High End SS Preamplifier Ayre, EMM Labs, ML, or Pass

not so sure about the dag comment. i used the 523 with a dag s250 and never thought there might be an inequity. ended up w a luxman duo and haven’t looked back but i think the ml is built to an extraordinary level. i had my doubts when i purchased it(523) but they quickly evaporated.
from a purely aesthetic standpoint the ml and luxman are equal to the dag in build quality. just put your hands on them. one quick note. i also have an ARC ref amp and the sheet metal case should be embarrassing to ARC not to mention the cost of the guts. However it sounds good. 
Too long winded. my apologies.

Looking for that neutral, transparent, accurate tonal harmonic musical reproduction that isn't analytical, dry, lean, or fatiguing.

You've got some great Class-A amps.  Was thinking maybe a preamp from another manufacturer who also makes Class-A amps, like Vitus?  You know he's not gonna create a pre that makes his nice amps sound anything like analytical, dry, lean, or fatiguing in the least, right?  Here's one available here now if you wanna take a look...

https://www.audiogon.com/listings/lis9cc4h-vitus-audio-sl-102-mkii-solid-state

Vitus is top notch, no doubt and bullet proof


maybe I am old fashioned but I have about 6 K hours on my Ref5se..and as yet no real itch to put her out to pasture, after some tube rolling, etc...
Rather than burn a bunch of coin on a different flavor, I am inclined to put a serious HRS base under it...

so as a consequence, I tend to discount the inputs of the hyper-frequent gear changers......

I'm very very happy with my Luxman, but thinking about it, Ayre and Pass ....
To my ears different beasts.

You should listen for yourself because I can't see myself liking both Ayre AND Pass products at the same time.

Another vote for the Ayre KX-R/twenty.  To my ears there is really something special about that pre.