Theil/Classe 6, and listener fatigue

I owned Thiels for over ten years and found them to be amongst the least fatiguing speakers around. I believe this is a function of sheer accuracy. They are detailed and therefore some people who seldom listen to live music call them "bright". I suggest you try a different CD player first.

I believe there is nothing worse than trying to "tone-down" the Thiels with some "colorful" tube gear. That will simply spoil the Thiel's crispness and other strong points unless you spend thousands and thousands of dollars in a super tube amp. There are a number of appropriate ss amps that work fine with Thiels, including Classe, Levinson, and also Marsh Sound Designs. Alas, it could be that you are simply in the camp which believes the Thiels are bright and if that's the case nothing will really change your mind, in my experience. If so, my best advice would be to sell the Thiels and get something else. Although perhaps before doing so you may want to go to a couple of live music events to make sure what you are hearing is not the way real life sounds.