Dear Steve Williams: Ignorance is the mother of all wars and your level ( with all respect ) is to high, either on the tube amp output impedance/speaker impedance subject that you just can't understand. You showed in this thread that can't understand that the tube amps ( including the very well respected Atmasphere. ) mated with an speaker works as an out of control grafic equalizer. No one, including R.Karsten whom I respect a lot and whom in other forums we already discussed in deep that impedance overall subject, can't change that because the Ohm Law. Period.
In the other side your ignorance level gone in your imagination: I never designed or manufactured any single amplifier, period.
I'm posting in this forum as a real MUSIC lover. I can't say the same from you and other gentlemans here.
I hope some day you can understand what means: right and what means wrong. Till then!
Regards and enjoy the music,
R.
Raul, I have repeatedly offered a link to why your comment about Ohm's Law and 'graphic equalizer' is incorrect. Here it is again:
http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php
In addition, we humans have an ear/brain system that follows certain perceptual rules, which are surprisingly similar over the entire population. One of the most important is that we detect volume not by the fundamental tone but by the odd ordered harmonics of that tone. Anything that increases odd ordered harmonic distortion by even trace amounts is audible to our ears as a brightness and a hardness. This is why two amps can have the same bandwidth but one will sound bright and the other will not.
In addition Dr Herbert Melchur of Nobel Prize fame has shown that the ear/brain system has a set of tipping points. For example the brain will translate most forms of distortion into tonality. Lower orders contribute to warmth or lushness, higher orders to brightness. So one of the tipping points is where distortion as tonality is favored over actual frequency response errors or lack thereof. In essence, a perfectly flat system can sound as if a graphic EQ system has been applied on this account! In addition the brain has a method of analyzing the acoustic environment and compensating for it. This is important because no room/speaker combination will yield an actual flat character. What the take-away message here is that it is often more important to have low distortion of the kinds that the ear cares about, more so than it is to express actual flat frequency response.
One would think that understanding how the ear/brain system perceives sound would be paramount to being able to build an audio system that sounds real to the human ear. But I find that for the most part, the audio industry prefers to ignore the research of the last 45 years and collectively buries its head in the sand. This is certainly one of the reasons we have the objectivist/subjectivist debate raging on for decades. The numbers don't speak to how our ears work.
But as I mentioned before, one does not have to know anything about the sound of tubes, anything technical at all. All one has to know is that for some reason, tubes are still here long after being declared obsolete, and there are still a lot of manufacturers that use them, for high end audio, for musical instruments and for the recording studio. By comparison, side valves in internal combustion engines were declared obsolete a few years before that happened to the vaccum tube. But no-one makes a side valve motor nor has anyone done so since the 1950s.
In short, the vaccum tube failed to be inferior to the succeeding art, and thus is still around. That simple fact is more telling than any technical argument.
Edit: Tubes have been 'obsolete' now for longer than they were the only game in town, IOW for most of their history of use they have been considered obsolete. I wonder how many other technologies that are 'obsolete' continue to be used, not just for the sake of charm but for the actual improved performance? Not many, that is for sure so I think the term 'obsolete' is not really the right descriptor at all.