Never ABd my Ampzilla 2000 with the JC1. Did listen extensively to the JC1 at CES on the big $18,000 SoundLabs. The JC ran very hot, the A2K always cool. JC much bigger than the A2K. If money relevant, consider the $3000ea Ampzilla stereo amp if it is available now. The A2K is far & away the best amp I've ever heard, making a died in the wool tube nut (me) forsake tubes. Even after over one year, I have still not identified any additive sonic signature to the A2K amps, they get out of the way more than any I know of.