Big Muff PI Tone Stack Mod
Just as my last post, this is a Big Muff tone stack but with Beavis Audio’s added “body” control. Here is some info
The indomitable Jack Orman (www.muzique.com) has researched the Big Muff Tone control and suggested various improvements. One of these improvements is to add a Body pot that provides more control over the response of the circuit. This version uses a 3.3k ohm resistor in place of the stock 22k value, and adds a 25k pot to ground. This provide you with a tone control that can handle both flat and “scooped” frequency response.
Here is the project document.