How do I smooth out violins?

I have a decent system (bit of a mixed bag) but know that I can achieve a smoother, more integrated, and more relaxed massed violin sound. I listen to a ton of orchestral music and notice that massed violins in their upper registers (1500-3500 Hz) often jump out from the mix and sound a bit harsh, unlike what one hears live. Right now, I have the following:

Spendor SP1/2E
McCormick DNA-125 (original)
NAD 1600 (pre/tuner)
Marantz CD3000
Audioquest Sidewinder ICs
Audioquest Type 4

Would a tube pre help (maybe a AA M3A)? I'm thinking that the NAD may be the culprit. Any advice from those of you who have quested for "real" violin sound is very much appreciated.
... Massed violins in their upper registers (1500-3500 Hz) OFTEN [emphasis added] jump out from the mix and sound a bit harsh, unlike what one hears live.
As I read it the information provided does not exclude the possibility that it may be a recording issue, as Rok2id suggested.

Have you found this to occur with orchestral recordings that you know to have been recorded with "purist" microphone techniques (e.g., 2 or 3 well placed mics), and that you can say with confidence have been well engineered in other respects? Or have all of the recordings on which you have perceived this problem been heavily multi-mic'd, with the forest of microphones that are typically used for orchestral recordings released by many of the major labels?

-- Al
I think the tube preamp is a good idea along with the cables and power conditioning measures that Elizabeth mentioned.
Mass string is very difficult to reproduce well with digital source. I suggest you start with the CD player. But if you want silky strings, I am afraid you might have to change over to vinyl. IMHO of course.
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.