There are several good recommendations here. I will give one more Rouge Audio Hera 2 - Hands down the best preamplifier I have heard for the money. Bests other brands, some listed in this post, that cost 3-4 times more. Frequency response is 1hz - 300khz. The sound stage is truly holographic. Rogue Audio discontinued the line due to production costs associated with the level of detail involved with the design, but still services them should anything happen. I am not a rep, nor affiliated with the company. I am an Audiophile that appreciates great craftsmanship especially at reasonable prices.
Good Luck
There is one currently listed on Agon.
https://www.audiogon.com/listings/lis8ii1a-rogue-audio-hera-two-piece-preamplifier-tube