The X-FADE/GATE is an audio/CV crossfader with a built in gate (VCA).
This module features CV over the crossfade between channel 1 and channel 2 along with a manual parameter to set an initial crossfade setting.
CV on the overall volume/attenuation is also a key feature with a manual control to set the initial gain setting.
This module is AC/DC coupled allowing it to process audio and cv signals. You can select AC or DC coupling with the onboard switch.
LM13700 IC's can be found HERE