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?
lightminer
There are two ways to make an OTL work with 4 ohms really efficiently.

The first is to make it so big that 4 ohms is no worries (our MA-2 and MA-3 are examples of that- the MA-2 makes its maximum power into 5 ohms and the MA-3 makes its maximum power into 3 ohms). The second way is to use a set of ZEROs (http://www.zeroimpedance.com)

If you are planning to bi-amplify the latter method will allow you to use a smaller amplifier, which may well be just fine if it is only handling higher frequencies. The ZEROs can be a very effective solution for using smaller tube amplifiers on lower impedance loads.
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.
Response34, I had a push pull amp from McAlister Audio back in 2005 (believe it was called something 140, 70 watts/channel). Problem with his amp was very poor build quality, although the sound was good. The output transformers had laminations missing that was filled in with small pieces of metal and was caked with this greenish stuff that looked like it was oxidized from years of use. The soldering job was by far the worst I have ever seen, looked like a 10 year old had at it. Speaker binding posts were completely loose when it came to me. Fortunately it cost only around $1600 at the time. I was not the first who had issues with build quality of his amps. I sold it after less than 1 year of use for about $700, but it broke down less than a week after sale. He is now charging close to $9000 for his OTL amp. The outside cosmetics has been upgraded, but I hope he has vastly improved his build quality and reliability for this amount of money. He can take a lesson from the build quality and reliability of Atma-Sphere amps. BTW I have no financial or personal affiliation with Atma-Sphere.
there's a lot of hearsay in this thread, so I won't refrain from adding mine:

A good friend of mine has successfully used Maggies with two ZH270 by David Berning - nowadays you might want to go with the Quadrature Z, that would be heaven!

Said friend later changed to Ambience speakers, but the Bernings are still there..
03-25-11: Rushton
While an Atma-Sphere MA-1 certainly works with the Magnepan 3.6 speakers, particularly in smaller rooms and at lower volumes, these speakers absolutely shine when driven by the Atma-Sphere MA-2. A marvelous combination.
Rushton (Reviews | Threads | Answers | This Thread)

I will give a hearty second to Rushton's suggestion. He and I listened to his MA-2s on my 3.6Rs and it was a marvelous combination in a medium sized room (16.5 x 23)