Atmasphere, we're definately on the same page as far as the system-matching aspect of different amplifiers being optimum for different loudspeakers, especially when comparing among various speakers and amplifiers that use very different technologies and design approaches. But, er, well take this statement:

Power Theory (or Power Paradigm) is where the amp seeks to make constant power into all loads. It will not succeed, but that is the goal. The Dynaco ST-70 is a good example, 4,8,16 ohms its 35 watts. Our own MA-2 is another, 4,8,16 ohm 220 watts. Some transistor amps fall into this category.

I'm sorry, but the reasons why a ST-70 and a MA-2 both have constant power ratings into 4,8, and 16 ohms are completely different from each other! Further, a ST-70 has a much lower output impedance than that rated for the MA-2, and thus will interact with the loudspeaker impedance to a much different degree.

To use your B&W 802 example . . . according to Stereophile's measurements, this loudspeaker varies from a low of about 3 ohms in the mid-bass, with a peak of over 21 ohms in the midrange. Looking at my notes from the last time I measured a stock ST-70, it had an output impedance of about half an ohm over most of the audioband, from the 8-ohm tap . . . so I'll take an educated guess and assume it's about 0.29 ohms from the 4-ohm tap, which is what you would use for the 802.

So a ST-70 driving a B&W 802 would thus have about a 0.68dB response peak in the midrange due to the interaction of the amplifier output impedance and the speaker's impedance curve. For comparison, a hypothetical traditional solid-state amplifier (0.05 ohm output impedance) would have a 0.12dB response variation. But the MA-2 (published 1.75 ohms output impedance) would have a peak of 2.3dB! And for the MA-1 and M-60, the deviation is even greater . . . 4.04dB and 5.93dB respectively.

Now we're in complete agreement that the B&W 802 is a bit of an extreme case, and also that it's a poor match to an Atma-Sphere amp. And I'm not suggesting this is an inherently bad thing about Atma-Sphere amps (just a "system misapplication" if you will), or that the Dyna is a stellar match either . . . I'm personally a fan of the ST-70 but am also very familiar with its myriad shortcomings. But the ST-70 can hardly be considered a "Power Paradigm" amplifier because of its comparatively low output impedance.

Let me again re-iterate my original point: The suitability of an amplifier for driving a particular speaker simply CANNOT be inferred from looking at its clipping-power ratings into various load impedances! Ever. Period. It's output impedance that makes the difference.

Two secondary points: First, historically, there has been no Paradigm Shift - common practice loudspeaker design has ALWAYS been about constant voltage with frequency . . . as most vintage hi-fi tube amplifiers (such as the ST-70) have low output impedances, especially when compared to loudspeaker impedance curves of the day. Second, this is NOT a tube/transistor thing . . . there are many examples of solid-state amps with high output impedances in addition to tube amps with low output impedances.

Incidentally I actually commend Atma-Sphere for publishing their output-impedance specifications . . .