How do I connect a RCA / phone plug to the balanced input of the digital crossover?
If you want to use a single-ended signal RCA / chinch connector, because your preamp has this connector type you simply short the inverting input (pad labelled 3) of balanced input of digital crossover to the AGND pad (analogue ground labelled 1). The inner core connects to non inverting input (pad labelled 2) and the screen wire connects to the AGND.