The FX tab allows you to add up to four effects to either kit A or kit B. The effects are applied across the entire signal (for adding FX to individual instruments, please see the shaper FX here).
The left column is where you add FX to Kit A (represented in blue), the right for Kit B (represented with purple), and the middle column allows you to add effects to the entire combined signal of Kit A and Kit B.
The small blue and purple pipes represent the flow of signal and order that FX are applied, starting in the top left and right, and finishing in the middle at the bottom.
The best way to discover what each effect does is to simply load it up and experiment! A full list of effects is available here .
Adding and controlling an effect
If no effect is assigned to a knob it is blank, whereas a knob with an effect assigned to it will have two dials and a small symbol in the middle representing the FX category.
In order to add an effect to a blank knob, simply click it once, and you will be presented with a small menu of five effects categories. Click on any of these to see a list of effects in that category, and click an effect to add it.
In order to remove an effect, simply right click it and then hit "Set FX > No Effect".
Eight little LEDs
Under the FX A and B chain you can see eight little LEDs. They represent the "Route to FX" Button of the Mix Page. You can turn them on and off to route the track into the FX chain.