The Airwindows compressor, malleable into many forms if you know how. Version 4 brings new functionality that has never existed in Pressure before: the stereo version (default for VST, and the Audio Unit that doesn’t specifically say ‘Mono’) uses a special linked mode based on diade bridges in hardware compressors. That’s not to say that it is ‘analog modeling’ because it isn’t. From the beginning, Pressure has been made out of a lucky algorithm with a particular organic, pleasing quality, and part of Pressure4 is knowing what to strip down, how to simplify that algorithm until it lets all the music through.