Wet:  A Wet signal is the sound after it passes through the chain of effects (pedals).  The opposite of this is a Dry signal (no effects).  A knob that combines the Wet/Dry signal is commonly referred to as a Mix or Wet/Dry knob.  This gets more complicated when setting up a Wet/Dry sound through multiple amplifiers.


Video Explanations:

Short Video: Wet/Dry Rig Explained in Under 5 Minutes

Long Video: Wet-Dry & Wet-Dry-Wet Amp & FX Setups Explained – That Pedal Show


Fifty Favorite Effect Pedals for Sale: