I have heard both the CJ and ARC. I find the ARC to have the blackest background, but a bit sterile. The CJ 16LS is very warm and engaging. BTW, I own the Pass X1. Chose it over the CJ and the ARC. It is as Ivanj describes. Warm and very transparent. It does not possess the excess of harmonics generally produced by tubes, that causes all instruments to bloom whether they should or not.
It is easy to find CJ and ARC to audition. Very difficult to find the X1.
It is easy to find CJ and ARC to audition. Very difficult to find the X1.