High-end amplifier clarification?

Figuring out what makes any product a 'high end audio' product has long been a vexxing subject. In thinking about this over the last 20 years, the best answer I have ever been able to come up with is 'intention'. So in this regard I think I agree with Phaelon the most, although most everyone here has made points that I consider valid.

But even with the idea of intention, products occasionally appear in the mainstream that are so good they qualify despite their humble origins. Radio Shack has produced a few of these, for example their Linaeum speakers from about 10-15 years ago. They were inexpensive but got good reviews. But for the most part, the intention of the designer will be the primary aspect we are looking for.

Weseixas, so if an amplifier that can't drive 2 ohms but otherwise sounds better than one that can, its still mid-fi? So sound has nothing to do with high end or mid fi?

Sound is very subjective, one man's euphoria is another' anathema. An amplifiers job is that of an voltage source, expensive high end amplifiers that cannot replicate such, is well ................

A Pretender.

Weseixas, so you exclude Nelson Pass?? Gamut?? Shindo?? Kondo?? Lamm?? VAC?? Sorry. Your model does not hold up. BTW, you might be interested in this;

http://vintagefisher.com/vintage-fisher-55-a-tube-power-amp-monobloc-55a/

What we see is a Fisher 55-A mono amplifier. The knob on the lower right hand side is the Z-Matic knob, which is a variable feedback control. It is labeled: "Constant Voltage" on the fully counterclockwise position, "Constant Power" at 12 o'clock, and "Constant Current" at fully clockwise.

You seemed to accuse me of 'pseudo science' on another thread recently; I just thought you should see this so that you would know that I did not make something up. And also, you can see that tube amplifiers are capable of being voltage sources. The Wolcott is an example of that.

However now that you see that I *did not* make this up, and that a feedback control is having something to do with this on the Fisher, then you will see that my comments about negative feedback being something that is often part of the Voltage Paradigm (http://www.atma-sphere.com/papers/paradigm_paper2.html ) is not made up either.

And it is a fact, borne out of real science, that there is a price paid for the inclusion of negative feedback in most amplifiers- that of increased odd ordered harmonic distortion, which is shown to be unpleasant to the human ear.

So the bottom line is that it is **intention** that defines what a high end amplifier is. It is certainly not the ability to drive 2 ohms, as quite often that ability means that the amplifier might not sound like real music, and therefore neither can the speaker being thus driven. Some designers want to see their equipment sound better than that. You see? Its intention, and nothing else.

Now just so we are clear, it may be the intention of the designer that the amp *should* drive a 2 ohm load as a voltage source. That's fine- it still falls under the definition of intention.

Weseixas, some of the best speakers I have heard are much more than 4 ohms.

Just so you know, our amps can do a 20 Hz square wave with no measurable square wave tilt, which will not be the case with an amplifier that cuts off at 10Hz.

The point of this thread I thought was all about what made an amplifier high end. To that regard, I hate to say it but its a simple fact that the intention of the designer is what fulfills this definition, not the actual sound produced! Now you are welcome to your opinion, but I think as you look at this subject, in due time you will see that a certain ability in an amplifier is not sufficient to call it high end without other factors.

Now you say I am defending my topology, and there is some truth in that, but at the same time I am also defending others, for example those that were on my list in my last post. In each case, a high end amplifier manufacturer was named, but their 2 ohms response is likely limited.

Now I realize that the whole Voltage/Power paradigm thing is a problem for you. I used the term 'paradigm' for a reason: A paradigm exists when anything outside that platform of thought is simply discounted as 'not right', 'bogus', 'non existent', 'pseudo science', etc.

Now I think you have also brought up a different subject, which is 'what is the State of the Art (SOTA)' which is a different question from 'what is high end?' We can easily see that there is a difference- if the manufacturer of your amplifier has another model that is built with similar ideals, are you going to tell me one is high end and the other is not?

It may be as well a question that is equally difficult to answer- it took me 15-20 years to have a really good answer to the issue of high end.

But I can say this: what would define State of the Art? The ability to drive 2 ohms? In the absence of the ability to also sound like real music, the answer there is no. IOW, the ability to sound like real music has got to be in the cards, because it is the music that it is all about.

Now if you could build an amplifier that was a voltage source, that was also lacking in the odd ordered harmonics that color such amplifiers, I would be down with that in a heartbeat. I don't like brightness- to me its a more sinful coloration than the traditional 'tube' sound (by that I mean the 2nd harmonic, which BTW is lacking in our gear as it is fully differential). So there are aspects of this that seem to point at taste.

Weseixas, We did a few Stereophile shows but none of them were in '94. There may have been someone there using one of our amps though.

These days at home I use a speaker that is 16 ohms and goes to 20Hz. It uses field coil drivers with beryllium domes for the midrange drivers. There are no breakup in the speakers anywhere in the audio band, so they are quite smooth, very detailed and fast, owing to the fact that there is no magnetic sag in the magnetic field of the magnets- not unlike the way ESLs work. Clearly in its own way it expresses state of the art operation, even though it is not a low impedance planar or the like.

There are not a lot of published specs of our amps that are the result of independent measurement. One of the bigger problems we have run into is the fact that output of the amplifier floats, and so if the scope or analyzer used on the amp has a ground connection into the AC wall power, the result is that one of the speaker terminals will be at ground. This causes the amplifier to have high distortion and low power due to the resulting unequal drive of the power tubes in this condition. This was a problem with the Soundstage.com tests done about 10 years ago. In that test the amp only made about 100 watts- not the 140 that it did when we got the amp back from them and double-checked the results.

About nine years before that, an engineer in Salt Lake City sent us the results of a test that he did on one of our early MA-2s. That amp had a feedback switch that allowed that amp to run 8 db of feedback. The output impedance that resulted was under 0.5ohms. You can make a voltage source out of an OTL IOW, but to my ears it never sounded right when you engaged the feedback. I did notice that there were certain speakers that needed the feedback, but I found that if the speaker needed it- there was no way it would sound as good compared to a speaker that did not need the feedback.

That precipitated the investigation into the why of that matter, but I really did not feel comfortable in explaining the results of that investigation until about 5 years ago.