The MITs will definitely soften the high end and I believe its worth a try before changing the amp. My son is using an Aragon 8008st and AR LS3 preamp with Thiel 2.2s also went to the MIT MH 750s with good results (took that bright edge right off), although the 2.2 are not nearly as bright as the 2.3s and IMHO a better sounding speaker. A tube preamp will make the most difference, the MITs just completes the package. I have not changed CD players, currently using a Micromega stage 2 and 6 but of the ones I tried none made much of a difference to control the brightness. Your other option is to sell the Thiels and replace them with speakera that are warmer. I listen mostly to Jazz, Accoustic, and some Rock, the Thiels if not matched right will not even come close to what certain instruments should sound like. Example listen to Ken Navarro, with the Thiels you would run from the room in pain. Get it right and he is there with you. Hope this helps.