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
the impedance has to be a good match between the components.
Clearly YOUR components are NOT a good match for a direct connection.
I have had the very same experience as you - three times. I think direct connection only works well in certain special cases.

Arthur
Yep. Sometimes you can get luck and have a good impedance match. But generally, a good line stage is needed to achieve good sound.
In line with Elizabeth's post, does the Cary offer the ability to vary the maximum voltage output? When my vinyl source was offline, I esperimented with running my Wadia 302 directly into my amp with excellent results, but I had to vary the output voltage so that in the Wadia's sweet sport (volume control between 67 and 99) it was not over or underdriving the amp. Of course if it is purely an impledance issue this may not help.
My Wadia 830 and 861 experiences replicate yours when using a Supratek Chenin. The Chenin was an improvement over going direct.