5 Analog Audio Compressors You Absolutely Must Know!

Last updated on 10/31/24 par Adrien

Apart from perhaps preamps, there is probably nothing better than an analog compressor to bring warmth and character of analog processing to a mix.

At least, a good analog compressor.

Because while there are many different models, not all live up to the hype.

In fact, if you are looking for hardware compression but your budget is very low, I would recommend you to opt for a good plugin like the Novatron from Kush Audio: you will have a much better sound at your disposal.

Although… our friends at FMR Audio will make me contradict myself, as their Really Nice Compressor (RNC) is quite a reference in (home) studios since it offers excellent sound at a very low price.

But generally speaking, we must admit that some compressors stand out from the crowd. At least, some vintage compressors — that is to say, equipment designed in the 60s and which is still considered a safe bet today.

The problem is that they are often quite expensive.

So, for this article, I decided to present you with these essential compressor models and indicate the type of application they excel in (provided you master, of course, the basics of audio compression), while recommending a number of hardware clones as well as plugin simulations.

Thus, whether you are looking for hardware for your studio or VSTs, you will find everything you need 🙂 !

Note: If you are not yet comfortable with compression, know that I offer a course on Projet Home Studio that will explain everything you need to know on the subject and thus significantly improve your mixes.

👉 If you are interested, click here to discover the training.

1. Urei 1176

Analog Compressor 1176
Universal Audio reissue of the Urei 1176

Ah, the 1176… !

Clearly one of the most famous compressors ever created.

Designed in 1967 by Bill Putnam, it features a gain reduction circuit based on JFET transistors allowing for extremely fast attack settings (from 20 µs to 800 µs), while the release ranges from 50 ms to 1100 ms.

Operating in feedback configuration (the level detection circuit is located after the amplifier that performs the compression), the 1176 is characterized by a number of fixed ratios accessible via push buttons: 4:1, 8:1, 12:1, and 20:1.

What’s interesting is that although these ratio options are primarily designed to work independently, it is possible to press all the buttons at the same time.

This results in a new type of compression sometimes referred to as “All Button” or “British Mode”: the attack and release are altered, and the signal gains saturation due to a much more aggressive compression curve.

Typically, this kind of effect is particularly effective on drums — but be careful to use it in moderation 🙂

It’s not surprising, since the 1176 excels at compressing percussion tracks. Indeed, its ultra-fast attack offers optimal control over transients.

However, it is also possible to use it for many other applications. I am of course thinking of vocals, but also bass or electric guitars.

It is worth noting that there are no fewer than 9 different versions of the 1176 that have been marketed by Urei, excluding the latest “official” reproduction from Universal Audio.

Clones (hardware)

Plugins (software)

2. Teletronix LA-2A

Analog Compressor LA-2A
Universal Audio reissue of the Teletronix LA-2A

Very often mentioned in connection with the 1176, the LA-2A is an absolute must-have in the studio.

Invented by Jim Lawrence in 1958 with the goal of enabling signal compression for broadcasting, the LA-2A was first produced by Teletronix before the brand was acquired by Urei.

Although it is a so-called tube compressor, the compression itself is achieved by an opto-electronic circuit while the tubes are only used in the amplification circuit.

Let me explain:

The LA-2A includes a “T4 cell.” This cell corresponds to an electroluminescent panel coupled with a light-sensitive resistor.

Depending on the signal level, the panel lights up or turns off. And it is these variations that generate the compression effect that we hear.

I never record a bass without LA-2A, and I never record drums without a 1176

Billy Bush (Garbage, The Naked and Famous, Muse...)

Of course, as one might expect from this type of compression circuit, the LA-2A is a so-called “program-dependent” compressor. This means that the attack, ratio, and release parameters will vary depending on the variations in the input signal. In other words, this analog compressor will not react the same way to a transient or a long, continuous signal, even if they are at the same level.

To give approximate values, the attack is on average 10ms, while the release (at several levels) can last from 0.5 to 15 seconds.!! 😮

In terms of use, I would tend to recommend this type of compressor primarily on vocals (and why not in combination with the 1176 mentioned above) as well as on bass guitar.

It indeed has the ability to warm up the sound while leveling out signal variations harmoniously — all this, even with high gain reduction levels.

Clones (hardware)

Plugins (software)

3. dbx 160

Le DBX 160

The DBX 160 is the very first model designed by the dbx brand (whose name stands for decibel expansion — in case you didn’t know).

Produced since 1976, it is a highly efficient compressor/limiter using patented technology based on a VCA (Voltage Controlled Amplifier) and an RMS level detector (while many other compressors work based on peak level).

Beyond the vu-meter, which gave it the nickname dbx 160VU to help differentiate it from other existing models, it is characterized by simple and relatively easy-to-control settings.

There are indeed only the Threshold, the Ratio (1:1 to 120:1), and the output gain that can be adjusted.

Moreover, although it is a mono compressor, it is possible to link two dbx 160s together to work in stereo.

In terms of sound, it offers something very different from the LA-2A and 1176 presented earlier, likely because the compression circuit topology is of the feed-forward type, which has the effect of reducing distortion. The compression itself, recognizable by ear, remains relatively clean, but there is still a tendency to gain a certain coloration (particularly in the mids).

Unfortunately, the dbx 160 is not at all what I would call a versatile device. It has nothing to do with a 1176 that can be placed on any track.

Here, we have a compressor that will have two main uses:

  • drums, on which it excels at adding punch in a very recognizable way;
  • and bass guitar, which it can easily reinforce the body to achieve a thicker sound that stands out much better in the mix.

The dbx brand has since been sold to the Harman group, but many compressors branded dbx 160 or with similar numbers are still being produced.

On this point, I would like to “warn” you if you are hesitating to buy one of these new models: some are very effective, and others much less so. In fact, although the numbering seems similar, the circuits have little in common with the original dbx 160VU. So don’t think you are buying a reissue: that’s not the case 🙂

Moreover, to my knowledge, there is also no DIY kit to assemble yourself, as the VCAs used were specifically manufactured for dbx devices. They are therefore rare, and cloning the dbx 160 proves to be a daunting task.

So I will only recommend plugins simulating this compressor 🙂 :

Plugins (software)

4. Fairchild 670

A Fairchild 670 compressor
A Fairchild 670 compressor (photo modified from Mac Morrison)

The Fairchild 670 is somewhat of a monster on this list.

It’s true: 11 transformers, 20 tubes, 2 inductors… the beast weighs 30 kilograms and is 6 rack units high (6U).

We are clearly dealing with something out of the ordinary — even if most of the transformers are not actually in the direct path of the audio signal and are rather used to manage the high voltages that pass through the circuit.

The Fairchild 670 is a stereo derivative of the mono Fairchild 660 compressor, which was designed in the early 1950s.

At that time, Rein Narma, a young Estonian engineer who had emigrated to the United States and was making mixing consoles for people like Les Paul, designed a device very different from what was available on the market.

He sold the production license to the Fairchild Recording Equipment Company, founded by Sherman Fairchild, which allowed for the successive birth of the 660 (which seems to have been designed for broadcast) and the 670 (mastering-oriented for record cutting, as it can work both in stereo and mid-side mode, thanks to a matrix that separates the signals.).

The Fairchild is a sound glue, everything sounds good with it.

Tony Visconti (David Bowie, T-Rex...)

Its use by Geoff Emerick on most Beatles albums suggests it: the Fairchild 670 sounds very good, and this on all kinds of sources to which it brings a particular character.

This versatility is notably linked to the different attack and release settings available, some of which are even program-dependent (see explanations above).

Of course, it can be used to compress stereo busses, but it proves to be just as effective on individual tracks: vocals, drums, piano…

The problem is that very few Fairchild 670s were produced, making the device particularly rare — and its price particularly high: €40,000 to €50,000!

Fortunately, there are some more affordable hardware reissues, as well as plugin simulations that do their job very well 🙂 :

Clones (hardware)

Plugins (software)

5. SSL Quad Compressor

The Quad Comp from SSL
© Joel Hamilton – Used with permission

Finally, the last one on this list but just as famous as the compressors I mentioned earlier, the Quad Compressor from Solid State Logic.

This is a stereo compressor based on a VCA that can be found in all SSL 4000G consoles (although today it is also available in rack format). The operating principle is quite simple, as the voltage of the input signal triggers an amplifier that adjusts the output gain.

Clearly, this compressor is famous for one thing: bus/master compression.

That is, for groups of tracks.

Forget about individual track compression: in some cases, it can work, but it’s clearly not where it excels.

Indeed, it can add a tremendous amount of sonic glue — thus providing real cohesion to the mix. With a few quick adjustments, it is possible to link the different tracks while adding punch, especially through interesting behavior in the low frequencies.

While various types of settings are applicable, there is a sequence of “magic settings” that often sound very good (or at least can serve as a good starting point):

  • Slow attack = 30 ms
  • Fast release = 0.1 ms
  • Ratio = 4:1

Once these settings are made, adjust the threshold to achieve a maximum of 4 decibels of gain reduction… and enjoy the sound 🙂 !

But what if you don’t have an SSL mixing console?

Well, fortunately, the relative simplicity of the electronic circuit means that there are many versions, both official and unofficial, of this excellent bus compressor — both in terms of hardware and audio plugins:

Clones (and reissues — hardware)

Plugins (software)

In conclusion

There are certainly other compressors that could potentially be mentioned here.

For example, I think of the API 2500 or the famous Distressor from Empirical Labs… it’s hard to mention them all.

However, if you think this list is incomplete, and that other compressors should definitely be included, please leave a comment below! 🙂