Pre amp recommendations

A6 has issues with USB recognition of some USB DACs.   Way overhyped , support is weak compared to Bluesound and Aurender.   

Wyred4Sound STP SE might do the job. 

I have the Eversolo A8 and use all the features. Streamer replaced my WIIM pro. Preamp is great. XLR out to my amp as well. 

I would seriously look at the new A10 which will equal any HiFi Rose model.

You don’t say what your price range is, but I highly recommend the ARC REF6.  It is a phenomenal preamp and is a perfect complement to my Pass Labs 250.8 amp.  It just sounds great.  Now I will only point out that when I have changed preamps or amps, I have been hyped up on big differences, but the reality is that most of the time there are definitely differences, but they are not night and day.  I mean that one pre will definitely sound “better” than another, but to me, that has been an incremental difference.  Really the one component that I put into my system that really kicked it up to another level and filled in some of what I felt was lacking — namely depth of soundstage — was a Shunyata Everest power conditioner with a Sigma XC power cable.  I was super surprised that it made such a difference!

Audio GD  HE-1 XLR with 10 tubes and it's own regenerative power supply....$4500....Plays with the 10 K crowd. Awesome unit.