Tube Preamps?

A good one - from sound and reliability - is a used Lamm LL2

Licoricepizza2, Re impedance matching I mentioned earlier, 24.3K and a pre-amp with 3500 output impedance might integrate well especially if the 'tightest' bass is not an objective, nor a bit of bass bloom at times is objectionable to you. That is what you might expect from your system I think. BTW I used to own an identical amp, a nice amp especially tonally speaking.

Keeping your costs down you might consider pre-amps that come up time to time which can do the job you want consistent with your other components. I used (and still have actually) a Magus pre-amp which I used as a back up to my ARC SP10. When these appear they usually sell between $500 and $750.

Re some of the above recommendations, I think the Conrad Johnson PV 5 is excellent and easy to use. I also think the AI 3A is as well but, unfortunately doesn't have great flexibility tube wise to change it tone if you want to, but you also have to deal with two volume controls, one per channel. Too bad they didn't use these volume controls as gain controls with a master volume control (as the Magus does), but for me the ARC SP82 (revision 7 if possible) would be an outstanding choice if you can afford one that is in top condition. The ARC SP 9 looks cool but sounds sterile and I wouldn't own one at any price.

Hope that helps a bit.

I would say $1,000 and below.

I'm going to look around for a decent CJ5. I'm definitely not interested in something that will make my ears bleed. I went that route decades ago. I'm still recovering.