How do I smooth out violins?

Good point to validate what the recording in question can sound like first Have you heard it sound better on a reference system somewhere?

Once you establish a reference sound, i would look at power conditioningon the preamp as a first attempt to better the sound. That can usually only help if done well. Then i would consider a good tube preamp next if still needed. I can recommnd the arc sp 16 or line stage only version for digital only. Your issue is one that i find the arc preamp addressed very cost effectively for me.

I find your question interesting in that I listen to classical music exclusively on a modest system. I too found the sound of violins too harsh.
I made two changes; I switched to a tube preamp using some great NOS tubes that rolled off the highs a bit, but still sound very open (RCA Blackplates). Strings were finally sounding very natural, and it was now easier to tell which cds were poor recordings.
I next got rid of the Audioquest Type 4 and switched to some Cardas spkr cables which sound more forgiving. The type 4 are very detailed and you might look for a more laid-back cable. It worked for my situation.

If you decide it's the speakers that are the problem I just might be tempted to take them off your hands. I would love to revisit the 1/2e's in my system.

Personally though I do not think the speakers are the culprit.

After reading your post and the responses, I listened to several CDs to see if I could hear anything similiar.

Beethoven Sym #9 1st movement
Bohm and the vienna Phil

Same piece but Karajan and the berliners SACD.

Julia Fischer Bach concertos with ASMF

The Fischer disc was a little fast, but the strings were easy on the ears. no complaints. Of course she was great.
The Bohm was GREAT. Very smooth. No irritation at all.
The Karajan sounded sort of harsh and strident.
Both of the Beethovens were recorded by DG.
The Bach by DECCA.

A lot of CDs are like this with big orchestras. I own a lot of them. Have not listened to them in years, once a I got a better performance and recording. Just a wall of sound that sort of grates on the ears.

I would advise you, as someone said, get a KNOWN well recorded violin heavy piece and listen. If you find it grating on your ears, then maybe you do have a gear peoblem. But remember, if your system will play at least ONE CD with mass violins to your satisfaction, then it will play ALL properly recorded CD the same way. If you modify your system to make BAD cds sound better, what will it make the GOOD cds sound like. Don't say, ' MO Better' :) Beethoven's 5&7 by Carlos Kleiber and the Vienna is considered one of the best classical recordings. Try it.
The Philadelphia Orch with Ormandy was know for it's violin section. But that was on LP. I can't believe I just said that. :) Good Luck.

Cheers

Try listening to some Sonus Faber speakers if you can. Stringed instruments are their forte. The Cremona M's are extremely nice.