Well, the good news is at your budget you have plenty of options that’ll likely give you substantial improvements in terms of what you’re looking for, and obviously the hard part is figuring out which one to choose. For what you’re looking for I’d look at Lampizator, Aries Cerat, or Audio Mirror Wave DAC (maybe a demo is possible for this one?) for tubes, and for solid state there’s Bricasti M21, Meitner, Totaldac, Berkeley, MSB, etc. I’d start by reading reviews and whittling down which ones seem to offer most closely the characteristics you’re looking for, especially reviews that may compare to the DAVE or from reviewers who have previously reviewed DAVE, and go from there. Hope there’s something of value here, and best of luck.

