Here is my two cents. The Primaluna 12AX7 based for $2200 new is a very musical preamp. The Quick silver is a nice sounding preamp not as tube sounding versus the Prima. The
deHavilland is a good sounding tubish sounding preamp but I have only heard it after I modified the unit with my upgrades for a buddy of mine. The upgrades included V-Caps, volume control, some tube sockets, transformer (much bigger thatn the junkie stock one, AC filter choke, resistors, and a few other changes. Those upgrades gave the preamp a much bigger dimension, better detail, made it quieter, and with more space between instruments. The stock unit to me was nothing special. Other options would be a Counterpoint SA-3000. It has phone which is OK for an old preamp. These I can perform upgrades that bring them to a new level. I also like the SA-3000 for the separate power transformer which helps eliminate noise. Besides parts upgrades I can upgrade the circuit to today's level and is basically a new preamp. All of the above are good choices.
Happy Listening.
Happy Listening.