What preamp between Burmester and Krell?

I am considering preamp upgrade. It will be obviouslu an used device. Choosing between Krel KBL line stage (former Stereophile Class D in the 90's), Burmester 846 (line stage) and Burmester 785. I am not very familiar with the German preamps, so I want your advice. The rest of the set up is Von Schweikert VR 6 speakers, Esoteric DV 60,s CD player, Audio Note p Zero monos power amplifiers and a phono as analog front.
Please, help!
N. Milkov