SL473 by SmackLabs FREE ‘Compressor, Limiter, & Expander’

SL473 by SmackLabs

SL473 by SmackLabs

SmackLabs has launched the new SL473 Compressor, Cleaner, and Expander plugin, which is based on a vintage analog device from the 1970s and is completely free. SmackLabs has been creating free plugins based on analog audio equipment since 2011 (for example EQ Neve, Channel Strip SSL, DBX Compressor, and more), initially the plugins were only accessible in VST2 format for 32-bit Windows computers, but in December 2020, a compatibility update for Windows 64-bit operating systems was released: Compressor SL63x (based on the dbx163x) and Logic Channel (based on the SSL 9000 console).

SL473 by SmackLabs FREE 'Compressor, Limiter, & Expander'


VCA designed the SL473 Compressor, Limiter, and Expander plugin based on the Danner Cassettes type module, the Neumann U473 Black. The Neumann U473 analog model was created from the 1970s until Neumann discontinued making analog mixing consoles in the early 1990s, and it was the most popular limiter for “cutting” records in the vinyl era. It’s known for its clean and transparent compression, so you may fully compress the typeface without the usual side effects.

This compressor, like the original hardware, has a minor learning curve, according to the developer. However, if you understand how this compressor works, you’ll see how it manages dynamics in a very musical manner.

The yellow knobs on the left side of the GUI control the expander; the expander can be activated with the ‘On Expander’ switch, and you have the ‘Recovery’ and ‘Threshold’ knobs (with respect to Attack and Ratio these are fixed).

The black and red knobs control the Compressor and Limiter, respectively. The durations of ‘Attack’ (0.25 – 2.5 – 25 ms), ‘Recovery’ (0.1 to 10s and Automatic mode), ‘Ratio’ (red knob that, when adjusted in LIM, works as a Limiter), ‘Compr Gain’ (allows us to add gain to manage the fixed Threshold), and ‘Output’ (from -6 to +4 dB) are the parameters that we can alter.

The SL473 can be used in mastering. This compressor was employed for the final stage of vinyl cutting, which, from what I understand, was the procedure where what we now know as Mastering began to be developed. It can also work on MixBus, DrumBusses, Voices, and Glue compression by providing transparent compression.

Final Thoughts

SmackLabs did an excellent job modeling vintage devices. They have emulated various plugins in 32-bit versions, including the SL532 Console EQ, SL543 Console Compressor, SL84 Console EQ, LOGIC CHANNEL, and SL63x. They have, however, upgraded several of their plugins to 64-bit, as previously mentioned.

Their product is well-liked by producers, and it’s great to see them return with 64-bit versions. Like “VoS” products, most producers stopped using theirs because they had to use third-party software such as “jbridge”, to load their plugins in 64-bit DAWs, which made the plugin unstable and buggy.

The SL473 sounds to me to be a very musical compressor with typical CPU use. Almost anything may be used with this plugin. It works well on the vocal bus, the drum bus, and even the mix bus. Does it sound like an actual device? Probably not, but they’ve done a nice job of creating a pleasant-sounding compressor that tries to replicate the color of classic VCA devices (Neumann 473).

SmackLabs’ plugins are now only available for Windows OS, but I hope to see Mac OS versions in the near future. Consider supporting the developer on their Buy Me A Coffee page if you use their product, and give them the motivation to create even more fantastic things.

Download 'SL473'

The SL473 plugin can be downloaded for free from the developer SmackLabs’ official buymeacoffee Page (Link Below). While you may download this and other SmackLabs plugins for free, please consider making a donation to the developer’s official BuyMeCoffee account.

Download Here: SL473

System Requirements

MAC OSX Requirements

  • Not Supported (Yet)

WINDOWS Requirements

  • Windows 64-bit VST
Attitude Music IssueSL473 by SmackLabs FREE 'Compressor, Limiter, & Expander'

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