Given the price limit specified and the preference for valves, you might try the Schiitt Freya + preamp. It is selectable between a passive setting, zero gain, a "buffered" solid state stage and a tube stage (octal, 4 tubes) with 12dB gain. It is well-reviewed and reasonably-priced. Schiit has a direct sales distribution but their warranty service is good.
Preamp advice
Hi, I am quite new to this hobby.
I currently have a MC 275 mark 6, running with Klipsch La scalas and Sansui AU9900 as preamp. I know the MC tube preamps are a dream machine to pair with the MC 275 but i need recommendations on any other non MC solid/ tube preamps which can be used with my setup.
Always grateful for your recomendations.
Thank you