Hello Tim
Earlier, I recommended that you should remove all effects from your strings, because the sound sounded quite far from "natural". Example 3 now may sound different (I did not compare again with 1) but still pretty far from "natural".
I repeat myself again:
With the VSL samples you have a great sounding library. People of VSL took great pains to record the samples, edit and publish them. So you get a great sound without doing anything.
What is/was your mixing goal?
I do not know what you wanted to achieve with all the effect you used for your mix. A more pleasant sound?
Whatever you use to judge the sound is obviously anything but neutral. You probably adjusted the sound so that it sounded great with your "reference". To me it sounds quite discolored frankly. If you have the chance, play your mix in your car, or on your hi-fi system...
A possible help
I allowed myself to play BWV 727 with a Midifile - without big sample optimization. It was all about the sound. I chose Chamber-, Appassionata- and Orchestral strings to get an average string sound. Except for a bit of compression and reverb, I did not use any other effect - so no EQ as well! Then I switched between my sound and your sound. The example starts with VSL-pur...
http://www.musik-produktion-createc.ch/BWV727-Ref.wav (23MB)
Do you hear the difference? That's what I mean by "compare to a reference". Reference here is the "original VSL recording sound". If you compare your sound with an analyzer, it looks like this:
http://www.musik-produktion-createc.ch/Teclark7.jpg
Green means original - VSL strings / White is your BWV 727.
Incidentally, you also see that you probably used a stereo widener tool. Especially in the lowest frequencies and from 2kHz above "stereo has become a bit too much" or you used a reverb that makes a bit too much stereo here.
Summarized:
With samples you usually get good results, when you take care of correct volume ratios between the instruments and when you manage the left and right things. Finally a bit of a concert hall at the output and that's it. Such a mini mix often sounds better than a lot of what you can hear in the net, which was "treated with effects" for weeks...
I can only recommend again: Try to use less effects (until you know them better), check your listening situation, use reference sounds and try to hear your own mixes more often on other systems (car, hi-fi, etc.).
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Sorry I was very direct. That might hurt a little. But keep in mind: I would not have taken all the effort if I did not really want to help you. I hope you can see that positively.
I wish you success
With kind regards
Beat