Why am I experiencing listener's fatigue?

My system is as follows. All thoughts and opinions are welcomed and appreciated.

B&w nautilus 805 speakers with jumpers ,
tweeter/driver grilles removed/tweeters at ear height
Cardas cross single wire speaker cables
Cardas golden reference interconnect
cardas golden power cord
Monster hts 2000 power bar/conditioner
Manley stingray (2 mullard 12at7's and 8 Ei el84's)
sony xa 777es cd/sacd player
7 inch diameter by 18 inches high concrete speaker
stands
blu tac between the speakers and stands
Particle board equipment stand
14 inch (1/4 filled)innertube under the sony
No DIY or professional room treatments at the moment
Stock sony power cord