OTL Tube Amps-- are they superior to everything?

I would highly recomment that you at least try an Atmasphere so that you can experience the true sound of a pure analog OTL piece of equipment. Does not matter whether you find it better, worse or indifferent. You just need to hear it when it matched up well to a speaker(with or without the auto-transformer).

There is just a gain stage then an output stage with zero feedback. Simple and truthful. No transformers or switchmode trick circuits. I personally think the magical OTL sound could be due to several different reasons. One, maybe distortion. Wegel and Lane(couple audio guru's) in 1930 published a formal paper indicating that, when a fundamental signal included its harmonics of the 2nd (@-22db); 3rd(@-26db)' 4th (@-30db), 5th (@-37db) and the 6th (@-46db) then it is characteristically pure sound. In 1960 Toshiba set out to investigate this and arrived at the same conclusions. Interestingly enough, single ended tube (SETs) and (300B) type amplifiers often display spectral contents very close to these characteristics. OTLs included.

Another reason the OTL may be preferred is due to its characteristic high output impedance. This can lead to speaker matching issues for two reasons. Depending on a given speakers crossover this will have the effect of emphasizing the frequency band around the crossover point (anywhere from 330 to 1.5Khz). Emphasizing this frequency range has the effect of producing a warmer or more robust sound. Bob Carver tries to emulate this by adding resistance in the output of his amplifiers (current output). To some extend this may work however, this will be a constant ohmic value where-as, in the OTL such as an Atmasphere this will be a dynamicly changing output-Z. There will be some interaction differences here.

A possible third reason for the highly revered bloom from an OTL amp is the fact that, since it does have a relatively high output Z(3 to 7 ohms in the Atmasphere series) this causes speakers to be less damped. And, being less damped the speaker may very well become closer to being critically damped, which is generally the most desired condition for a particular driver. Generally, when one reads the response of a speaker driver the manufacturer usually specifies it when "critically damped". However, once installed in a cabinet or frame with associated crossover components we don't know the status of driver damping or the designer's intent with a particular system. So sometimes an amplifier with a higher Z-out will improve the overall percieved performance by more closly providing critical damping to the drivers and, of course it may not be advantagous due to the particular design. Hence speaker matching is imortant. Reportedly electrostatic speakers benefit from the highish output impedance due to damping effects where-as planar speakers such as Magnepans need a very low output Z to properly damp their panels. For the latter the auto-transformer will be needed to effect the low Z-out. And, being an auto-transformer there is not much loss in this device to worry about. It is not hindered by the same issues (leakage inductance, output-Z limitations, interwinding capacitance, etc. that affects push pull transformers. Any audible masking of effects are basically insignificant once the proper ratio is selected.

I hope I did not bore you here. Again I recommend that you try an OTL as, for whatever reason, it sure produces a voluptuously immediate soundstage that reeks of musicality and just might nail you.

This thread reminds me of SNL!

"Jane you ignorant slut" skit."

Funny!

Sorry I came down so hard on you Saxo.

Twl and Saxo, this reminds me of another thread. Thank you both for making me feel so at home. I love the passion of these kind of threads. After seeing the same questions asked over and over. Threads like this and a few others remind me of the old day's. I mean there's Tubegroover, Wellfed, Twl, Sean, and one if not my favorite, Trelja, all on the same thread. Ya gotta love it. i am sure we will be hearing some input from Jcbtubes once he gets back Sat.
Saxo, I do not mean this as criticism, but the Berning and Atmasphere are two different animals. At least in sound. I know the Berning and IMO, the Atmasphere ain't no Berning. I can also say the Berning ain't no Atmasphere. Great to see so many of the old regulars, not to mention the newer ones.

Yeah Brulee, I also love the passion and feel it very keenly for this product.

The thing that many philes will overlook with the zotl amps is that they are as small and lightweight as they are and will never be in the running in the beauty queen sweepstakes. There really isn't any marketing so they are word of mouth products. The one thing indisputable regardless of who will attempt to dispute it with me is that this is a cutting edge design sonically and technically, a real tour de force product. I would love to do a blind test with this amp and anything within its power range for a head to head and leave the bs at the door and THEN see what the results might be without visual, price, and other prejudicial impressions muddying up the waters.

I have read comments from others that it was a good performer in its price range, I say balderdash, it is a great performer in any price range within the limits of its power and the requirements of the speakers it might be used with. I just want to set the record straight on that and tell all what I REALLY think. This is not to disparage any other amplifier out there including Atmas-phere, Joule, Tenor, Lamms etc. but to say the Berning in the right system is in this league of component if not the best choice in a particular application.

Yes, I have heard all the above products I mention although admittedly not in a familiar system, I can only use my own as a benchmark.

PS and Romy, if there is any thing of importance that you would add you are welcome but if you just want to disparage (Atmas-phere and others) who have only been in business for over 20 years making great products, just check it at the door and tell us what you DO like, no one gives a damn what you don't.