Thank you Dr.House.. so now I know I have the latest version of the amp. The owner's manual on the Axiom web site still shows a trim level and bypass setting, and my paper copy that came with the sub is a " hybrid " version.. picture reflects back of amp..instructions reflect old amp with trim and bypass. I guess the manual is in a transition from old amp to new amp.

Acoustic Zen Adagio, Veritas center, Axiom EP500, QS8s, Anthem AVM20, MC20,Adcom GFA7400