Need some advice please. Looking for best quality setup. Currently have a mac mini and iphone which connects to a Yamaha WXC-50 music streamer. Have it both cat6 wired from the mini and wifi over musiccast system from the phone. Then from the rca pre-outs of the Yamaha to a pair of powered speakers. Sounds pretty good! Now, I am going to add a quality pair of powered speakers (Dynaudio Xeo 6's), through a Dynaudio Connect box. So, there are a number of ways to do this I think, but which is best? I think the pre-amp is fairly well regarded in the Yamaha, so would optical bypass this? I will try to attach the manuals if I can. Also, I'm considering adding an external dac. How would this fit in? Just want to make sure I've got all I need when the speakers come. All advice gratefully received.