Thanks guys. The only reason I hesitate to list all components is that over the years in this hobby, I believe I know the character of each component I own and how placement of everything (all on isolation devices), cables- pcs (Shunyata) ics (Stealth Indra), etc. impact the sound. Since I have tested many items and changed the system over the years a number of times--all to work the synergies to my liking, I do not want to run a long thread in which I get numerous suggestions (try this cable, that isolation device, move the speakers)--all of which have been done too numerous times to mention prior to getting this amp and a few times after. So, with that in mind, I wanted to know if this trait was part of the break in process so I don't go crazy making adjustments and then find that the amp will become more relaxed and less shrill on these items over time causing me to readjust. As this is the only change in my system in the past year and I have had other amps that did not exhibit these traits including most recently the McIntosh MC2102 (which is smoother and rounder but less neutral and transparent than the REF 110), the first question is-did my past amps mask some thinness in the average cd and badly recorded records that the REF 110 reveals such that I am now hearing it. I believe this to be the case. Now as for the new found issue, will this character be somewhat ameliorated by the mere passage of time with the REF 110? I believe from Mickey sg' response that I must wait about 300 hours to pass judgment. Rest assured if the problem does not go away, I will be back with hat in hand and an examination of other components and synergies will ensue. Are there other ARC amp owners who agree with Mickey sg' s opinion?