Preamp or DAC

Nice system! I would vote preamp for sure. The May is well reviewed and well liked. I have a Coda #8 and tried the 07x, it was not my favorite out of the four solid state preamps I tried. Each one was unique and made a big difference, I think a DAC change would be more subtle. Given your system and budget, this will be a seismic upgrade. I will leave tube preamp recommendations for those with experience with the gear. 

Replace them both with a good tube DAC. I use a lampizator tube dac and no pre. However, the volume control on the Lampi isn’t great so I use a Transformer Volume Control.

Jerry

Thank you for your input. Interesting thoughts. I had always believed the preamp mad a difference in whatever system I had at the time. I have tried eliminating the preamp and it has not sounded quite right to me. However, I have not tried it with a Dac the caliber of pretty much any of the Lampis. 

@zlone by the way could you tell me your favorite of the preamps you tried please. Thanks. Looks like Pass 12 maybe?

If you decide on upgrading the preamp, look into Backert Labs. The Rhythm 1.4 is in your price range and it is fantastic. 
if you decide to upgrade DAC, I have a Lampizator. I just demoed 4 other DACs and have decided to stay with and upgrade to another Lampi. But if I did t want a vol control, I would be choosing the Aqua La Scala DAC that was so engaging. 

But also, the idea of splitting your budget into both pre and DAC could still lead to an upgrade in sonic performance.