The UAD Empirical Labs FATSO is Universal Audio's model of the Full Analog Tape Simulator and Optimizer, built with original hardware designer Dave Derr. As of October 13, 2026 it runs as a UAD native plugin on macOS and Windows, so it loads in any DAW without an Apollo interface or UAD-2 accelerator.
It is a character box rather than a tape machine. Warmth is high-frequency saturation and soft limiting that tames harsh highs, Tranny adds transformer and tape-head saturation for weight, and the compression offers four modes: Buss, G.P., Tracking and Spank. The plugin ships as two linked versions, the quick FATSO Jr and the deeper FATSO Sr, which adds a Tranny control, sidechain filtering and adjustable compression times.
Against its alternatives, FATSO is the saturation-plus-compression glue box. Soundtoys Decapitator is pure analog-style distortion with no dynamics, the UAD Ampex ATR-102 is a dedicated reel-to-reel tape machine, and the free Chow Tape Model is a budget starting point. Choose FATSO when you want warmth and compression in one move. Our FATSO native first look has the full spec and comparison tables.