“The free plug-in Saturation Knob is a modeled output distortion that can be used anywhere you need some grit. Use it to fatten up bass lines, add some harmonics and shimmer to vocals, or simply destroy your drum loop.
How can I get it?
Saturation Knob is available for free! Simply sign in to your Softube/Gobbler account and click the ‘Get Your Free License’ button at the top of this page.
Then go to their Download page and install the Gobbler App, which is used to install their software. Sign in to the app using your Softube/Gobbler account and click the ‘Install’ button next to the Saturation Knob to install it. This will make it ready for use in your DAW.”
Source : softube.com