Well, I have the Mooer versions (i.e. Black Secret and Blues Crab). The blues Crab is my to go, basic tone with a slight overdriven tope with nice overtones and controlled low end (I play a JTM45 with KT66s). By comparison, the Black Secret offers a slightly different type of drive: more gain on tap and quite a different voicing. But recently I have started stacking both with some good results. Anybody has combined these two circuits?