Circuit Rhythm features two audio inputs. These signals may be treated as either a stereo source or summed together as a mono source depending on where the signal is used.
All samples in Circuit Rhythm are mono, and so when recording the audio inputs into a sample slot, the signal will be summed to one mono source.
Otherwise, inputs are passed to the Grid FX as a stereo source. This is then passed on to the Master Filter before going to the outputs, all as a stereo signal.