Why do my new Transparent cables make my system sound muffled?

My system is a Rotel 1590 amp, B&W 804S speakers, a Marantz SR8500 AV receiver used solely as a pre-amp in pure direct mode, and an Integra dbs 50.3 Blue Ray/CD player.  My speaker cables are QED XT40s, and I use two sets for each speaker to biwire the B&Ws using the dual speaker connecting posts of the Rotel amp, one cable set going to the bottom and one to the top connections for each speaker. 

Based on all the reviews I have read, and I admit, reputation, I bought some Transparent Musiclink Plus cables to replace my Audioquest Evergreen and fairly high-end Monster cables. Before I installed the Transparent cables, my system had incredible mid-range and highs, and tight, deep, fast bass. The 350 watts per channel of the Rotel amp really make the 804s work, I think the way they are meant to. (Frankly, anything I tried in the 200 watt range just did not seem to really drive the 804s.)  But, the system had just a tinge of harshness or distortion when multiple voices were laid over. For example, Lorde’s Melodrama, which is a great CD for testing, I think, sounded amazing, but for just a few places where I could hear a little fuzziness when her voice tracks were laid over each other. All else, especially the piano and bass, sounded simply perfect, to my ears. After installing the Transparent cables, I could definitely hear each individual voice in multiple-track voice sections, with no more of that distortion or fuzziness. But, the bass became muddy, warm, less punchy, and seemed to spill over into the mid-range. And, the mid-range became less clear, present, and realistic sounding. The voices, which were more "in your face" before, now seem more in the background with more accentuation in the lower mid-range than before also.

Honestly, I am disappointed. I would appreciate any advice I can be given on whether this may be how the Transparent cables are interacting with my system, or whether I should just sell them and try different cables. Yes, the Rotel sound is a bit "brighter" than some. I actually really like that about it. But, I don’t want any harshness either. The Transparent cables did not just remove the brightness; they seem to have made the whole system sound muddy, for lack of a better description.

In a few days, my new Rotel RC-1580 stereo pre-amp arrives. I am hoping that will open things up again. But, I have a hard time imagining it will completely undo the muffled sound I am getting right now with these cables. I have the Transparent cables connecting the Blue Ray/CD player to the pre-amp and the pre-amp to the amp.  Once I get the new pre-amp going well, I plan to get back into Vinyl.  Damn my ex-wife for dumping my old record collection.  It would be worth many thousands now.  Thanks.