Preamp for Mccormack .5 monos

I have been reading alot of good reviews about the TAD 150,(which I know that it is not being produced anymore)Audio Mirror T61 or the Eastern electric minimax.Which one of these would best fit my amps?They have got a 10k input impedance.I am also running Vandersteen 3a sigs.
Anything that has fine steps in volume control should work fine. A friend of mine uses Sonic Frontiers Line-1 preamp with his DNA-125 that also has 10k input. I brought over my ARC LS-25 and it did a very fine job as well. Look for something with 80+ steps in volume control. I had ARC LS-15 with my DNA-125 and then DAN-225 and while it did sound excellent, I struggled to fine tune the volume because of limited number of steps. It would either be too low or too loud all of a sudden. Problematic for late night listening, which is why I upgraded to LS-25. but sonically, LS-15 was great.
Anyway, I assume you're looking at an affordable tube pre. If so, Sonic Frontiers Line-1 may fit your bill perfectly. It is a really nice sounding pre. If you are going to look into one, get the SE version.

Good luck.
check out the new Jeff Rowland Capri pre-amp. It has 99 db steps in .5 increments.
VAC products pair very well with McCormack.