Yes, a stereo input is possible. It sounds like you have tried the correct things so far.
What exactly is the stereo input cable you are using? You need to use a TRS cable for the stereo input to work properly.
What is the stereo source you are sending to the TriceraChorus.
I’m not sure what you mean by “two mono cables” verses “one stereo cable” for the output. The stereo output of the TriceraChorus uses two TS 1/4 mono jacks.
To sum up how to connect in stereo:
- Set input dipswitch to stereo
- Connect a TRS 1/4 stereo cable to the input. You will need to feed it a stereo signal.
- Connect two TS 1/4 mono cables to the outputs, and connect those to your amps/monitors.
Let me know if that helps.