Lamm ML2.1 voltage selection

Hello all,

I am trying to find information about how voltage selection works in the Lamm ML2.1 amp. I know you may need to change the fuse, when switching from 100/120 to 220/230/240 or vice versa. But contrary to e.g. the L2 preamp, you don't have multiple fuse slots (putting the fuse in the slot corresponding to your voltage).

It seems you need to fiddle with the red-capped leads that can be seen at the bottom left of the PCB:

However I could not find details about this. If anyone has already done it please let me know.

Any clue would be highly appreciated!