Pass amp paired with audio research pre?

Audio  research does have its house sound which can be a bit un-involving at times.

Your situation sounds similar to my own.  I've been there, done that.  I spent several years trying to eliminate that lifelessness.  After replacing my speakers, turntable/arm and power amp the sound was a different lifeless.  I got down to my least suspected components - ARC PH-7 and Ref 3.  Jumping ship to another brand was a revelation.  I know people love ARC.  I did.  Things change.

ARC owners can sometimes resemble owners of Linn ;-) .

Ouch! 😂😉

For those of you here who claimed that ARC house sound is uninvolving I would have to disagree with that broad general statement. You should have a listen to the ARC Reference 10 linestage preamp and other Reference series power amps such as the Ref 750 SE vacuum tube monoblock amps. Perhaps the entry level and lower end ARC products might not sound as involving as their Reference series gears. I have only listened to their Reference series gears such as the Ref 10 linestage pre and couple different Reference series models of power amps such as the Ref 750 SE vacuum tube monoblock amps and the newest latest Reference series monoblock amps that were introduced recently (can’t remember model number). So I can’t say for their lower end or entry level series products.

In regards to some of the comments made here about the so-called house sound of a particular brand, I would have to disagree with that. that’s a generalization based on insufficient evidence and facts. The so called and mentioned house sounds might have been attributed by some other components in the chain eg speakers, front end source components (both digital & analog), cablings, etc, etc.
There are so many contributing factors that some people came up with their own conclusions and called it a "house sound".

@bdp24 

ARC owners can sometimes resemble owners of Linn ;-) .

In regards to your statement above, that is not true at all. Not sure what you meant by that. 
I have owned Linn products in the past and currently own ARC Reference series gears.