Looking for a tube Preamp new or used for under $2000...

+1 for rogue rp1.  Same as u went from parasound p6 to rogue.   Helped in imaging  and added organic sound to voices.  So good I then bought a rogue st100 amp.  Sounds awesome.  

I have a PrimaLuna Prologue 3 preamp in great shape that I am planning on listing for under $1,000. Let me know if you’re interested.

I also have the A21 but with the P5 pre.  I have also wondered what a tube preamp would do for that vaunted “tube sound”.  I’m looking at these options as well.  👍🏻

If you have the patience to wait, I'd suggest keeping an eye out for a Backert Labs Rhumba tube preamp. They sell for ~$2k used, but only show up every couple/few months. It's a great sounding preamp and the manufacturer provides outstanding support. 

I would not go for a tube preamp with a parasound amp i have owned a parsound amp for twenty years and even my audio research pre amp will not work with it the impedance mismatch is too great to overcome. Find yourself a better solid state pre amp even a good vintage one will vastly out perform a new parasound preamplifier. I have owned two parasound preamps and switched to other companies offerings because of better sound reasons.