I've built a DOD OD 250, the MXR distortion Plus, Devi Ever Sodameiser, and a Triangle Muff. The Muff was on a purchased PCB, the rest are veroboard. I'd like to build another OD, maybe something to replace my tube screamer. What's a good choice here? Could the OD 250/ Distortion + be modified for a mid boost, or is there another circuit I should be looking at? I'd prefer to build something with the components I've got, but certainly can make an order if I need a particular chip, or different value caps.