It's an ex-madbean project - go visit his f**king brilliant site here for loads of DIY goodness; http://www.madbeanpedals.com
Here is a schematic for reference:
You'll notice it's his "signature" Super Hard On circuit (Which is a great building block!) cascaded into one another. The tone control is a derivative of the classic Big Muff setup (But the actual values are nicked from the well known DIY project the "Brown Sound in a Box II" (BSIAB for short). Interesting really.
Here's your demo video: