Noam Bronstein has posted a review of the Elekit TU-8500 tube preamplifier kit ($550) at Wall of Sound. His conclusions:
“I’ve owned many preamps over the years, both tube and solid-state (as well as passive). For me, the Elekit strikes an impressive balance of performance, usability, and low cost. The key point being, it’s a kit: if you think this sounds like a “$500 preamp”, think again! A unit of this calibre, if assembled and warrantied by a respected audio house, would retail for 2-3 times that much.”
You can read the full review here.