I believe it's your source. If you were to use the CDP as a transport and get a Perpetual Technologies P-3A DAC modified by Dan Wright and a good digital cable, this would add a lot of sweetness to the midrange and achieve better detal overall, not to mention better bass impact. I believe Dan sells them modified - SignatureII mods. I have one and It's superb - no glare.
Upper midrange glare prominence --
I am not sure this is a cabling issue. I have an Arcam Alpha 8R integrated which is warm, Paradigm Studio Reference 20 v.2 monitors and a Denon DCM370 (Burr-Brown). I have been spending a lot of time auditioning cables to counter the metal tweeters in the Paradigms--both speaker cable and interconnects. I have become aware of another problem--no matter what cables I listen to--it seems like voice and guitar are whacking me on the head as I listen. Too prominent. What are counter-measures for upper midrange problems like this?