Reference:Tweaking Tones
Gate
The Gate effect helps eliminate unwanted noise when you’re not playing, and can be especially valuable when using high gain sounds. Like a security gate, it’s supposed to
5•12 quickly open to pass the things that you want, and then swing closed to keep out the things that you don’t want.
Thresh – determines how loud your playing has to be to open the gate. More negative numbers (where the knob is near its
Decay – determines how fast the gate will swing closed. Like a gate in the real world, a fast decay means the gate might catch your trailing foot as you pass through – in this case, that means the gate will chop off the decay of your notes. And a slow decay means that as the gate swings slowly closed behind you, someone might have time to slip through – in this case, that would be the unwanted noise that you hear as your notes decay. You’ll have to experiment with the Decay to get just the right happy medium for your particular guitar, playing style, and sound settings.