james david low

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Custom Neunaber ExP (3 Switches and other variations)

I wrote a previous post about my custom Neunaber ExP controller that uses a counter to switch between the 4 effects with just a single button.

3 Switches
I’ve had a few requests about how to do it with just switches. I’ve drawn up a circuit, but don’t have time to build it, so I can’t be 100% sure it will work.


– Neunaber don’t cover warranty for custom ExP controllers, I can’t be held responsible if you break your pedal.
– If you only want 2 effects, you can leave off the 3rd LED and switch
– The logic of the switching in this configuration is more like 2 banks of 2 effects with 2 presets each. Switch 3 selects between bank 1 (effects 1/2) and bank 2 (effects (3/4). Switch 2 selects between either effect 1 and 2 or effect 3 and 4 depending on the position of switch 3.

Common Anode
Another variation depends on the the type of multi-colored LED you use. Some have common cathodes, some have common anodes. You have to connect the common pin to the rail, and the individual coloured pins to E0/E1 because connecting the common pin would join E0 to E1 which you don’t want to do.


This also changes which colors indicate which effect:

Q1 Q0 Effect LED
0 0 4 Orange
0 1 3 Red
1 0 2 Green
1 1 1 (off)