Have no time to read all of the mammoth tread but I vote for Promitheus TVC. I have not heard them all but just can`t imagine another preamp for $500 that comes even close to it.
Preamp Deal of the Century
If anyone is looking for a true "World Class" preamp at a very fair price..heed my advice. I just recieved a Supratek Syrah preamp that was hand built by Mick Maloney in Western Australia, and it is absolutely beautiful! This preamp is the best deal you will ever find. I would put it up against any preamp out there for both looks and sound. Price? $2500 for the Syrah (includes Killer Phono stage). Not into phono? Try the Chardonney line stage for $2100. Don't get me wrong, I am not associated with this company. I am just a very happy owner! This preamp is VERY dynamic, yet liquid. It conveys the sound of music better than any other preamp that I have ever heard! You can check out the Supratek website at www. cantech.net.au