Audio Research LS3B vs. Conrad Johnson PV10b

The PV10's are not even close to being in the same league. I've owned CJ stuff for the past ten years. A PV12 would be a better consideration. It is leaps and bounds more sophisticated than the "10". At that point it would be a matter of opinion as to which is better. I think the PV12 will be a little warmer sounding perhaps.

I not so sure the last post is correct. The 10B was the last updated PV10. I believe that line stage was based off of the PV-12, since the PV12 had been discontinued. I'm not positive.
Best to call CJ and ask. I own a PV-11 which some like better than the PV-12 even though the PV-12 was newer. In a old Stereophile review they compared the PV-11 the ARLS3 and a Theshold FET10. They liked the CJ the most. Most musical. The Cj has the warmer sound.

Ihave had both AR and CJ preamps but not exactly these same models... anyway... I have found that the AR sound is more linear (freq. response) but a tad grainy (midrange) in comparison to the CJs, which are more musical but lacking the ultimate extreme resolution at both ends.

Please consider that I have not had the more expensive models of both companies - which is exactly what you are evaluating.

Fernando