The Mask Audio Civil Math is a "Civil War" Muff variant on the company's Black Math, which produces a more midrange-y tone with also rounder and bassier quality. https://www.youtube.com/watch?v=x472f3e6liw https://www.youtube.com/watch?v=Hqrvz337cQI https://www.youtube.com/watch?v=XtgQyWiF19I&t=51sClick on the title for more