well my thinking is that, if you're going with virgos, you're probably not a dynmics junky, and don't do heavy percussion, rock, regae, new world, etc,...right? if you're more into vocals, instrumentals, quartet, jazz, light classical, etc, you could do just fine with a good passsive, or cd player with volume control(no pre)! This will yield you the most transparant sound for sure(granted good interconnects used of course). In solid state, you'd have to do expensive solid state to do better with this kind of music. Also, tubes would get pricey for more transparent, less colored sound, but it's possible. if you find a good used CAT preamp, or Audio Research Ref 1 or 2, CJ 16 or something, Copeland pre or similar, you would be very pleased with the sond I think. I'm sure the likes of Cary, VAC, or Jadis probably make a very good tube preamp that's pretty good too. Infact I'm sure there's many. I also think you'd like the transparancy of tube pre's such as older Sonic Frontiers L-2 or 3, or newer Line 2's. The Modulus 3a might work, but you'd have to try...the only way to know for sure. In the end, you'll have to give something a try, and see what you think, for sure. However, I think you should give a good passive a try...at the very least to compare to other pre's in the future...because they won't get more transparent sounding in terms of lack of coloration than those for certain.
Good luck
Good luck