I wish to describe some things about the RCA output. The common on coaxial is 75Ohm , unfortunatly RCA connectors and RCA cables usually are not capable of 75Ohm due to geometry/physics . We spoke to some brands of DACs and some of them currently carried out 50Ohm impedance (given https://pingdirapp52.directoryup.com/top-level-category/displays-holders