John E. Johnson, Jr. has posted a review of the Lamm LL2.1 preamplifer ($5,990), along with a full suite of measurements, at Secrets of Home Theater and High Fidelity. His conclusions:
In absolute terms, $6,000 for a preamplifier seems like a lot of money, and it is. But, I paid almost $3 for a loaf of bread the other day. It was really good, and worth the higher price. So is the Lamm LL2.1 Deluxe Stereo Tube Preamplifier. You get what you pay for, and although it may seem like levity, I think you are getting a little more than you pay for with this product.
You can read the full review here.
Paired with the Lamm ML2.1 monoblocks and efficient speakers like the Wilson Sashas would make a really nice system, and it would not cost six figures.