Reasonably priced preamplifier

Aesthetix, Janus Signature - pre-owned $6K-ish should be in the conversation

Have you considered McIntosh.  They make both tube and SS.

I enjoy them

BAT VK-80 from Music Direct. Retails at $10K. They are on sale for $7K new. Sounds great, and a case and remote control that spent a lot of time with a CNC machine. 6H30 Super tubes.  Same tubes used by ARC and others, such as Rogue RP-9. 

I don't know if you prefer new or used.  I bought an Ayre Acoustics KX-5 Twenty for about $5300, new they run about $13K.  It's very clean, I can't believe how much I was missing, especially at the lower volume levels, very rich.  It has some of the pass down features of the flagship KX-R model.  

https://www.ayre.com/

gopaljeen

$7K to $8K will buy a brilliant preamp, and some of these are as good as you will find anywhere. They are definitely "different from the herd", stunningly hand built point to point wired, and use the highest quality components available. They are built by passionate and exacting designers, and are works of art.

Aric Audio Motherlode XL if you need XLR or Motherlode II if not. Don Sachs/Lynn Olson designed Raven preamp (sold through Spatial Audio). Supratek Cabernet 6SN7 or Grange.....all can be purchased for $6,500 or less.

For transparency, I own the Aric Audio Motherlode XL.....and it is extraordinary with both tube and solid state amps.