Axis Supersport MM90 Piezo – controls diagram?

Hi guys and gals, I’ve just picked up an old Axis Supersport MM90 with the Piezo and I’ve forgotten how the output jacks work. Will a mono cable in the mix output work to sum both mag/piezo or is a stereo cable necessary? I’m sure when I had one years ago this is how I used it but getting a bit of memory fog.
I’m actually not getting any piezo output from either output using a mono cable which is why I’m asking.
Thx