Attack range = 50us to 50ms  ( 0.05 to 50 milliseconds )

Attack controls how quickly the gain reduction will begin after a signal has crossed the threshold. 

For example - when your guitar signal goes above where you set it to activate (threshold) it will take anywhere from 50us to 50 ms for it to compress the signal.

 

Release range =  50ms  to  1 second

Release controls how long it takes for the compressor to return to it’s level after the signal drops below the threshold.

For example - when your guitar signal goes below where you set it to activate (threshold) it will take anywhere from 50ms to 1sec for it to stop compressing the signal.

 

*Threshold is set as a ratio that determines how much gain reduction will be applied. *

On this pedal you can choose from the following ratios:    2:1   4:1   10:1 



* If any of this is confusing – which it can be! - you can check out these links:


Empress Compressor controls video


Great explanation of compression pedals and how they workhe's like, the Rocky of guitar lessons.


Always a great resource for practical pedal usage though sometimes a little long-winded :)