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. 

There are several in this chain who have pointed you in the direction of Cary's SLP-05 ..... well, I'm hear to tell you they are right.

I'm curious as to if all the folks recommending the Cary SLP-05 have read this comment from the OP:

The amplifier that I will be using the preamp with is superb, but not well known, which is why I failed to mention it earlier. It is the Wells Audio Innamorata, which is single ended with an amplifier input impedance of 50k ohms.

I'm not sure that the SLP-05 is any better than the SLP-98 if you can not run it in balanced mode.
Not to mention the point that Al (almarg) pointed out regarding the SLP-05's output impedance:

While the description of the Innamorata at the Wells Audio website as well as in various reviews indicate its input impedance as 50K, its manual indicates 30K. I don’t know which number is correct, of course, but 30K would be somewhat marginal (or worse) for use with several of the preamps that have been suggested. For example, Stereophile measured the 20 Hz output impedance of the Lamm LL2 at 3.3K, and the 20 Hz output impedance of the Cary SLP-05 at 3.4K, both of which would be just barely acceptable in conjunction with a 30K load, IMO.

This post is a great vehicle for people to pump their favorite preamps, which is great.  However, to actually reach your objectives, you might need a wider view.  Two points I'd make:

(1) In my humble experience, you can only get so much of the tube feel out of the preamp part of the equation.  It's there, but you get the real tubey bang for your buck out of the power amp part of the equation.  So you might consider that budget applied to a tube power amp instead.  This is where the real liquid turbiness comes in, I have found.  Or consider a full-tube integrated.  OR a tube input stage hybrid power amp with a SS output stage.  All of those may give you the full tube experience more than a preamp alone.

(2) I don't mean to say that you don't get good tubiness out of a preamp.  But if you go this way, save a substantial portion of the budget for the tubes.  The hardware is obviously important too, but if you really want to enjoy the whole experience, you'll need some nice new old stock options to play with -- Mullard, Telefunken, the usual suspects, etc.  There are some nice options at Upscale Audio, and Kevin Deal may be able to guide you to both hardware and tubes, but your mileage may vary with Kevin.

Good luck!

I was looking for exactly what the OP is looking for and I found it in the TRL The Dude, which I would rank first, and the CJ Premier 16 LS. Also the MP 1, but not with your amp. 
I currently use both the top rated 2 above and they will be my last preamps ( in different systems) 
I'd look at the Baekert Labs preamps in all price ranges they are giant killers. Bob Baekert has a patent on a new power supply, worked at CJ for years, and the many reviews of the Rhumba and Rhythm have been very positive. Plus, I understand they may be warranting their tubes for 10 years! They are Audiogon. Let Andy know you corresponded with William. Some people like them, some people don't.
As for the other brands mentioned above, many of those are in my repair shop all the time.Some are not. Why do you think people are selling them?
 I'll pass on Deal.