Not sure if it would be a step up in all areas, but there are brand new Audio Research LS17SEs for sale here now near your price range at less than half their retail price. Also a new PrimaLuna Dialogue Premium in your price range as well. Not familiar with your preamp or what specifically you're looking to improve upon, but I'd think these units might at least be worth a look. Best of luck.
Climbing the Preamp ladder
Bat vk-3, Manley Shrimp, and am currently using a Bat vk3-ix. you see I like tubes. what is a good step up? not just different. I use a Rogue stereo 90 tube amp with Aerial 8 speakers. I have a musical fidelity m1 transport and a wadia 121 DAC. I would like to stay under $2500.
thanks for everything in advance.