Audio Research Ref 110

For sake of clarity, this problem does not manifest itself on well recorded cds or vinyl, but on average and below average quality recordings and on some sacds. Thus, I suspect junk in- junk out. That said, what will break in bring?

I would agree with the junk in junk out. I spent a lot of time auditioning the Ref 110 when I was amp shopping and found it to be very neutral and revealing, with perhaps a bit of dryness in the upper mid range, it could be heard as thin. I think however that it was perhaps the speakers I was hearing and that the amp did not forgive, (hide), poorly recorded music.

Preamp? Source? Cables? Speaker?

While I appreciate that everything is system dependent, my question is, for those of you who have broken in the REF series amps, is this characteristic inherent in the break in process?

As far as I know, an amp does not make sounds without a little help. A power cord can make an amp sound quite different. If you had enough love of music to purchase an ARC Ref 110 amp, you should understand that generalizations are worthless. How the amp reacts to it's connected components and cabling is as varied as human hearing acuity is variable.