OTL Tube Amps-- are they superior to everything?


A recent conversation I had with an Audiogon member got me interested in OTLs. His opinion is that nothing compares to them for clarity, naturalness and superiority in just about every area. The Atmaspheres are the amps he has, and they are purportedly very stable, unlike most other OTL designs, which many can tell you were a living nightmare.

This is ironic, because some mfrs., like McIntosh, actually put output transformers on their better solid state pieces, claiming they provide superior sonics.

What is the truth here?
saxo
I do agree Allan and don't pretend to understand how this high frequency converter "carries" the signal and increases the turns ratio to 64-1 and matches impedance to the speakers, it is indeed mind boggling! My point is that a converter/transformer, regardless of how radical and different the approach, is used to achieve what this amp does. Explaining HOW it works would be informative to those wanting to understand this innovative design although I don't think it would be readily understood.

Saxo, if a man designs, builds and puts his name on a product and those products have stood the test of time and along the way have added really innovative approaches to solving some of the real world problems in getting the signal to is purest form, I would be less concerned about the complexity and maybe investigate further whether it is something that might work for you. Due to its features (auto-biasing, 3 feedback settings, 2 inputs for line source components), light weight (10 lbs), low heat output (100 watts idle, 300 watts full power) and most importantly sound reproduction I feel quite certain that I will keep it forever. It is just too cool in more ways than one!
Saxo, I apologize. However, I do own a pair of Atma Sphere M60 monoblocks.

Wellfed, yes it was the Paul Speltz Zero Autoformers I tried in my system. For about 1.5 months, on loan from a good friend, whose testimonial is on the website. Beginning with the 2X setting, and also with some higher multiplication configurations.

I do not deny that in your situation, the Zeroes made an improvement. I think that for the majority of loudspeakers, they will not only make that kind of difference, they are required. However, as I noted, there is a significant loss in the OTL magic. My opinion is that if someone were to go down the OTL path, a better option is to choose a high impedence loudspeaker from the get go. That way, none of the life of the OTL amplification is compromised whatsoever.
Yes, Allan, I studied this quite a bit before getting into Berning's amps. I also know about the RF carrier, and the "bus stop" get-on, and get-off routine. But I felt it was of no use to get into that here, because nobody has understood it previously, and I doubt anybody is going to get it now.

By the way, you should hear this battery powered, choke loaded 45 SE ZOTL. It's the cat's ass. I really would like to get an ear on those direct drive 270 amps you have too. I forgot what speakers you are matching them to. What are they?
*** His opinion is that nothing compares to them for clarity, naturalness and superiority in just about every area.

They do have some very specific and very limited qualities that are attractive but mostly the “attractive qualities" get overwhelmed by a large amount of the very critical fundamental imperfections… There is a LOT of more to it but it will be obviously out of scope of the typical Audiogon member’s aptitude. If you looking for serious information but not for the casual audiophile BS then look somewhere alse.

*** The Atmaspheres are the amps he has, and they are purportedly very stable, unlike most other OTL designs, which many can tell you were a living nightmare.

Atmaspheres actually are very poor electroniks and I sincerely feel that to make any conclusions about topology base on the evaluation of a specifically-badly-implemented brand is a wrong thing to do.

*** What is the truth here?

Look for the answers somewhere else.
Twl, I would love to hear those amps of yours, I'll even make a effort to come and hear it, where ever you are :)

My amps are 6JN6 based but not a 270, they are direct drives, directly driving Sound labs, I have over twice the rail voltage of a regular 270 but a lot of the design is similar, this alone is a testament to the reliability and rock steady stability of the design, it's capable of producing 6000v peak to peak, yeah it only weighs 8lbs each, so not only am I OTL amp but I am transformerless on the electrostatic panels as well.
There is an open invitation to anyone to come and hear this, as talk is cheap