OTL Tube Amps-- are they superior to everything?

Apparently, you have not heard of the David Berning ZH 270. Uses only 4 output tubes, idles at 100 watts, weighs 10 lbs. And will drive any speaker you throw at it(power actually increases, as Ohms decrease). It does not suffer from the traditional "comprimises" as the other OTL's out there, yet retains all of the qualities that make an OTL great. Saxo, I highly recommend you check out the Berning website. It is an incredible product.
Kris

"Gs5556" is pretty much on the money. You have to be careful with what, and how they are mated with speakers. But, when they are matched correctly they exhibit a most voluptuous, detailed, delicate and dynamic soundstage. In short it has that "reach out and touch me" sound that is so real. Not strident or harsh at all. The bass is not as tight as the solid state kings but, the overall sound just washes away what minor weaknesses it has. They are superb sounding to say the least.

I have used the Atmasphere MA-1 with the Music "Z" transformer on both my Maggie 1.6 and 3.6 speakers. The auto-transformer is needed, actually it is a must for these speakers but, once set correctly for the impedance transformation it produced a most enjoyable sound. My favorite so far. I believe bi-amping would be the best way to go on the Maggies. Solid state on the low end and OTL on mid panel and ribbon.

I have also heard the Atmashpere at length on Sound Lab electrostatic speakers. No auto-transformer is needed here as the SLs exhibit a higher impedance. Spectacular sound here as well. Perhaps this type speaker is the best match of all for an OTL. Quality solid state amps sound very clean but just a little steril and maybe a touch less dynamic by comparison.

Check out the "OTL Online" forum. Lots of good information here. No problems with tubes on the Atmasphere. The design is mature and extremely stable. And, it is peaked in performance. You will not need to think about tweakes. The amplifier is designed as they all should be, right.

http://www.otlamp.com/forum/

The truth is that the amps and speakers must perform together as a "unit". I would generalize to say that if your speakers drop below 8 ohms anywhere you will miss out on something sonically with almost any OTL amp. Several years ago I had Martin-Logan CLS'es and a pair of Fourier Panthere (200W) OTL's...these just didn't cut it despite the conventional wisdom of mating OTL's with stators. More recently I auditioned Atma MA-1 MkII's on my Wilson Sophias. Again, the music's foundation was sorely lacking with this pairing. In contrast, I am using Nagra VPA's which have output transformers but are rated at about one-third the output power of the Atma's. These give up nothing to the Atma's in terms of clarity, naturalness and soundspace and in addition they control the bottom end like a Krell. So while it may sound esoteric to say your amps are OTL's, or pure Class A, or single-ended etc. it's their match with your speakers rather than the design parameters that matter. I would go further to generalize that amps that work well with a wider variety of speakers are better designs than ones that have matching limitations.

While i haven't heard a ton of different OTL's, i do know that the Atma's sound very nice. As Gs mentions above, any design is a compromise of sorts and OTL's are no different.

Having said that, i know that Brian, who is the President of the Chicago Audio Society, recently switched from Atma-Sphere's to the new Parasound JC-1's. He's using these to drive his Sound Lab's. From the brief communications that i've had with him about this, he said that the JC-1 delivers all of the air, liquidity and finesse of the Atma's with the bass impact and slam that one expects from a "kick ass" SS amp. I know that both he and Bob Crump were pleasantly surprised with the results of this side by side comparison. Sean
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As stated above, optimal matching of the speaker and amplifier is a must. I don't think this is terribly difficult. There is a product called the ZERO autoformer (www.zeroimpedance.com) that will allow for more speaker choices, and is anything but a compromise in practical terms.

BTW, I am using Atma-Sphere M-60 amps with Köchel K300 horns. In my setup the XLO Signature Shotgun speaker cables I use are vastly superior to the ZEROs.

I believe I am achieving superior results, to each his own though I guess.