If you don't need total isolation, ZMF v1 is very good--especially with the darker string instruments. But it will handle violins well too on account of its effortless extended treble. One can hear the influence of HE500 in vocals, but I think I'm hearing some HD650 too.
Another choice, if you're willing to accept on ear, is Mikros 90. It's a little bright / colored (in the direction of Grados but not all the way) so it doesn't work so well for orchestral music but it works pretty well for strings.