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Customer Reviews 233 Reviews

4.83 out of 5 stars

by D. Thompson (9/25/2015):

This plugin adds a kind of blanket over my guitar buss. I just love it, I do a lot of… Read more

205 Reviews
19 Reviews
7 Reviews
1 Reviews
1 Reviews

FATSO™ Jr./Sr. Tape Sim. & Compressor Plug-In

The Empirical Labs EL7 FATSO’s ingenious design and creative feature set gives users the wonderfully warm and pleasing sound of magnetic recording tape, class A transformers, and tube circuits. Endorsed and scrutinized for accuracy by designer Dave Derr of Empirical Labs, Universal Audio has painstakingly recreated the FATSO Jr. in this highly anticipated UAD Powered Plug-In, capturing the sonic nuances of the original hardware. Specifically, the FATSO is designed to musically integrate frequencies and transients — and increase the apparent volume of your source material — in the same way classic analog equipment does.

Legendary engineers including Ed Cherney, Al Schmitt, and Brendan O'Brien, and artists including Paul McCartney, Trent Reznor, Blackalicious, Jack Johnson, and Avril Lavigne, have helped make the EL7 FATSO Jr. a modern studio standard. As part of the FATSO Powered Plug-In, UA has also worked closely with Dave Derr to model his never-before-available original concept of the FATSO, the FATSO Sr., at no additional charge.

The FATSO's Input control gives the ability to dial in harmonic generation/distortion while “Tranny” and “Warmth” allow the user to dial in just the right amount of tape and tube tone. The FATSO also operates as a highly versatile compressor, and is useful for mixing and stereo buss compression. From tame to trashed, the FATSO offers a wide palette of possibilities for adding analog character and cohesiveness to your DAW tracks. Adding Dave Derr's own custom mods to turn the original FATSO into an unbelievable tonal-shaping powerhouse, the FATSO Sr. offers a “Tranny” saturation control, sidechain filtering and deeper compression parameters including Threshold, Attack and Release. These special FATSO Sr. mods are only available with the UAD Powered Plug-In version of this essential studio tool.




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  • Jono Buchanan

    (Future Music UK)

    "UAD owners are going to flock to the FATSO plug-in in huge numbers. As they should ... this processor is irresistible."

    Ivan Barias

    (Musiq Soulchild)

    "The FATSO is a 'must own' UAD plug-in. I love it on the kick & bass tracks. It's also amazing in the master buss chain."

    Young Guru


    “These are the best plug-ins I have ever used. God bless you for the FATSO Jr./Sr.”

    Justin Niebank

    (Taylor Swift, Rascal Flatts)

    “That FATSO plug knocks my socks off, period. I'm always finding new things to use the FATSO on"

    Christopher "Stone" Garrett

    (Thievery Corporation)

    “I totally love a Fatso Sr. on the overhead mic, and we set it to obliterate or fry…A lot of times I'll use the same settings from the hardware on the UAD version."

  • Billy Bush


    “The [UAD] FATSO is my favorite tool for warming up guitars. It brings out some of the harmonic content that isn’t necessarily obvious when recorded digitally.”

    The Glitch Mob

    "The Fatso is our go-to secret weapon for softening and warming up abrasive soft synths.”

    Paul Moak

    (Third Day, Matthew Mayfield)

    "The FATSO underneath the primary voice chain adds a cool sonic character that brings the voice out."


    (Computer Music)

    "So, what's FATSO Jr. good for? Unsurprisingly, fattening snares and adding low-mid punch to kicks proved successful."


    (Computer Music)

    "Overall, you should buy FATSO for its sonic footprint (from a proven hardware unit) and its excellent custom upgrade FATSO Sr."

  • Reviewer


    "You can't go wrong with UA's plugs, and these three [EMT 250, FATSO and Trident A-Range EQ] are no exception."



    "FATSO is a 'magic wonder box', and again, UA has nailed what the original is all about—but also gone further, by including a FATSO Sr."



    "Granted this is Universal Audio's forte, but even so, this [FATSO] is a very impressive plug-in."



    "Anyone who's a fan of 'the analog sound' but uses digital because of cost and convenience will welcome what FATSO brings to tracks."

    Jacquire King

    (Norah Jones, Tom Waits)

    "And the FATSO Sr. That’s the [FATSO jr.] companion plug-in. Yeah, that is super, super cool."

  • Elliot Mazer

    (Neil Young)

    "FATSO is just that ... It is amazing that it can make something sound warmer and bigger and more present at the same time."

    DJ Richard Devine

    "When you need something to really punch but still have that warmth, the UA FATSO plug-in is the weapon of choice."

    Dean Coleman

    “The [UAD] FATSO plug-in really brings back the bottom-end warmth to a vocal that's lost it's way.”

    Garrett Haines

    (Tape Op Magazine)

    "Should mix engineers buy this [Manley Massive Passive] plug-in? YES. If they don’t have a UAD-2, should they buy one just for this plug-in? YES. You’re also going to want a license for the FATSO and Cooper Time Cube as well."

    Jono Buchanan

    (Future Music UK)

    "If you hanker for tape-like warmth, with an irresistibly wide and rounded sound, this [FATSO plug-in] you'll love."

  • Ed MacFarlane

    (Friendly Fires)

    "I use the FATSO plug-in as a buss-compressor ... I really like what it does – it can change the timbre of the drum kit."

    Paul White

    (Sound On Sound)

    "[FATSO] makes a fabulous bus compressor for adding a touch of analog magic and density to a mix ..."

    Paul White

    (Sound On Sound)

    "[FATSO is] Perfect for making aggrssive things even more aggressive! ... Definitely one to have on your team, if you can."

    Paul White

    (Sound On Sound)

    "[Cooper Time Cube, EMT 250, or FATSO] ... for the real vintage character, I don't think UA have any rivals at the moment."

    Elliot Mazer

    (Neil Young)

    "FATSO is a fantastic multi-use plug. I used it on some toms the other day and kaboom!"

  • Jeff Balding

    (Amy Grant, Faith Hill)

    “I'm knocked out by the FATSO! It sounds absolutely amazing!”

    Roy Davis Jr.

    "[The FATSO plug-ins] can breathe life back into your digital system!!! I'm riding with UAD all the way!!!"

    Charlie Clouser

    (NIN, "Saw" Soundtracks)

    "I have to say, the FATSO sounds better than any plug-in I've ever heard. I'm utterly amazed."

    Roy Davis Jr.

    "UAD FATSO is my #1 choice for compression on drums or vocals it can give you that upfront presence that you need with alot of warmth."

    Charles Scott

    (Star Trek, Hung, Fringe)

    "The new FATSO Jr/Sr [plug-in] is amazing. It may be the only dynamics module you need — it’s that versatile."

User Ratings

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Average Rating (233 Reviews)
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    Useful plugin
    by D. Thompson(Friday 25 September, 2015)

    This plugin adds a kind of blanket over my guitar buss. I just love it, I do a lot of electronic mayhem, also very heavy metal, I am not a metalhead - I just like to express my stress through EMG 81's and an ESP now and again. And this bad boy adds the cover I feel is needed when the time is… Read More

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    by A. Gamez(Tuesday 22 September, 2015)

    This thing is amazing! Love in on snare and electric guitars. Gives you a fatness that only tape lovers would know. If you mix in the box, or even on outboard gear, this plugin will always make you happy and sound freaking great. MUST HAVE! Read More

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    As expected
    by E. Eagle(Wednesday 16 September, 2015)

    As a Distressor owner, I am happy to report that I am loving the UAD Fatso. Obviously different but even though I've never used a hardware Fatso I find the sound and response familiar. Really great! Read More

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    I love love love this !!!!
    by H. Gu(Tuesday 15 September, 2015)

    It's awesome this is my best weapon!!! Read More

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    • 5 Star
    by D. Range(Tuesday 15 September, 2015)



  • Armin van Buuren

    In the world of dance music, few have amassed as stellar a resume as Armin van Buuren. Here, he details how UAD plug-ins help him to entrance audiences night after night. Read More

    Jacquire King

    Jacquire King (Of Monsters and Men, Norah Jones, Modest Mouse) shows how he used the Apollo interface and UAD plug-ins to track Robert Ellis' band on a live rendition of the track, "Good Intentions."… Read More

    Charlie Andrew

    As the artful studio helmsman behind British folk-hop sensations Alt- J — and their 2012 Mercury Prize-winning album, An Awesome Wave — producer Charlie Andrew found himself the recipient of Britain’s Breakthrough Producer of the Year Award for 2013. Read More

  • Tom Salta

    Renowned video game composer Tom Salta details how he uses UAD plug-ins to craft award-winning scores. Read More

    Diplo on crafting mega-hits with UAD plug-ins.

    One of the most in-demand producers in music, Diplo has crafted hits for M.I.A., Snoop Lion, and Beyoncé. Read More

    Neal Cappellino on mixing Brad Paisley

    Grammy-winning engineer Neal Cappellino has recorded and mixed hits for Nashville's biggest stars. Read More

  • Noel Hogan's Production Renaissance

    Noel Hogan shares his Cranberries history and his current recording and production methods. Read More

    Top Engineers Top "Desert Island" Plug-Ins

    If you were stuck on a desert island with your recording studio, what UAD plug-ins could you not live without?… Read More

    R&B Engineer Tremaine Williams

    Tremaine reflects on how UAD Powered Plug-Ins have helped to further his quest for audio perfection. Read More

  • Producer/Engineer Billy Bush Mixes Garbage

    Bush uses UA tools extensively while sculpting the band’s edgy guitars, driving percussion grooves, and glistening electronics. Read More

    Rik Simpson

    Simpson has worked on three of Coldplay's albums, including Mylo Xyloto, which he co-produced, engineered, and helped mix. Read More

    Phil Tan

    With more than 24 #1 Billboard Hot 100 hits, 3 Grammys®, and nearly 300 album credits, there are few engineers that can touch Phil Tan’s recent track record. Read More


Features & Specs

FATSO™ Jr. /Sr. Analog Tape Simulator & Compressor Plug-In


  • Recreates the warm, musical qualities of magnetic recording tape, tubes, and class A transformers
  • Licensed and endorsed by Empirical Labs, created by Universal Audio
  • Clipping, Warmth, Tranny and Compression Select allow for a wide variety of analog tonal shaping possibilities
  • Additional UAD Powered Plug-In exclusive, FATSO Sr., provides original concept developed by Empirical Labs’ Dave Derr
  • FATSO Sr. features include Tranny Saturation, Sidechain Filtering plus Threshold, Attack and Release
  • Stereo or Mono operation with independent Left/Right controls
  • Requires a UAD-2 DSP Accelerator Card or Apollo Interface available from authorized dealers worldwide


  • Input Gain operates as processor threshold and allows for clipping distortion
  • Output Gain operates as makeup gain/gain reduction
  • Warmth circuit and cycling button offers seven degrees of saturation simulating the softening of the high frequencies that occurs with analog tape
  • Tranny circuit adds frequency "rounding," low order harmonic clipping, intermodular distortion and transient clipping
  • Tranny/Bypass cycling button allows for Tranny enable/disable and independent channel Bypass of all processing
  • FATSO Comp cycling button offers seven compression options:
    • Buss - Slow attack, fast release, soft knee buss compression
    • G.P./General Purpose - Medium attack, slow release, transparent compression
    • Tracking Compressor - Fast attack, medium release “1176-type” compression/limiting
    • SPANK - “SSL talkback-type” aggressive limiting, can also be combined with Buss, G.P. or Tracking
  • Warmth and Compression metering via horizontal LED meters
  • Distortion metering via the "0 VU" yellow LED light indicating 1% THD, red "Pinned" LED indicating 5% THD or more
  • Link Compress links or unlinks compressor sidechain between Channels 1 and 2
  • Link Controls links or unlinks Ch 1 and 2 controls for ease of use in stereo operation
  • Processing can be bypassed globally via the Power switch for comparison to the original unprocessed signal


  • All of the FATSO Jr. controls plus…
  • Threshold Lvl knob adjusts compressor threshold
  • Tranny Lvl knob adjusts transformer saturation
  • HP Side Filter enables high pass filter in compression sidechain, selectable between 60, 120, 240, and 480Hz
  • Attack cycling button manually adjusts compressor attack time between 0.9, 10, 30, and 60ms
  • Release cycling button manually adjusts compressor release time between 0.05, 0.1, 0.2, and 0.5s


UAD Plug-Ins Manual

UAD System Manual

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