Slimdub14 Keep in mind that the Ares is a 2 channel DAC and will only work with the main left and right channels. A DAC is a digital to analog converter. You use it to convert any digital sources such as the digital out put of a cd player (to bypass the built in one) or a bluray disc player, a computer or a streamer or server. Then connect the output (the RCA jacks) to any available input on your Marantz. Not a phono input though. Also be aware that your home theater system may not be able to take advantage of all the performance that the Denafrips has to offer.
Good luck!
Good luck!