Best Tubed Preamp For A Warm, Rich Sound, Yet Still Detailed and Agile


As the title says, I am looking for an exceptional preamp (obviously tubed) with warmth and liquidity, some of that golden glow, in the midrange and highs. I do not want slowness, or lack of detail, however. My budget is up to $6,000.00, for a used model. 

Based on my research, many of those that might make the list are very rare to find, and other recommendations would be greatly appreciated. 


nightfall
From time to time, you will see a Doshi Alaap come up for sale.  Line state only would be well within your budget but they are more rare.  Full function would be near the top of our range.  Also highly recommend VAC Ren. 
VAC Renaissance mk III would probably fill the bill nicely, very hard to find on the used market though.
If you have not had a Direct Heated Triode preamplifier,, it is thr purest sound you 
Will find . After having  every type. This is the most direct type without question ,
Single ended. I am using a custom Lundahl based 4P1L Vacuum tube 
Preamp.  For 1/2 your  $6'k budget  you can best preamps are 3-4 that in resolution and refinement, Radu Tarta is one of the best engineers 
I have ever met .p.s just look up this tube it is probably the most linear Vacuum tube for  music ,just research  the 4P1L  Vacuum Tube.