Pan/Fade

Linear Voltage Controller Panner or Cross Fader

Pan/Fade consists of two linear VCA's that can be configured for either voltage controlled panning or vc crossfading. Ring Modulation type effects can be obtained through VC Crossfading at audiorates.
When I was working on the development of the Active Processor module/PCB’s, the original schematic made it quite obvious you could use the PCB in many ways. I wanted to make the most of the board and made it able to either VC Crossfade or VC Pan.
When the mode switch is in the Pan position, Input 1 is active (input 2 will be ignored) and the VC Pan input will send the input to either of the two outputs. When the mode switch is in the Fade Position, Inputs one and two are active, but only output 1 will be functional, allowing the module to cross fade under voltage control.

https://www.low-gain.com/shop/p/lge201p