Upgrading preamp. Best for under $1K

@highend64 

Im a little late to the party ... I would certainly give The Music Room a close inspection.  Several pieces of gear within you search parameters!!

https://tmraudio.com/components/preamplifiers/

BENCHMARK , Try to find a used LA-4 pre amp. New,  about 3 K. I have 2 systems, one manages each, like it that much, solid state. Robert TN

Conrad Johnson PF-R (purchased on eBay for $850) and no, I’m not selling you mine.

see if used Ayre preamps are doable for you....wonderful components

Another + for the LTA . I’d try and stick to the used market if you’re okay with that.