jkohn,
I'm hip to your jive brother! I too am very happy with my separates and would not want to give up anything in sound quality because of an inferior DAC. But the two reviews (current issue of Absoulute Sound and Enjoy the Music.com) I've seen on the Ultracurve Pro are mighty convincing.
In the AS review, the reviewer recommends it for eqing the sub only and for "experimental" purposes. The reviewer at ETM.Com rcommends it for the whole system. I know there are frequency "suckouts" and "humps" in my/all system at the listen position (my trusty Radio Shack SPL meter confirms this) and its buggin' the crap out of me knowing that, as good as my system sounds, it could sound better without the hills and valleys . Having to give up sound quality for flatter response really sucks but I wonder just how much sound quality would really suffer. Perhaps I'll get one for the sub only and then, for the heck of it, eq the whole system. I'll never know unless I try it, besides its not gosh awful expensive . I'll give you a report if I decide to go ahead.
