test #1.Could you connect the 9000ES directly to the Rotel power amp and play a not-too loud CD (even beter does the 9000es have a variable output ?).
test #2Alternatively borrow a friend's CD player with a variable output , connect directly to the rotel, and see if it sounds better than your preamp at higher levels.
test#3 borrow an active preamp and experiment.
If any of the above experiments produce the same over-aggressive sound then it might be that the amp is underpowered. Marakanetz was correct to point out that not all watts are the same (well, they are, but the way manufacturers measure them varies). Rotel is a bit of a middle-of-the-road manufacturer ... not at all bad, good value for money, but not all that great either.
If either or both of the above produce a loud, but not so aggressive sound then it would indicate that the preamp is the probably cause of the problems. I don't know why this might be, but it could be an impedance mismatch (since it's a passive pre). In this case switching to an active preamp might solve your problems.
I very much doubt the Sony CD player is the root of the problems.
Good luck.
test #2Alternatively borrow a friend's CD player with a variable output , connect directly to the rotel, and see if it sounds better than your preamp at higher levels.
test#3 borrow an active preamp and experiment.
If any of the above experiments produce the same over-aggressive sound then it might be that the amp is underpowered. Marakanetz was correct to point out that not all watts are the same (well, they are, but the way manufacturers measure them varies). Rotel is a bit of a middle-of-the-road manufacturer ... not at all bad, good value for money, but not all that great either.
If either or both of the above produce a loud, but not so aggressive sound then it would indicate that the preamp is the probably cause of the problems. I don't know why this might be, but it could be an impedance mismatch (since it's a passive pre). In this case switching to an active preamp might solve your problems.
I very much doubt the Sony CD player is the root of the problems.
Good luck.