How do I use Pre Out connections? April 09, 2024 11:26 The 'Pre Out' outputs are for use when connecting to a power amplifier or active subwoofer. Please see the diagram below. Related articles How do I use EVO with an external power amplifier? What is Preamp mode? FIXED LINE-OUT MODE Is there a crossover frequency applied to the Sub Out of EVO 75 & 150? How do I use speaker B connections? Can I use the CXA61/81/81 Mk II with pre out only to an external amp without speakers connected?