Need reco for IC to tame a bit of

Recently added a very simple and minimal 2 channel set-up in a dedicated HT/listening room. The room is treated, and the results have been astonishingly good, and frankly better than much more expensive gear I have heard over the years. The system is very revealing, and now that I have lived with it a while, I would like to try to tame a bit of upper mid-range/treble glaring so that it is a bit less fatiguing at higher volumes. All components were selected with an emphasis on transparency and soundstage, so I am not surprised that the system is a touch bright.

The system is thus: Cary 303/200 CDP playing direct through Harmonic Tech Silway 2 balanced interconnects into a Spectron Musician II Class D amplifier. Speaker cables are a DH Labs Q-10 "Remote Sense" design (making the speaker cable and speaker part of the digital feedback loop)and the speakers are Totem Forests. Ideally I can leave everything else alone and try some different interconnects as a way to relax things a bit. Suggestions?