Trade in the marantz. You have a lot of wasted technology shoved into a box that you want for stereo listening. It's not a bad pre-amp, it's just that it is designed for theater. Sell the Marantz and get something designed for stereo listening. With the big boom in surround sound, you should be able to get a nice deal on a good used stereo piece like classe, audible illusions, CJ....
By the way, to test your d/a, try going digital from the cd to the marantz and listen to the differences?
By the way, to test your d/a, try going digital from the cd to the marantz and listen to the differences?