Audio Research and Wilson Sabrina

@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. 

@ghdprentice Pass bass is what it is. I’ve been living with the Boulder 866 integrated for a year and a half now. It’s got a very firm grip on Sabrina’s bottom end (couldn’t resist the pun). And is extraordinarily musical. Dead quiet non existent noise floor and natural sound that’s never in your face. As always, associated equipment, cables and room acoustics matter. I can make my system sound absolutely horrible by just swapping cables. 

Power is critical with these speakers. Can’t compare Sabrinas to older Sophia that you could drive with a 25w tube amp. Same goes to Watt/Puppy that people used to drive with low power tube amps. 

I also dislike noisy components and distortion. Tube rush and whooshing fans would just piss me off. No midrange bloom could ever compensate for this. I’m hoping ARC has this under control.