You can't go too wrong trying the Soundstream DAC. If you don't like it you should be able to resell it an get your money back no problem. I try out equipment this way a lot. In my experience Rotel equipment also tends to be on the bright side with the one exception being the Rotel RCD-990 CD player mentioned (and probably the RCD-991). I use to own a Rotel RCD-940 years ago and found the Van Den Hul "The First" Interconnects worked wonders. It is a very detailed but still laid back cable. Read the reviews at Audioreview.com that confirm this. They are pricey new, but I've seen used pairs for $90 to $125 depending on length.
Will a DAC mellow Denon DCM 360
Will a low-end DAC help mellow the high freq edges of my Denon DCM 360 carousel. I've seen ads for the Soundstream DAC-1 ($100) and Musical Fidelity X-DAC ($70) around and wonder if they would be any help? Or is the money better spent on a different cd player? My system is Rotel RB-980BX amp(120 W), ROtel RC-972 pre-amp, B&W 601 series 2 speakers, DIY TNT-X 1.5 connects, and DIY Chris Venhaus Cat 5 (27 pair)teflon speaker cables. My current system sounds excellent for the $1,100 I paid (new speakers & stands, used electronics), except for the piercing highs on some cd's. The DIY cables & interconnects provided a great sonic improvement (excellent detail and soundstaging, much tighter bass) as compared to the cheap Radio Shack "Goldseries" connects and monster cable I was using. The only problem is that the better the interconnect/cables the more "edgey" highs that the CDP delivers.