Amp for focal 1038be?

Rotel should not be dismissed.
Rotel amplifiers and Focal speakers  go along well.

Parasound and you probably should consider a number of class D amps out there.

If you are looking for 3D / Holographic detail, assuming a good implementation, you will find 845 based tubes deliver the best on what you are looking for.  I am soundstage obsessed personally and it is my favorite tube.  

Even in Push Pull, an 845 will tend to deliver the widest and deepest soundstage compared to other tube types.  

Secondarily, why so much power?  With a 93dB SPL, assuming you are sitting 10’ from the speakers, you need 37w to hit 105dB in output.  That is the THX guideline for headroom for home theater.  For music you need 12w to deliver 100dB in output.  More power never hurts but you definitely don’t need two MC275s.

I do not offer an 845 based amp in your price range from Art Audio (my 18w unit is like $8500) but you might find a used Cary or even a new Line Magnetic in your price range.  Buying an 845 from a company that has a good reputation for producing them is critical as the amount of current required to drive the tubes is massive.  

Of the ones ones you mention above, I would say the MC275 will probably give you the best soundstage.  I have heard it with multiple Focal products (Electra, Kanta and Sopra) and it was lovely.  It was with a Mac tube preamp and phono stage though.  I am not sure how much was the preamp and how much was the amp.  I still found them a little forward but if you have a well damped room that might be moot.  Better would be a pair of MC75 mono-blocks.  

I’ve had 1038 BE2’s for approx. three years.  I began by powering them with Odyssey Audio 160w per channel Cyclops, moved on to Pass Labs x250.5 paired with Pass XP-10.  Within three months both were traded in for x250.8 amp and XP-20 Pre.  Marked improvement with each upgrade (especially from the Odyssey to the Pass brand) I highly recommended the x250.  If you can’t afford the .8 go with the 5.  Cables matter!  The 1038BE2’s benefit from high quality cables.  In my case Acoustic Zen Hologram 2’s.  With my current set up they image wonderfully.  You will hear instruments playing far outside of the speakers which at times, you may be startled by it.   Oh and pick up some Gaia isolation feet to further enhance the imaging and sound quality.  They are wonderful speakers, classics in fact, currently selling for a song.  Enjoy!