When does A -->B?

It bc totally depends uponh how it is biased.
What you got?

Maybe at 10% power level?

I had a pair you won't care when they change, you won't notice a single thing.. IF you can you got some serious chops.. I could only envy..

They are built on a very low to ZERO feed back.. BUT he (James B) voiced them with actual planars in mind. I met that guy several times once at the old VMPS shop in 2002 or so. Single malt was the flavor of the night.. Good jaz guy.. Keyboards. They called him Pimp Daddy!
He wore a straw fedora with a blood pink shirt.. NO I don't drink.. THEY sure did. I was auditioning a pair of RM40s

VERY serious amps.. They work very well in Tri mode too with good speakers.. Trinaural processor.. SST.. good stuff..

Regards

@oldhvymec -   BUT he (James B) voiced them with actual planars in mind.

 Yes, I've run my Maggies with a class A Forte 1A 50 wpc, Hegel H190 150 wpc and a Michael Yee Audio PA-1 100wpc.

They sound the best with the Ampzillas.

They work very well in Tri mode too with good speakers.. Trinaural processor. 

I wasn't aware of Tri mode.  Have you done this?  Aside from cables, does this require anything more than just adding a third Ampzilla?