Best Vintage tube amp / preamp manufacturer

I have a Citation I and an MC275, both modded/restored by my buddy Mike Samra. Incredible pieces, I recently went speaker shopping and none of the $$$ demo pre’s and power amps did much to make me long for newer gear. I recently retubed the preamp’s line section with Mullards from Jim McShane. 

Audio research.

@koh_i_noor If you like the old ARC stuff (like the SP-3) then if you can find an H/K Citation 1 and have it refurbished you're in for a pleasant surprise. The weak bit about the Citation was its connectors (which were the only game out there at the time) aren't very nice. But otherwise I think its a better preamp.

A Sansui AU 11 if originally offered as a model in the US will be a very nice Amp. 

My main experience is with  CD used as a Source. 

The in built Phonostage in use with a SUT, has also raised a few smiles from those who have heard this.

Ralph I have Harman Kardon old preamp citations and the amp.who does refurbish this units?