The Volume is standard 40 you can change it if you like.
By Preset, you have the ability to set for:
Disabled, Default, Hard, Hard 2, Hard Commercial, Medium, Soft and Soft 2.
With Custom Values you can set your own preferred compression.
10 Band Equalizer.
You can set it up as you like
Automatic Gain Control
Preset can be on:
Hard, medium and soft.
Automatic gain control (AGC) is a technique found in many electronic devices. The average or peak output signal level is used to adjust the gain to a suitable level.
Tip from Marius.
I don't like high ratio on compressors because it flattens the dynamics.
Also I get much cleaner sound when disabling AGC and set the compressor a bit more aggressive.
But I guess that it depends a lot on what type of music you play.