Going from
this schematic, you can see the three-position switch labeled "CLIP" (under the first op-amp). From the "Clipping Switch" notes:
The clipping switch allows you select between different sets of diodes.
The left position of the toggle switch is the stock MT-10 clipping arrangement, which has two silicon diodes in each direction. The right position of the toggle is one diodes in each direction, as in the Tube Screamer—a lower clipping threshold with a more compressed sound. The center position leaves only the LEDs for a more dynamic and transparent tone.
Emphasis mine. Per the schematic, you want to jumper switch pins 2 and 3.
If I'm thinking this through correctly, that means you should jumper the middle and left holes of the clipping switch, if you are looking at the face of the PCB where the components go. (The switch and pots get soldered to the "back" of the board compared, while all the rest of the components get soldered to the "front"; so when looking at the front of the board, switch to the
right means four total clipping diodes, and the switch in that position means the
left two solder holes are jumpered.)
You can also leave out the clipped LEDs (D8 and D9), and the single clipping diodes (D6 and D7). If you bridge the switch correclty, it won't matter if they are in there or not, but you might as well leave them out.
You could also opt to build the
PedalPCB Oxide Distortion which does not have the clipping switch (and should be true to the original Mostortion).
