David – Which pot are you naming as the “Distortion” pot? And what specific taper and blue of the Gain pot (P1) are you using? It works best if it’s a linear taper. (B500K)
I’m only guessing that you named the Dr Rock “Gain” pot as “Distortion”.
Also, what are the voltages at supply, IC1 (all pins) and Q1 (all 3 pins) please? Photos?