Many years ago I was sent some pictures of Frank Zappa's, modified, late 1970's Big Muff™. The mods made to the pedal give it a very smooth, warm sound on the bass side but allows a little brightness on the high strings. They also reduce the gain of the pedal making it more of a low to medium overdrive/fuzz mix. The pedal yields a full-bodied, smooth, low-end and sweet highs with a little bite on lead notes. In 2016 I made a very limited run of the pedal and called it the Utility Muffin, named after Frank Zappa's recording studio, the Utility Muffin Research Kitchen.