Audio Research and Wilson Sabrina

Sam-

I have a Ref150SE. Loved it with my Harbeth 30.2s  I no longer need it having moved to a 2a3 Whammerdyne Amp for my Puré Audio Project Trio 15s which replaced the 30.2s.  If you want a Ref150SE, let me know and I will relist it on Audiogon.

Just a comment about the difference in sonic quality between the Pass X amps and the Audio Research. I ran a Pass X350 with my Sonus Faber Amati... and while the Amati have a little different character than the Wilson... taking that out of the equation (I am very familiar with Wilson speakers)... the Audio Research sounds nothing like the Pass. While the Pass has fast concussive bass and sounds very solid state... the Audio Research has nuanced natural bass as well as a more natural and musical midrange. When I brought an ARC home I intended to switch back and forth. There was no switching. One minute in, I knew no comparisons would be required, and no solid-state amps would be finding their way back into my system. I appreciate a presentation sounds like the real thing. 

@ghdprentice had the same experience only with a Pass 150.8 when I had Olympica 3's. Tried everything to make it work and went back to ARC and the world was round again 😁  The Pass had a very analytical midrange. No richness whatsoever. Good bass and top end extension but that was it. Sold it and the next owner thought the same thing.  

Several years ago a friend let me borrow an X250. Within 5 minutes I knew it was not a good fit.  The bass was thunderous but oh so sterile everywhere else. ARC to my ears just sounds right.  Not trying to sound like a fanboy but it checks all the boxes.

There is a very significant difference the older Pass Labs X series and the latest X.8  

Various factors can contribute to the sonic signature you experience. Examples are mismatched preamp to amp impedance, room acoustics, source components, cabling, etc.

I used to run ARC LS25 and Ref1 into Pass X250.5 driving B&W N803 speakers and never experienced analytical sound anywhere in the frequency range. 
I also ran XA30.8 with Sabrinas using Pass XP-12 and XP-22 preamps. 
Warm and slow, wooly bass. I then switched to X260.8 monos with XP-22 preamp and the additional power tightened up the lower end on the sabrinas and made the presentation much more coherent. 
I had mu buddy’s ARC Ref6 driving the X260.8 for a few weeks so I got a pretty good idea on its sound. Excellent preamp. Compared to XP-22 it throws bigger images and bigger stage. Everything sounds enormous. It takes a bit to get used to. Ultimately, XP-22 is more accurate and no less natural or nuanced than the Ref6. It’s more precise as well. Boils down to what you like. 
None of my Pass components ever sounded analytical. If anything, Pass homogenized the sound and I got bored of the same presentation.

One of the things that always bugged me - fans in the ARC tube amps  what’s the story there? Are they audible when listening at low levels? Who wants to hear the fans going?

I agree that the newer X amps... like the .8 have better rhythm and pace, but still fall short in midrange bloom and natural articulated bass.