rat with 3 couple of diode and possibility of sym asym

[Donniedarkoz]

hello I saw on the internet this pedal permits the combination of three pairs of diodes and the possibility of sym / asym. for the combination of the 3 you can use a switch 0n/0n/0n as follows in my design, I can not implement the possibility to add a diode for asymmetrical clipping think the pedal select a diode (asym) for different combination . can someone help me? the pedal in question is this: http://www.youtube.com/watch?v=R2Jmj21P78A here a picture of the interior
I can not use rotary switch does not have enough space ... : '(