Which one to choose between two 80K$ tube amps?

What makes the David Berning amp so special?

The output section topology gets around the traditional limitations of conventional transformers and so allows much wider bandwidth from the output section, regardless of power output. If you are wanting single-ended, this is arguably the best way to go. If you want a bit more power its especially useful, as the traditional issues that limit SET power and bandwidth simply don't exist.

It might be more accurate to call it 'Radio Frequency coupling'. The technique has produced IMO some of the best tube amplifiers made.

I have to admit I find this puzzling. Western Electric used to be the standard fare in movie theatres and the like, but their gear was supersceded by Altec, who had much greater performance and obviously better sound.

Its a simple fact that the distortion a horn may or may not have depends directly on how well the horn is formed along the ideal curves for it. There are now horns that have been built with these curves computer optimized, so they sound for more realistic.


I am very aware of how tricky it can be to set up a room as I have showed at many shows (we were 4 doors down from your friend's room). But I should point out he's had that room for several years and should know at this point how to set it up.


I get the part about jazz vocals sounding 'spooky' because they sound like they are right in front of you.  But that is the goal of stereo in general, and many speakers can convey that quality of 'spooky' insofar as images floating in space is concerned! I'd be a bit chagrined if I could not evoke that quality from my system!

One of my friend is the owner of Silbatone who display his vintage horn in Munich high end show.

@shkong78
I've heard that system in Munich in two different years. I liked it a lot. But having also heard the Classic Audio Loudspeakers, I would go with the latter in a heartbeat. Your friend's system was inordinately complex, somewhat diffuse for centerfill, and lacking the frequency extremes (in spite of the Altec-based subwoofer). Despite that it was one of the more interesting systems I saw at the show and I took a lot of photos. If you want it for the shear size and impressiveness of how a system that old that can sound that good, I can see that.


But if you simply want something that sounds the best it can for the money then I would look elsewhere.

@shkong78  If you are looking for a speaker that will work with lower powered amps, one you might want to consider is the Classic Audio Loudspeakers Hartsfield (reproduction). John Wolff has done a lot to improve the speaker since it ceased production, with better drivers, better crossover, sturdier cabinet, field coil operation and so on.

The Western Electric stuff is collectable and classic, but does not compete with modern computer-optimized horns. It was state of the art in its day but that was before World War 2. If you really want to get the most out of your amplifier, you won't be doing it justice with a vintage horn that old!! 


The WE300bs are excellent- that was back when the only game in town was tubes and they had to be right; they were often placed in service as line amplifiers for the phone company, and had to hold up. Some were even sunk in the ocean embedded into the inter-continental telephone trunk cables!

explains (to some extent anyway)  what/why I heard differently between my SET (class A triode 300b) and my 100 watt push pull( class A/B pentode tubed 6550) amplifiers. Some degree of 5th harmonic distortion presence.

Yes- nearly any amp along those lines will have some of that sound. But of course its more complicated than that- if the amp uses feedback, if its ultralinear or not, if its using triodes and so on. I'm not a fan of interstage transformers but if used in a fully differential topology even then you still get the 3rd harmonic without that pesky 5th showing up as much. You'd think by the application of feedback that you could erase that signature, but in almost any tube amp you simply can't put in enough feedback to pull it off (too many timing constants, especially if transformers are involved).

But, is 3rd order harmonic distortion as easily/naturally tolerated by the human ear as is 2nd order harmonic distortion which is quite well tolerated. Some would say that in fact 2nd order Harmonic distortion is congruent with human hearing.

@charles1dad 
The short answer is 'yes'. The ear treats both *exactly* the same. What *does not work* is if the amp has low distortion, but the distortion it has is mostly higher ordered harmonics (5th and above). Such amps tend to sound bright and harsh, compared to an amplifier that has a predominate 2nd or 3rd. The reason that so many push-pull amps get docked for their sound as opposed to an SET is that when you combine a single-ended voltage amplifier with a push-pull output, that type of topology tends to produce a noticeable 5th harmonic, which makes the amp less musical.


The only way I've found to get around that is to avoid that sort of topology- either go entirely single-ended and get that 2nd harmonic or go entirely fully differential and get a 3rd harmonic (although at about 1/10th the level that the 2nd shows up in a single-ended circuit). Since the ear is relatively insensitive to either other than contributing to 'warmth', 'body' and the like, this seems to be the way to go since you can't put enough feedback on a tube amp to really tame the distortion properly (or most solid state amps for that matter)- you wind up just making it brighter and harsher.

@charles1dad The Berning amplifier in question can run feedback or none; being SET its distortion signature is based on a quadratic nonlinearity (2nd harmonic). In order to have a cubic nonlinearity (based on 3rd harmonic) the amp has to be entirely differential from input to output.

The ear treats both the 2nd and 3rd the same way (contributes to 'warmth' and 'richness') but in general an amplifier with a predominate 3rd will have considerably less overall distortion (typically 1/10th) than one based on the 2nd, and as the distortion order is increased, the product falls off faster. This is especially beneficial because the ear is so sensitive to the higher ordered harmonics.


The advantage of the Berning amplifier over a traditional SET is that the output transformer is not nearly as bandwidth limited and it does not have the saturation issues. So it can be made considerably higher power as well!

which of your Atma-sphere amps would you recommend to compete with the Berning at this level and what would be MSRP on that amp.  

@t

By your request, The M-60, base price is about 7700/pair, but I would have them fully optioned at which point they are about 10,400/pair.

@shkong78

Just to be clear, the Berning is not an OTL. 'OTL' is an acronym for 'Output TransfomerLess'; thus refers to an amplifier with neither output transformers or solid state devices in the output section and the Berning has both (see the patent). It is however a brilliant amplifier (David is one of the top designers in high end audio IMO), and IMO its a no-brainer over the Jadis if you have speakers efficient enough as it sounds like you do.

Now you might want to try a real OTL; This is the kind of tube amplifier that employs only tubes with no output transformer or semiconductors in order to drive the loudspeaker. Traditionally for the last 60 years OTLs have been the most transparent amplifiers made. They also work great on high efficiency loudspeakers (my speakers at home are 98dB).


Rick had David design that amplifier specifically so Rick could market it exclusively (I've known Rick since way back when he was a salesman for 3M here in town). Its one of the better tube amps money can buy, but it has competition that is a lot less expensive- with your budget cheap enough you could afford both. IIRC the Berning amp also uses a specialty Elrog power tube that Rick is having made just for him. High end audio is all about intention rather than price :)