Yes – you can connect up to 3 extra switches to the Aux Switch jack on the rear panel which can be programmed in many useful ways. See the manual for more info.
We use a Digitech FS300 footswitch which gives you the 3 switches and a jack lead.
There is a limit to what you can usefully do with the 3 switches on the box, so the use of the AUX switch can be helpful to extend the functionality.
