What is unique about the Pressure Valve Pedal:

Keeping with the theme of the Jawbreaker; what is handled differently than other pedals is the  attack  and the timbre of your original guitar tone.

Most compressors compress the signal as a whole and because the attack is the most dynamic (the most drop in amplitude after the attack) it gets the most compression which results in a thuddy sounding attack.  To work around this compressors often employ an "Attack" control which is basically a delay of when the compression kicks in.  This works to some extent, but still tends to sound a bit unnatural and it's very difficult to find an attack setting that works for all situations.

The Pressure Valve treats the attack separately and applies the least compression to that initial portion of the note decay.  What you get is a very natural sound that has very interactive feel.  In fact you really feel the compression more than hear it.  Notes attacked hard still have the unique timbre and aggression while giving you complete control of how much actual output volume swing you want from the dynamic range of your playing.

It's especially great at emphasizing those in-between positions of a Strat and the middle position of a Les Paul and sounds great for some Tele "Chicken Pickin"

The Decay control allows for either a fast decay (great for that Chicken Pickin sound) or a slow decay (Great for sustaining the notes)