it's a great free compressor plugin to use before purchasing the full thing.

The best part about the second-hand version is that there aren't any volume glitches or noise interference when you use them. They are genuinely usable in your projects and are free for life – not a demo with any annoying white noise etc.

It Puts Itself To Sleep When Not In Use

Amazing power savings can be expected from using the “Intelligent sleep on silence” feature. The Royal Compressor is equipped with an automatic shutoff feature for when it is not used.

With such flexibility, the Royal Compressor can be applied to all your tracks without causing much fuss.

This is a cool feature that should be available on all plugins and helps to save CPU massively.

What About The Technical Stuff?

How Hard Is The Royal Compressor On The CPU?

We stress-tested the Royal Compressor on the Mac Mini M1 2020, running Big Sur 11.2.1 with 8GB RAM, and an 8-core CPU. Even with 15+ instances of the compressor open simultaneously, there was no noticeable lag. You can tweak your dials as freely on the 15th track as you would on the 1st. The processing is almost unnoticeable.

“Intelligent sleep on silence” is a real lifesaver for people working on computers with lower specs. The plugin detects whether the user is using it or not. The plugin goes into sleep mode if it's not in use. 

This allows you to virtually have the Royal Compressor on most of your tracks and not worry about your CPU's overall processing. The computer could save its CPU usage for something else while the Royal Compressor automatically goes into “Intelligent sleep on silence.” 

What Does My System Need To Run It?

While the Royal Compressor's intricate and photorealistic GUI looks like it might be heavy, it's pretty light in reality. Any computer that can run 5-7 instances of 3rd party plugins at a time should be able to handle the Royal Compressor.


  • Anything above Mac OS X 10.10 should work.
  • 4 GB RAM is a must. 8GB+ should work comfortably.
  • 64-bit only.
  • Intel/AMD/M1 Processor equipped with SSE2.
  • iLok isn't necessary for activation.
  • License files can be dragged and dropped manually for activation.


  • Windows 8/10/11 should work.
  • 4 GB RAM is a must. 8GB+ should work comfortably.
  • 64-bit only.
  • Intel/AMD Processor equipped with SSE2.
  • iLok isn't necessary for activation.
  • License files can be dragged and dropped manually for activation.

What Is The GUI Like?

When you open the Royal Compressor, the first thing you notice is how cool it looks. The vintage look and feel are instantly recognizable. Working on it feels as if you're modulating a real hardware unit. The Saturation is set to 100% by default. So, as soon as you switch on the plugin, it sounds absolutely spectacular!

The resizing on the Royal Compressor is worth checking out. The bigger the plugin window, the cooler it looks as you see the greenish panel and screws in vivid detail.

Operating the ‘Trim' and ‘Recovery' controls in a larger size is also a treat. An arrow on the bottom right corner allows you to resize the plugin to your liking, giving you the freedom to make it as big or small as you like.

The Royal Compressor's knobs are pretty good compared to most analogue emulations on the market. But we wish the Recovery and Model switching stuck to each value more tightly, because they're quite fiddly.

What's The Utility Like? Any Standout Features?

The ‘Intelligent sleep on silence' is an awesome feature that is bound to save you a lot of CPU. Switching off by itself when not in use, the Royal Compressor decides when it needs to go into sleep mode. Since it's quite light, to begin with, you can literally have the Royal Compressor on all of your tracks.

Right-clicking anywhere across the plugin opens up a wide variety of hidden functions.

When you do, you get access to the presets folder, manual, GPU acceleration, intelligent sleep, version info, and more.

The oversampling in this plugin is additionally seamless. Even at 8x, the compressor performs as well as it does at a regular sample rate.

Furthermore, dialling in accurate values is quite intuitive. Simply double-click on a knob or a certain parameter, and a digit dial will open up. You can use this to write detailed values with decimal points in.

What Are Others Saying About The Royal Compressor?

Countless reviews across the internet praise the Royal Compressor for its vintage analog warmth. But, that being said, many users don't find value for money within the limited settings offered. While the saturator is well received, many users wonder how the attack on the Abbey Road RS124 and the Royal Compressor could behave so differently if modelled on the same hardware unit.

After scouring the internet, we found some interesting comments and opinions that opened our minds to how others feel about the analogue plugin. We've listed some of them below:

Royal Compressor KVR Audio Review #1
Royal Compressor KVR Audio Review #2
Royal Compressor Reddit Review #3
Royal Compressor KVR Audio Review #4
Royal Compressor Reddit Review #5

How Does The Royal Compressor Stand Up To The Competition?

The Royal Compressor, Summit Audio's TLA 100A, and Slate Digital's FG-MU have all come within touching distance of the original tube hardware units they emulate. Since they're all in the same price range, it comes down to which kind of analog colour you prefer.

The Summit's saturation is comparable to that of our Royal Compressor, adding grit and subtle distortion to all it touches, and also works well as a glue compressor.

The FG-MU is an intricate buss compressor with a dedicated high-pass filter. This gives it the slightly edge over the Royal Compressor, which could've added true high-end shimmer with its distinct tube colour.

In the field of vari-mu or tube compressor emulations, Universal Audio's Fairchild 660/670 poses a severe threat to all the three emulations we mentioned above. The $149 Universal Audio 660/670 is capable of more than just adding color.

However, you need an external, expensive audio interface made by UA themselves to run it.

If you already own a Universal Audio interface, then the Fairchild 660/670 is a great choice.

If not, then all three plugins we mentioned are well worth checking out. They boast a unique characteristic sound that is distinctly noticeable. 

Ultimately, with non-transparent compressor plugins, the specifications sheet has little relevance. As they all have distinct characteristics, it comes down to what you personally connect with.

You can grab your Royal Compressor at Plugin Boutique.

The Verdict– Is The Royal Compressor Worth It?

United Plugins' Royal Compressor (Quick Review)


Quality of Hardware Compressor Emulation
Analogue Colour and Warmth
Quality of the Saturation
Applications on Vocals, Synths, Guitars, Drum Busses
GUI and User Experience
Ease of use for a recent buyer


The Royal Compressor is a distinctly colourful vari-mu compressor with an instantly recognizable vintage sound. While being highly reactive to your signal, the Royal Compressor is excellent at adding subtlety. The random saturation algorithm creates true valve saturation, making it a no-brainer on vocals, acoustic guitars, and drum buses.


If your music is transient-heavy or is primarily digital-based and transparent, we doubt the Royal Compressor can add much value, due to its slow attack nature.

While the saturator might work great for something like Glitch-Hop or Lo-Fi, the attack and release times might not be the best suited for heavy metal or drum and bass.

If you need a compressor that adds analog warmth, color and saturation, then we highly recommend grabbing the compressor, but use it on less transient heavy genres.

To get an idea of how the compressor reacts to various signals, it's best to start by trying out the demo for free. The second-hand version gets activated automatically after 15 days. A bit of noodling on the Saturation and the default attack and recovery sections can give you an idea of how the compressor reacts to your style of music.


I like the Royal Compressor, but it's quite expensive for just adding analogue colour. Can I go with the Royal Compressor Second Hand Edition?

We highly recommend the Second Hand Edition if you don't see yourself using the Royal Compressor a lot. While a few knobs might stop working after the 15-day trial, you'll still get instant analog color, without the in-depth control.

If you happen to fall in love with it, you can always upgrade to the paid version. It's important to note that, after the trial, you are still able to use the plugin freely, without the in-depth control.

Do I really need an analogue compressor plugin?

It really depends on what kind of music you make. Owning an analog plugin isn't a must, but it can add a layer of realism and warmth to your music. If your music-making is primarily digital, we suggest going for a compressor plugin with more knobs first before getting an analog compressor.

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