This is a duplicate of the Big Muff but using a quad op amp instead of transistors. The idea of using op amps for the Muff gain stages has been around a long time, and I made my first version of this type of circuit in the late 1990s. About 18 months ago, I got out this old design and updated it and re-sized the board to fit in a 125B enclosure. In fact, I posted a picture in my Instagram of the bare board over a year ago. You can recognize it in the middle of 3 bare pc boards that I’m holding in one of the old pix.
Due to persistent medical problems, I have not yet fitted it into a box, though I did complete the pcb and prepare the enclosure. I hope to get it put together before long.
I have seen a number of similar designs recently based around the EHX Muff 2, and those circuits differ quite a lot from my old design. I believe that mine will sound more like a vintage Muff because of the way I carefully prepared each gain stage to duplicate the equivalent transistor stage.
