What's the best pre-amp to use with the Acurus

I really can't recall, but I seem to remember the Acurus as having a rather a rather low input impedance. Finding a compatible tube pre might be a challenge.
I remember the Acurus amp as having bass capabilities way beyond it's price point, unfortunately I also remember the upper end being dry and chalky.
If you can find a tube pre that has an appropriate output impedance, I think that might be the way to go.

I had an A80 paired briefly w/an Aud Illusion M3, and it produced a transparent soundstage that blew my mind...truly three dimensional and DEEEEP. However, it was a bit too bright in the upper end, which was the Acurus. You might try a CJ or Cary. These are a little warmer and would pair well w/the more forward upper end.

After having used an RL10 with the one I used to own I would recommend a tube preamp.

cont'd (couldn't edit post)

...a tube preamp with a low output impedance. Maybe a Quicksilver or something.