The triode setting would be 35 wpc. I own Ref 160’s.
I run my REF 160’s in triode mode (so 70wpc instead of 140wpc). There seems to be little difference in sound levels… only in the triad mode there is a bit more naturalness to the sound.
I periodically switch back to ultra linear and immediately back to triode. Having come from 350wpc Pass amp… where more power is better… not true in the ARC tube world.
The contemporary ARC Reference amps are incredible. Highly recommended.