modified jolida 100, mh cd-25, or audio aero prima

How about the unmodified Jolida with some NOS tubes 5751...it blew away my $4000 YBA. There is no glaring need to modify this unit. IT will save you some money to buy stock and nice set of tubes. Haven't heard the PRIMA...Good Luck

I totally agree with Aniwolfe, the Jolida doesnt
need modification, may be good tubes only.I heard
this player, the performer are in the room.

I haven't tried the Jolida or Mh players, but I do own the Prima and the Capitole mk 2, as well as having owned quite a few other highly regarded players over the years. I would take the Audio Aero Prima over the Wadia 860x, ML 39, Meridian 508.24,or Resolution Audio CD 50. I have owned or had fist hand experience with all these players and I think the Prima beats them all, in fact I feel that it's performance is very close to the highly regarded as one of the best players period, Capitole Mk 2. The price difference between the Capitole 2 and the Prima is hardly justified. I think you'll be hard pressed to find a better player under 2k

As far as the Jolida is concerned.

Which tubes would improve the highs the most without much sacrifice elsewhere?

Get the Jolida and you will have money to spend elsewhere. It is an outstanding player for the money (modified or not).