Preamps for $300 to match with B&K st-140?


Im trying to get a little more warmth and power to my JM Labs Chorus 706's so I picked up a B&K st 140 amp. Now I need a pre to go with it. I want something under $300 that has a tone bypass, and maybe a phono input. Im going used so vintage is ok. Tubes are good too. Thanks for the help!
bundee1
Do you remember what model Rotel? Ill look around for an FT audio model as well. Thanks. Anyone else with this amp, who has a suggestion?
I have used a Counterpoint 7.1 tube pre with the ST140 for a long time. A very musical combo. They can be had for 275.00 to 350.00 pre owned.
I'll put in a vote for the B&K Pro 10MC preamp. Stereophile Class C in it's day. Nice phono stage, external power supply, balanced output, can be used as a passive preamp. I used one for several years and thought it was a pretty impeccable for it's $850 list price.
You should be able to pick up an older conrad johnson tube pre (like a pv 1 or 2) or in ss, a mccormack micro line drive.