UAD Empirical Labs Fatso

UAD Empirical Labs Fatso

This is one cool dude. If you are looking to really add an analog vibe, you can’t do much better than the Empirical Labs Fatso. Everything about it is too much fun!

The UAD Empirical Labs Fatso pretty much does whatever it wants to do, with you sort of guiding it. Even the default, flat settings are eccentric! (Take a look at the charts.)

By the way, in case you didn’t know, FATSO stands for Full Analog Tape Simulator and Optimizer. You can use it as a compressor, but I like to think of it as compression mimicking the way tape compresses. Empirical Labs had more than this in mind, since they mention the 1176, but darn it I like to use it like tape. Subtle compression, the high end getting pulled back a bit by the “Warmth” control, transformer emulation—yes, tape.

I don’t usually make presets for compressors, but since the Fatso is much more than that you can take a look at the manual for my UAD presets. I have my own way of setting it up, and it might give you some new ideas.

Just FYI—

Compressor setting reference:
Buss has a 2:1 ratio, with a slow attack and fast release as well as a soft knee.
G.P. has a medium attack and slow release.
Tracking is an 1176 style.
Spank tries to be an SSL talkback compressor. (Yes, it slams.)

Of course, these can be combined, and also the attack and release can be changed with the (attack and release!) settings. There are lots of possibilities!



  • The “Warmth” button is about the coolest thing ever. (See what I did there.) Want to get rid of digital harshness? This will do it. Basically you are compressing (and distorting slightly) the high end. A setting of 4 or 5 to start, and then see where your material takes you.
  • Adjust the Tranny Level until the LF Sat light is on, then back off a little. UAD talks about low end psychoacoustics. Yeah, ok.
  • Try this on the mix bus. It might seem a little risky, but you can add a lot of mojo along with compression. Keep the compression subtle though, everything subtle.
  • Sorry, this isn’t really a hint but saturation IS distortion. When a signal saturates, it distorts. I guess the word ‘saturation’ is trying to capture the idea of a signal slowly moving into distortion as is evident in some analog gear. It’s not magic—it’s distortion!


[Note: The “Jr” version of the plugin mirrors these results.]

UAD Empirical Labs Fatso linear analysis chart
UAD Empirical Labs Fatso linear analysis


UAD Empirical Labs Fatso harmonic analysis chart
UAD Empirical Labs Fatso harmonic analysis


Here are graphs using my two presets for the Fatso: Penny_BUS and Penny_CHANNEL.

I have the low end rolled off significantly and the manual explains why, and how to adjust this. I also have a hotter input which creates a bit more distortion/harmonics. You can make your own custom console sound using these setting. (If you have enough processing power!)

UAD Empirical Labs Fatso linear analysis chart for Penny Cool preset
UAD Empirical Labs Fatso linear analysis – BUSS and CHANNEL presets


UAD Empirical Labs Fatso harmonic analysis for the BUSS and CHANNEL preset
UAD Empirical Labs Fatso harmonic analysis – BUSS and CHANNEL presets


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