I believe the X series amps, which are class A/AB, are biased in full class A to 20% and then switch to class AB. For the X5, that means 25W into 8 ohms Class A and thereafter up to 125W into 8 ohms Class AB.
I believe Nelson Pass used this same percentage on the Threshold S series amps as well.
I believe Nelson Pass used this same percentage on the Threshold S series amps as well.