I measured the Jadis Orchestra Black using my Audio Precision SYS2722 system (see the January 2008 "As We See It").
The Orchestra Black appears to be very similar to the Orchestra Reference Mk.II that Art Dudley reviewed in December 2015. I had various issues measuring the earlier amplifier, including a broken tube, and the fact that as the Orchestra Reference is a fixed-bias design I needed to reset the bias for each of the four new output tubes.
The output impedance was even higher than that of the Reference Mk.II, at close to 3.5 ohms across the…