The Mesa Mark V foot switch makes it easy for yous to introduce a range of effects into your music using only a foot. The foot switch comes with eight buttons: a reverberation button, an equalizer button, an effects button, a mute button, three channel buttons and a solo button, which, when pressed, silences all other instruments so only the guitar can be heard.
The Mesa Mark V foot switch comes equipped with four 1/4-inch external switching phono jacks that allow you to control some of the Mesa Mark V foot switch functions remotely using a master switcher. The functions that may be controlled in this way are the three channels, the equalizer and the solo functions. The owner's manual explicitly suggests using a MIDI foot controller for this purpose.
Using a MIDI foot controller allows bands to use the Mesa Mark V as part of a MIDI rig where both the amplifier and effects settings are stored under a MIDI Program number. Note that the four external switching jacks use the standard tip-to-ground latching logic, and not momentary logic. This is true of most master switching devices.
Note that the external switching jacks override the Mark V's own foot controller. This means that if you plug in a MIDI foot controller, you do not have to worry about accidentally changing settings using the basic foot controller that comes with the unit. Once a function has been turned on using a device plugged into an external switching jack, it cannot be controlled or turned off until the logic is reversed at the switch port.