The EQ pop-up menu and the Amp-EQ Link button are near the top of the interface.
EQ parameters
EQ pop-up menu: Contains the following EQ models: British1, British2, American, and Modern. Each EQ model has unique tonal qualities that affect the way the Bass, Mids, and Treble knobs in the Amp section respond.
Amp-EQ Link button: Located between the Amp and EQ pop-up menus, links these pop-up menus so that when you change the amp model, the EQ model associated with that amp is loaded automatically.
Each amp model has a speaker and EQ model associated with it. The default combinations of amp, speaker, and EQ settings re-create a well-known guitar sound. You can combine any speaker or EQ model with any amp by turning off the two Link buttons.