preamp for mark levinson 23.5

what is the best preamp for levinson 23.5 amp.
now i have mark levinson 26 preamp.
Best preamp is the Mark Levinson 26, or 26S. Or the Mark Levinson ML7 or the ML7A.
The ML25s is a superb preamp especially if you can get the line stage and then get the 25s phons stage. I would not go for the ML7 but see if you can find a ML6a or b as they are a significant improvement on the 7. They are obviously more expensive but.....

A@com, If you own the 26 Levinson preamp, your all set, thats one of the best preamps ever. It matches perfectly with the 23.5 Amp. How do you like the 23.5 Amp
Anyone else using vintage ML gear currently?