The Express is an evolution of the F-series, and it's contour function is basically the same as the F-series, only they've added a knob to control the effectiveness of the EQ, and I'm willing to bet that it's the same basic circuit.
That EQ shape that I've worked out is not a guess-timate or the typical EQ shape, it's derived from looking at the circuit and mathematical equations.
Sling Blade said:
I read in my 550 manual that the Express is already scooped. It said that most Mesa users set their amps up with a scoop so they set the Express up this way right out of the box. I believe I read that if you roll your contour off (turn it down or to the left) You will get less mid range freq. making your guitar feel like it is easier to play. which is true. And the more you turn it up it adds more mids in return makes it feel like you need to play your guitar harder.
You've got it completely wrong.
When you roll the contour off, you get
more mids. The higher the contour setting, the more "scooped" the sound becomes, and if it makes your guitar easier to play, it's because it hides the nuances in your playing! (or masks the mistakes / lack of clean technique
)