OTL Tube Amp for Maggie 3.6?

If anyone knows if it would be better if an OTL tube amp were designed for 3 ohms vs 4 for a Maggie 3.6/3.7 let us know.

Other than that, they seem very suited for what planar speakers do, especially in terms of the fact that planar speakers are so transparent, and then the OTL aspect maintains that through the system.

Another question - because where money is an issue in my systems, I wonder what people would think about matching a relatively cheap ClassD amp, like the Rotel 500 watt ICE in an active bi-amp setting.

I've heard that with active bi-amping amp-matching is important. Remember that the 3.6/3.7s cross over at 200 - 250 Hz, so we are talking low frequencies where quality matters less because of the physics.

Given the high cost of OTL, this would be an interesting option:

24/96 source
Good DAC and Pre
Bryston X-over
Rotel RB-1572 (although I'd love to use the ICE1000 vs 500, they stopped making theirs, I'll poke around for another 1000 module)
Atmasphere MA1 or VZN-160 or The Beast
Maggie 3.6

The OTL amp still consists of most of the cost of all of this, unless one gets The Beast and builds it themselves.

Note that going active bi-amp makes the high-frequency amp at least double in effective power by isolating the range of frequencies it has to deal with at once.

I have to look into The Beast more. The other OTL amps are out of my range at the power required to drive Maggies, for more efficient speakers I'd be there in seconds.

Has anyone heard it recently? Does it really sound as good (or nearly as good, I'm sure it isn't as good) as any of the other OTLs, or is it much more limited in quality? Is it compromised enough that its doesn't that the OTL sound anymore?

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..