Tube Preamps.....

I second the Denafrips DAC. For preamps, I’ve had a half dozen or so, but a few years ago bought a demo Rogue Metis Magnum for only $1100 (didn’t even listen to the stock tubes initially) and being new to tube preamps paired w solid state amps, over a year and a half stretch of obsession, rolled about $4k worth of 6SN7 and VT99 tubes (w adapters). I ultimately declared a clear winner.. and that was the NOS (or even used) VT-99 Tung Sol’s (also black glass like their 6SN7 brothers). In the VT-99, flat plate or round plate.. both are suprisingly similar, they were dramatically quieter, higher bandwidth, and therefore more revealing than anything else. Raytheon’s and Sylvania grey glass (from Argentina) were also excellent but a step back from TS VT99. Even Tung Sol’s crazy expensive much heralded round plate 6SN7 didn’t come close.. too noisy and twice and expensive. On a lark one day, i put in the original tubes (still low hrs) and they were unlistenable, relatively speaking. I’m not sure how the preamp garnered such rave reviews with them, but perhaps i’d just been spoiled . I believe the Metis loves great NOS VT-99’s w adapters because it separates the main power lead from the interior of the Tube, which is important in a lower tier preamp such as the Metis. Expensive tube preamps are probably less sensitive to rolling, but this one needs the separated lead to operate quietly. Here, It is a very dynamic, transparent preamp which injects the perfect amount of 2nd harmonic distortion into my solid state equipment chain. So you’re looking at maybe $1200-1400 (w NOS tubes and adapters) for a giant killer.

Audible Illusions w/ the Curl phono stage..

I would concur with recomondarions on preamps based with 6SN7 tubes. There is something special about this tube type, and there is (relatively speaking) a great selection of old tubes that you can roll with terrific sonic changes. Something SS will never do.

By all accounts the Don Sachs is a great one. I’ve have a Modright ls100, a Supratek. , and a Wyetech in my system. For my system synergy the Wyetech was the winner. YMMV.

Buying new with return / home trial is prudent. So is buying used at a fare price as you should be able to resell and not loose much. Good luck with your search!

For the best transparency without missing the best tube qualities (that are not always here when we have a tube item in hands): deep soundstage, harmonic developpement without dry signs, I would suggest  the Coincident Statement Linestage. I have one and could compare it directly to AR ref5se and my ex Rogue Hera 2, the Coincident is without doubt better than these two pretenders,  better transparency and fluidity. 

For a really good quality/price ratio, and if you don’t use usb input for your front digital audio gear (as the usb input is not up to date), you can find a second hand Ayon Skylla2 dac that is a dac with two 6h30 tubes per channel as output stage, tube retified, with three different gain ratio and volume control, so it’s a real dac with tube preamp inside. Beautiful association with solid state power amps that would be a bit too much on the solid state side of sound: excellent with Accuphase, too gentle for Passlabs.

I'm surprised no one's mentioned the Linear Tube Audio MZ2, a very fine little 6SN7 based preamp with separate linear power supply.  I got a Freya, and was quite happy with it, until I tried the LTA, and have not gone back (Freya for sale).  And that is before doing any tube rolling, which I look forward to.  BTW, well below your budget.

Don ivey