Moon North Collection Versus Pass Labs X350 - Which would have that liquid sound?

@dman777 Sure. Meitner MA3i DAC used as roon end point, tidal connect, jplay renderer into Boulder 866 using Kimber KS1116 XLRs, VPI Prime X with Hana Umami Blue into Lab12 Melto 2 or Whest Two.2 (listed for sale), with Kimber Carbon phono cables and Kimber Carbon XLRs into Boulder, with Wilson Sabrina speakers. 
Kimber PK14 base power cord on phono, Kimber PK14 Ascent on DAC, Kimber PK10 Ascent on Boulder. Audience FrontRow speaker cables. 

Dynaudio won’t save you. What power cable are you using with the luxman? I remember I tried AQ Hurricane on my amps and it was so fat sounding with pass labs that I couldn’t tolerate it. It could be just the ticket for your luxman. TMR usually has a few used ones on sale. It’s not a neutral sounding power cord but in your situation might wanna give it a shot. Best yet, add a sub and balance out the sound. You will probably be happier that way. 

Just sitting on the sidelines here. I understand the liquid sound thing. A friend of mine had a 250W Pass and he also had the high end Moon amp/preamp. The Pass was liquid, the Moon was very neutral to the point I did not like it. Don’t ignore what people are saying about the heat coming off those Pass amps, my friend sold his partially due to that issue.

All that said, back to my view from the sidelines, it sounds like you are trying to tame your speakers. I think you should consider a change in that department.

@dman777 I owned Focal Sopra No2 for a while and used a Luxman M900U amp at that time. I have a decent number of years of experience with the M-900u and have used it many different speakers and source gear and know it well. It’s a wonderful amp, still holds its own today. In my opinion it’s not a dead neutral / uber resolving type of amp, but seems to be voiced for a certain kind of beautiful sound. Don’t get me wrong it is plenty detailed and refined but overall it has a kind of tone or slight sheen to it that is really beguiling; I would never call the amp sharp or hard more along the liquid side. That being said I did not enjoy the pairing with Focal No2. Except for a few recordings which sounded incredible, I found the Be tweeter too forward and with an artificial metallic presence that always called attention to itself. I could not get them out of my system fast enough. 
A few years went by and apparently I didn’t learn my lesson with Focal Sopra and bought a pair of No1’s to use with my Luxman L-509x and L-590mkii, and also an Octave integrated- it was pretty much the same ending. There is something about this sopra series that does not agree with me. I find them to be unnatural and hard to relax with. Now, after having owned a few moon amps, most recently the 761 I can easily understand why you are looking for more liquidity. My recommendation is don’t change your amp. The 861 is killer. Change your speakers. 

+1 @audiopacer

@dman777 audition ATC SCM40 passive. I heard these speakers and I can tell you for the money they’re hard, if not impossible, to beat when it comes to reproduction of every genre of music. They will rock as well as do large scale symphonies or acoustic jazz. And won’t hurt you with those 90s rock and punk albums. Better fit in my opinion than the sopras in your case. Good deal without compromising sound quality. 

Interesting thread. I decided to combine the best of both worlds. I have the simaudio Moon 791 preamp and the Passlabs XA 25. The interconnect is a Cardas Clear Rev. 1. I do not claim that it is better than some of the systems described but the synergy is excellent to my ears and given my modest room configuration of 20x11.