what pre amp for ATC SCM 40v2 spkrs + 250.5 Pass Labs pwr amp


Hi Friends!
I'm looking for everything, more detail, larger sound stage, more low end etc. 

I'm currently using a Naim N-272 streamer dac pre, though good I'm looking for better.

I'm pondering on Schiit Yggdrasil gen 2 and Freya +, 
or
AR Ref 3  and  Yggdrasil  (Ref 5 is out of my budget).

Will be using blusound node2i as streamer. 

I'm looking for
1) general experience what works well with the SCM40v2 (as these are keepers) 
2) as well as technical advice on a matching Pre with my 250.5 (specs below)
eg. input impedance (as I've only been reading chatter about this but don't know how to utilize this data). 
I will be using all XLR since the gear above supports. 

Anyone with experience to lend?
128x128hsotnicm
There aren't vintage tube preamps that support the standard, as they are all single-ended. The oldest tube preamps that support the standard were made by us- we made the first balanced line preamps back in 1989. IIRC Rowland was the second to make such, but to my knowledge didn't support the standard. One easy way to tell is whether RCA outputs are provided in addition to the XLR outputs; if they are then the standard likely isn't supported. This is because RCAs do reference ground, where as an XLR connection should not- they are inherently incompatible.


As best I can tell the Pass Labs preamps don't support the standard.


Now you don't *have* to have a preamp that supports the standard; if the preamp doesn't it can still sound just fine, you just don't get all the benefits that are supposed to come with balanced line- lack of ground loops, immunity to interconnect cable artifacts and the ability to run really long cables (although the benefit is there even if the connection is only 1 foot long).
I see thank you for the further insight. 
So then I kindly ask which SS pre-amps are you aware that meet these ideals that you mentioned earlier? 


I've been really pleased with how well my VAC Ren MKV preamp pairs with my Pass XA30.8 amp, and hence picked Ralph's brain a bit about whether the preamp design lends itself towards good compatibility - including excellent and tight bass extension.  From the sounds of it, the VAC's transformer- coupled Class A1 balanced triode design is likely responsible for a large piece of the synergy.  I feel the combo is giving me a flavor of the best of SS/tube integration.
Thanks for your input @three_easy_payments, 
which model @tomic601 ? and what kind of system are you running?