Does anyone know the easiest way to take a clean mixed sound output from the Soundcraft Si Performer 1 digital mixer into an ATEM mini / extreme? Plug into the headphone monitor?
your best bet is to use a Radial J-ISO. This will convert your XLR +4dB balanced left/right signals from the mixer to - 10 dB unbalanced 1/8 inch or phono for the ATEM.
Use a Dual XLR to 3.5mm stereo cable between the mixer and the ATEM.
You would need to plug the 2 XLR in 2 XLR analogue outputs (2 out of the 16) on the back of the unit and then plug the 3.5mm male stereo cable end into the ATEM mini/extreme and make sure the audio in is in line in mode for that port on the ATEM.
Here is an example of the cable you need:
You will have to make sure the audio that you need for the ATEM is routed in the Soundcraft mixer to the outputs you plugged this cable into on the back of the Soundcraft mixer.