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.
Demo by Shwan Hatfield (EN)
Demo by Tim Cole (EN)