Can a direct CD to amp connection degrade sound?


I've had a Cary 300/200 for over a year and always ran it thru my Rogue 99 pre amp. A week ago I tried going CD to my Rogue Zeus amp direct. Many ads suggested that with a volume-control CDP, a pre was a waste. Sounded right on paper, sounded very wrong in person. The sound without the pre was flat,tinny. There was no air around instruments. What happened? How can a pre improve a CDP's signal when the whole point is to leave the signal unchanged? Has anyone tried it both ways and compared the results?
manorraul
Throughout the years, I've seen more negative than positive comments when people go directly from the CD player to the amp.
I am running an Art Audio PX-25 direct to a Audio Aero Capitole MK2 and it sounds better in my system then it did with a BAT VK50SE!!!!! You have to listen to it in your system and let your ears be the judge--------
I have tried a couple pre-amps with my GNSC modded Wadia 850, and never found anything that gave a significant improvement. Most take something away. Even when I felt like there was an improvement in some parameter, there was more lost in other parameters that made it a net loss. IMO
Neither unit mentions impedance so I assume all you can do is try. The Cary can be set for a lower output voltage and I may try that. Anyway, thanks for the education
Manorraul, contact the manufacturers. They should be able to give you the spec's.