The Empirical Labs Distressor and Its Emulations: Hear How 6 Plugins Compare to the Original

With more than 30,000 units around the world, the Empirical Labs Distressor is a staple of the recording industry, adding its unique compression to countless records in a great number of the world’s professional studios. We are huge fans of the Distressor at Influx Studios, where I am a producer and engineer making electronic music and alternative rock. There isn't a track I have produced or mixed in recent years that doesn’t have it somewhere on the song.

It’s fitting that there would be many software plugins that try to mimic all or some of its distinct mojo. But if you’re in the market for one of these plugins, how are you to tell which one best emulates the original? Or maybe one doesn’t hew closely to its analog counterpart but has a distinct flair all its own?

Luckily, I’ve tested six Distressor-style plugins, weighing the good and the bad, from one of the least expensive to Empirical Labs’ own software version. My quick takeaways:

  • The Empirical Labs Arousor not only emulates the original closely, but also includes even greater functionality.

  • The UAD Distressor is as close as you can get with a plugin to the analog Distressor.

  • The SKnote Disto is a good and versatile emulation, but does not perform as well as others. Unfortunately, I was not able to test the latest version.

  • The Slate Digital FG-Stress is a more affordable plugin with good top-end sizzle and lows, though it lacks a bit of depth and control.

  • The Sly-Fi Digital Deflector is a fun, original take on the analog unit.

  • The Cocell Productions SOR8 is not a high-quality emulation, but, as the least expensive on the list, it is capable of some nice distortion and light Distressor-like compression.

Below, you’ll find my notes on each. And farther below, you can hear audio clips of drums, bass, and vocals run through no compressor, the analog Distressor, and each of the the six plugins, side-by-side, so that you can hear the differences and similarities for yourself.

But before we get to the tests, let’s get you caught up to speed on the original.

A Quick History of the Distressor

Dave Derr, whom I had the privilege to talk to for this article, is the creator of the Distressor. Before founding Empirical Labs, Derr was an engineer at Eventide, where he helped to make the H3000 Ultra-Harmonizer, a multi-effects unit that, incidentally, also became a mainstay in pro studios.

Empirical Labs Distressor

First prototyped in 1994 and officially released in 1996, the Distressor was the first of several pieces of top-end studio gear to come out of Empirical Labs. Derr modeled the Distressor after his favorite parts of the classic 1176 and LA-2A compressors, but it certainly has unique gifts that make it worthy of a place in any studio’s arsenal, even those lucky enough to have such classics at their disposal.

What makes the Distressor unique is the way it makes use of its ratio while giving you an insane amount of control.

For those who might not know, the ratio of a compressor determines how much the unit will blunt a signal that meets or exceeds a given threshold. The 1176 only allows you to decide between four different ratios, though you can use all four simultaneously in what’s called “British” or “All-Buttons Mode,” which engineers use to get an aggressive, distorted sound. The LA-2A doesn’t allow you to set a ratio. Instead, the ratio fluctuates internally based on the strength of the signal.

While rightfully revered, the 1176 and LA-2A definitely have quirks and limitations. The Distressor aims to allow users to mimic what they love about these compressors, including in its EL8-X version the British Mode and LA-2A-emulating "Opto" mode, while offering a range of ratios and a level of control not found on those older units.

A little more than two decades after its release, the Distressor has attracted its own emulators. Derr and Empirical Labs even got into the act themselves, developing the Arousor, which we'll discuss at length below.

If you’ve ever wanted to get a software version, you’ll know just how many options there are available. And while no one has the time to test them all, I’ve certainly made a strong start.

I’ve taken some of the better-known emulations and put them up against their analog inspiration. (It should be noted that, even if the company doesn’t claim a relation, these units are all inspired by Derr’s original.) But this is not an article about the analog vs. digital debate. Instead, I’ve conducted what were, at times, long and tedious tests, in order to find out what’s good and bad about each plugin.

Diving Into the Box

Cocell Productions SOR8 (Cost: $29)

Cocell Productions SOR8

The SOR8 plugin is one of the cheapest Distressor-type plugins on the market. Upon first glance you can see the big knobs just like that of the analog unit. It may not be an exact emulation, but it has some unique distortion that happens when you drive it hard.

Compared to the other plugins, the SOR8’s distortion becomes extremely digital-sounding very fast and can be very sharp on the top end. But it has its place in the arsenal if you want a quick, heavy-handed fix for a distortion effect with a Distressor-like GUI and approach.

The strangest part to me is that the input and output gain knobs are very touchy. When you drive them, they don’t react nearly the same way as the analog gain knobs (which give so much of the Distressor's characteristic sounds).

However, if you want to play around with the different distortion types and drive the input hard enough, you can get some gritty sounds that could find use on an FX bus or as a layered distortion effect.

Sly-Fi Digital Deflector (Cost: $99)

This plugin is modeled by UBK, aka Gregory Scott, the designer behind the many great plugins and hardware units to come out of his Sly-Fi Digital and Kush Audio companies. (UBK also has a take on another classic Empirical Labs analog, the UBK EL7 Fatso.)

As UBK says on the Sly-Fi website, “I can’t give you the original, but I can give you my twisted take on it.”

Sly-Fi Digital Deflector

As such, the Deflector’s distortion characteristics are entirely different from the analog Distressor’s. But the added dirt and grime make it a fun plugin in its own way. Although the ratios are not anything like the analog unit, the way the attack and release reacts with the input gain and ratio is similar to the Distressor.

The effect is a warmer and rounder compression with good harmonic depth. All and all, it gets the job done and offers some new and different takes on the saturation/distortion control. This is a nice one.

SKnote Disto (Cost: $49.99 Intro Price/$299 MSRP for Disto-S)

The Disto from SKnote is a good emulation. The company claims that its new Disto-S is “simply the best emulation of the classic unit,” but unfortunately, I was not able to acquire and test this latest version.

I did, however, find the Disto to be capable of all manners of different levels of compression, and this versatility closely adheres to the original Distressor. So the company does have that characteristic covered.

I did think that I liked the Disto more on some instruments than others. The low-end is not nearly as punchy or tight as the rest in full setting, without a sidechain. The bass frequencies felt loose and didn’t have the depth I was hoping for.

SKnote Disto

When pushed hard it has a digital sizzle that is not like other plugins or the Distressor. It seemed to have much more top-end on vocals than some other emulations and to lose the body of the voice. This is particularly bothersome when following a tube microphone or tube processing, as some of the distinctive body from the tube equipment is made thin by the plugin.

One very welcome feature of the Disto is its British Mode (called “UK Mode” here). To me, it doesn’t quite capture what makes the All-Buttons technique on the 1176 sound so great, but that is, admittedly, a very hard thing to achieve. It is, nonetheless, a very cool addition.

As Dave Derr told me, “The Brit Mode is a really non-linear beast, with sped-up behavior. Very hard to quantify, and as we do some pretty wild modifications of the basic compressor circuit [on the Distressor], it is almost a different product when engaged.” This may explain why so many of the other Distressor plugins lack the Brit Mode feature.

Overall, the Disto is a good take on the original, and for an all-around plugin compressor that relates to the Distressor, it can hit the mark.

Slate Digital FG-Stress

Slate Digital FG-Stress (Cost: $199 with no iLok, $219 with iLok included)

I have not used a lot of Slate plugins, as they always seemed to fall short of my expectations, but my hat is off to them on this one, because it is a huge step above their other products.

They did well re-creating the Distressor to give a familiar and basic use. The FG-Stress has a nice top-end sizzle when pushed hard and retained more low-end than some of the other emulations.

It did rattle more in the lows when “nuked,” or set to the Distressor’s highest ratio setting, which the analog unit and some other emulations of it do not do. I also felt it didn’t glue on a stereo bus or have as much depth. But overall, if you want an emulation that can directly relate to the Distressor’s abilities this could be a good choice.

Empirical Labs Arousor Rev 2.0 (Cost: $299)

This is a plugin made by Derr and Empirical Labs. The biggest misconception floating around the audio networks is the assumption that Derr wanted just to recreate his Distressor in a plugin. Instead, what he has done is add even greater functionality to his classic analog compressor.

Empirical Labs Arousor Rev 2.0 Plugin
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If you try to use the Arousor as a 1-to-1 Distressor plugin (and adjust the settings the same), you will find you have to tweak it to sit as the Distressor does. The ratios were purposely offset to be a tad higher so that Derr could introduce lower 1.5:1 and 2:1 ratios. This was a smart move.

As Derr told me, “Over the years I have developed new tools and new tests to help quantify compressor performance. Over a decade ago I realized that the ratios of the Distressor were generally quite a bit higher at typical settings than their name suggests. That wasn't a big deal in itself, as the ratio curves change with attack and decay settings and there is some ‘play’ in determining a ratio to begin with, especially ones with knees.”

Derr further explained: “By moving all the Distressor ratio names up one, I opened up space for 1.5:1 and a new 2:1 ratio, and made the ratios a little closer to what they actually measure. I know it throws Distressor lovers a little bit, but we put a reminder in the Help Menu, accessible by the Square Blue button in the lower right corner. You really can match a Distressor pretty much indistinguishably if you need to, with the exception of Opto or Brit modes, which are not enabled yet.”

Not enabled yet he says... so what more is there to come? Lots from the sound of it.

All of us that have used the analog Distressor love the original unit for the utmost control that you can achieve in both light and extreme settings. The Arousor does this well and gives even more control with added Attack settings, Saturation control, Dry/Wet knob, and so much more. It is an entirely new beast of its own. It is the Distressor on steroids.

I was curious about this and decided to ask Derr about it. He said, “Once we had it sounding and measuring like a Distressor, we started on the list of ‘dream features’ I had gathered over the years. It was quite a long list, and some of the features were quite complex and experimental. Putting them all in the first release quickly became impractical.”

Empirical Labs Arousor Rev 2.0

So he began to shed light on something Derr and team call “Evolutional Technology,” which, for the users' purposes, means that the plugin is entirely upgradeable as the team launches new features, while still being backward-compatible to a session. That is, it can function the same way on all of your past mixes while still getting the updates and new features over time.

In total, the Arousor is everything you’d want in a Distressor plugin and then some, with more to come.

UAD Distressor (Cost: $299 *must have UAD accelerator/card)

We all know that nothing is as much of a rockstar move as showing up late to the party with a grand entrance.

This is exactly what happened with the UAD Distressor. Literally within hours of finishing this long, in-depth article, UAD put out a “Brand new Distressor plugin endorsed by Dave Derr.”

This news, along with the copious amount of emails from my fellow engineer friends, meant that I immediately had to get and test this one. UAD is a leader in emulations known for their rock-solid quality. Combined with the immaculate timing, I just had to include the new Distressor-style plugin here.

You know one of those moments in life when you are in such disbelief that you say something out loud even while sitting in a room by yourself? That’s what happened. I literally said, “Holy Crap, they’ve actually done it,” while sitting in the studio by myself.

UAD Distressor

I couldn't believe my ears, nor my eyes (because the GUI is so beautiful). UAD have done something the other direct 1-to-1 emulations fell short of: the attack and ratios settings react exactly the same way as those of the original Distressor. I was amazed.

If you are planning to use a Distressor emulation that is literally 1-to-1, this is your new best friend for in-the-box workflow. The only main variation I could hear, which has much to do with the nature of analog and its linear response, is that when linked on a stereo bus the analog version was giving a bit more depth. This could be related to the conversion going on too.

The low-end extension (which you may notice on the bass guitar tests) was slightly less “open” with UAD's plugin than with the analog Distressor, but you could easily fix this with the updated Wet/Dry knob UAD have added, or just simply using the internal sidechain.

Bottom line: UAD have done it.

The plugin is so fantastic that I had to double check with Derr and ask him what he thought. There I found the golden nugget of truth—Derr not only endorsed the UAD plugin but also worked closely with UAD to make it. Well, no wonder then.

The Round-Up

So after many years of being a big-time Distressor user, I was finally able to sit down with the analog unit and the various plugin emulations, listening closely and take meticulous notes. I have attempted to give a complete and unbiased runthrough, finding the strengths and weaknesses of each.

Luckily, you don't have to rely on my notes alone. Listen for yourself to the audio clips below.


Disclaimer for all tests: Not all plugins can be perfectly 1-to-1 tested as they have slightly different settings. So I used metering to level match for input/output. Keep in mind the most important thing about the Distressor is the way the ratio works and interacts with the attack and release settings. In order to achieve this with a plugin it would need extra tweaking sometimes. But this will give you a glimpse of their overall tone or sound.

Drums (Room Mic)

For these tests it is a basic drum room mic setup. Listen to the image and the low-end punch. Listen to how the saturation of the compressors each relate to the low-end and how the depth or image of the room mic opens up or tightens up.

High Settings: Input 5, Attack 4, Release 1, Ratio 20:1

Kick Drum

For these tests I did Extreme Nuked settings. Things to listen for are the depth and low-end of the saturation characteristics. Also, pay attention to the sustain and release of the kick drum.

Extreme Settings: Input 6, Attack 2, Release 0, Output 6, Ratio NUKE

Bass Guitar

For these tests the bass guitar was recorded through a REDD tube saturation DI. This helped to give it extra character before going into the compressor. Listen to how the attack of the bass plays off the Distressor sound.

High Settings: Input 7, Attack 3, Release 2, Output 6.5, Ratio NUKE


For these tests the vocals are recorded with a tube mic into the Thermionic Culture Vulture tube distortion/enhancer unit to retain the lower "chest" to the voice. I set the Distressor and its emulations to control the peaks and let the chest of the voice through while retaining the sibilance and transients. Listen to the mid-range of the voice and the top-end sibilance of the tubes on the voice and how it relates to the compressors.

Peak Control high settings: Input 7, Attack 5, Release 4, Output 6.5, Ratio 10:1

Finally, Some Recommendations

If you want something for FX and distortion characteristics each of our featured emulations have their strengths. They take what is great about the Distressor and run in different directions with it.

Basic 1-to-1

For an all-around emulation, the FG-Stress is a cheaper version to get you nearly there, just as the SKnote Disto can get you some similar results. However, the UAD Distressor takes the crown for direct 1-to-1 mimicry. It is insane how great the attack sounds in comparison.

Something Different

The Sly-Fi Deflector gives depth and warmth with extra distortion features new to the plugin. This can be handy in mixing situations or in production, but is not to be confused as a direct emulation.

The SOR8 can be an inexpensive distortion unit with some Distressor-like capabilities for lighter compression thrown in.

All of the Above

The Arousor, as discussed above, pulls everything it can from Derr’s original and promises more, expanding with each update as he goes through his “dream features” list. It is a gem.

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