Matching pre-amp with Pass Aleph 30


I am currently using a Plinius 8100 as a pre-amp to the superb Aleph 30. I'm looking for more magic in the mid-range and better bass. However, I'm most worried about the bloominess that is often associated with tube amps. My speakers are the ProAc Tablette 50 Signature which most people claim should go with tubes.

Now the concern is that the impedance of Aleph 30 is 47Kohm and most tube pre-amps need at least 50Kohm for a good match.

So, I'm at a loss. Will I be stuck with a solid state pre-amp? Or rather, can anyone advise me on a good matching tube pre-amp?
shsohis
Thansk for the recommendations. I just bought a Sonic Frontiers Anthem Pre 1L and it will arrive this week. Before that happens, any one owns one before and would like to comment on this "budget" tube pre amp?
The Sovtek 6922 tubes are a big worry. I hated thin sounding tubes. Will the Mullard 6922 be a good replacement for the stock Sovtek for the Sonic Frontiers Anthem Pre 1L?

Many thanks!