Expression Pedal compatability question: SY-1 pedal for controlling a CS50?


Hi all,
I happened to find an original Yamaha SY-1 expression pedal which looks virtually identical to the one used for the CS50 and CS80, and when peeking inside it seems as if it is also based around the same sort of circuitry as the CS80's swell pedal. According to the SY-1 product leaflet, its applications (i. e. controlling volume and filter) are the same.
Simple question: Can the SY-1 pedal be used with the CS50, or am I risking to damage the 50 when using the wrong type of pedal?
Thanks for any info more competent than what I already have.