How do I smooth out violins?

Get better equipment or roll off the highs.

Put some DNM reson speaker cable in place of AQ4, will probaly do it for under 200 bucks.

Some very good suggestions and I agree that you should have a reference CD. That said, when I mentioned earlier that I changed my cables, it was the final step to my system.
I agree with those who say start at the source which is your CDP and next the preamp. I also agree that all systems need power conditioning or filtering (I use a Furman), but I think you can find the cause of the harsh highs before heading down that path.

Charles1dad, I disagree with almost everything in your recent post. Take another look at the system in question.

What if only one recording sounds good with a given system? Shoukd you only listen to one recording or do you want to enjoy your music collection?

If there is a need for a line conditioner I am all for it, but not everybody needs one. Also, if the system is not well assembled a power line conditioner is infact a band-aid. Once again take another look at the system in question. Does this look like a well matched system to you or do you see room for improvement?

Your approach of only listening to "Audiophile Approved" recordings and wasting money on a line conditioner is very bad advice.

Pity the pour soul who asked for advice. So far we have:
It might be the speakers and its probably not the speakers.
Buy a tubed preamp and it is not necessary to have a tubed preamp to tame digititis.
Purchase new speaker cables, ICs, power cords and power treatment.
All your recordings are bad, go vinyl.
Start by replacing the source.

I'm sure at this point he is clear on how to proceed. I guess he is fortunate, in that he gets to keep his amp (so far), and no one has invoked demon possession as the only reasonable explanation.

What would be helpful would be comments relating direct experience with the actual components in question, or diagnostic approaches that would allow him to narrow down the field without running megabuck experiments.

I think a reference recording, recommended by the group as being innocent of the offending attributes has a great deal of value. If Charles1dad has a recording of violins that exhibits good coherence, lack of grain, and lack of excessive brightness in his system, and the OP finds the recording still has issues in his system, then it is system related and not an inherent fault of digital reproduction. If, on the other hand, this recording is found by the OP to be satisfactory, then he is going to have to live with the fact that he has somehow selected a bunch of bad recordings. The idea is to help the poor fellow narrow things down without running a series of megabuck experiments.