Up to two footswitches (BOSS FS-5U) can be used to turn the effects on and off in the AD-5.
When using one FS-5U and a standard instrument (or Guitar) cable, the Chorus can be switched on and off.
With two FS-5U's and an "Stereo insert cable" (1/4" Stereo - two Mono L/R 1/4" cable), the Chorus and Reverb can each be turned On and Off separately.