Audified U73b Compressor Version 2 Review – Warm Character

Audified has recreated the rare Telefunken U73b compressor in software form, but has it done justice to a legend with its second version? Bill Francis takes it to the limit…

Audified U73b Compressor


Manufacturer Audified
Price $149
Contact +420 516 454 769
System requirements OS X 10.9 to 10.12, 32-bit or 64-bit AU, VST 2/3, or AAX host
Windows 7 to 10 32-bit or 64-bit VST 2/3 or AAX host – ReiLok Account (no USB dongle required)


Most producers and mix engineers already have a good selection of compressor plug-ins at their fingertips, so if a new one comes along, it needs to offer something a bit different to attract any real attention.

It makes sense then, that Czech company Audified chose to painstakingly model the circuitry of the rare and highly sought-after Telefunken U73b tube compressor, designed in Germany in the late 1950s. It was originally designed to keep levels consistent and protect against overloads in FM broadcasts, but during the 60s, 70s and 80s, the U73b was used as a compressor for vinyl mastering. It has since become something of a legend among engineers due to its unique characteristics and can now be found on sale for well in excess of £4,000.

Keeping it Real

We took a look at Version 2 of Audified’s compressor plug-in which, from Version 1, offers an updated GUI, sidechain functionality, automatic output levelling and English labelling text – the previous version only offered authentic German-language labels similar to those on the original hardware unit.


As is the case with the original U73b compressor, there’s no ratio control, but the soft-knee characteristics present here mean the compression ratio slowly increases as the level of the incoming audio rises, offering plenty of flexibility.

The plug-in has a limiter mode as well as compression mode, which gives you the option of a higher threshold and higher ratio while keeping a smooth, soft-knee compression sound.

There’s also a release, output-level auto-matching, input/output level parameters and a meter so you can select between input level, gain reduction and output-level metering.
Input/output level controls and metering weren’t part of the original U73b hardware, but they were usually added alongside the unit when used in recording studio setups, and are therefore a welcome addition to Audified’s plug-in.

U is for Unique

Simply put, this compressor sounds like nothing else we’ve tested. It’s not always the most predictable tool, but it certainly offers bags of character and individuality. When subtly used across the master bus, it has an overall thickening effect on your track and seems to push midrange sounds forward, creating an almost three-dimensional effect. When pushed too hard, the U73b reduces your track to a series of short pops and clicks and sounds very unnatural. However, crushing tracks into oblivion is obviously not what this compressor was designed for.

It also really shines when used on individual tracks, as it seemed great for adding life to drum loops and smoothing out bass-guitar recordings. Even when ‘bypass’ mode is selected, the plug-in has a very subtle tightening and focusing effect on your sound, as the signal is still being passed through the virtual circuitry.

The more eagle-eyed will have noticed the high-pass (HPF) button at the top right of the plug-in, which you may be mistaken for thinking is for the sidechain function. In fact, it relates to the high-pass filtering effect of the original U73b unit. This would have been ideal for its original purpose as a broadcast compressor – however, we found that it removed a significant amount of low end when left engaged.

We didn’t think of this as a negative point, though, as these are the kinds of quirks one should expect to find when using a faithful model of a piece of vintage gear. When the high-pass effect is switched off, everything performs as expected and your low end remains intact.

It’s also worth mentioning that if you’re pleased with the sound of the U73b, then Audified has also just released a new valve-saturation plug-in based on the circuitry.

Audified U73b – Alternatives

It’s been around for a few years now and is included as a stock plug-in within Ableton Live, but Cytomic’s The Glue compressor ($99) still does a stellar job of modelling SSL’s classic 80s E-series bus compressor. Also worth a look if you need some vintage flavour on your master bus is the PuigChild Compressor from Waves ($349).

While not being a budget option, this plug-in is fantastic at bringing life and colour to in-the-box mixes.

A Fine Vintage

Overall, this is a great compressor that doesn’t really sound like anything else out there. It’s not a tool you’d want to use for every application, but if you’re looking for a warm, punchy, thickening effect on individual tracks or your full mix, the U73b is ideal.

Just when you think you’ve heard every flavour of compressor possible, something different comes along. The U73b is everything you could ask for in a vintage analogue emulation… characterful, warm and sometimes unpredictable

U73b Compressor – Key Features

  • Modelled on vintage U73b compressor
  • Updated GUI for Version 2
  • Sidechain support
  • 2 licences included
  • VST, VST3, Audio Units and AAX formats