Dear Ahendler, I cannot tell whether anyone else has already pointed this out to you. You concede that the Zero is an autoformer (not a transformer) and then you bemoan the idea of using one because you would be sticking a "transformer" in the signal path. So, an autoformer is different from a transformer: (1) The audio signal does not have to be induced into secondary windings from primary windings; no hysteresis; (2) The audio signal does not have to traverse a huge coil of wire; (3) Autotransformers therefore have much wider bandwidth and much lower distortion than even a fine quality output transformer. I am not saying that there is no penalty associated with use of a Zero; you need to listen for yourself to determine that. But otherwise, like Ralph says, you need a herd of output tubes to make an OTL work well into a Maggie, no matter how linear the load may be.
OTL Tube Amp for Maggie 3.6?
I've heard OTL needs an impedance curve that never drops below 4, and flat is better. I think Magnepan 3.6s drop here and there below 4, and certainly aren't flat.
So, would OTL not work?
I think from what I've read it wouldn't matter, but would getting one with lots of power make a difference (i.e., Transcendent The Beast) or is that irrelevant?