Double down, good or bad?

Unsound, I've heard a set of our MA-1s driving the old Full Ranges, which were one ohm (we used a set of autoformers that had one ohm taps). There is an old TAS review which mentions that from the early 90s as the speakers were owned by a TAS reveiwer.

Seems to me Paul Bolin used Duetta Signatures.

Best Thanksgiving and holiday wishes to all . . .

I am not discussing clipping at all, nor do I see clipping power as interchangeable with output impedance- no idea where you got that.

Atmasphere, here's where I got that . . . quoting from your "white paper" that started this whole thread:

Let's say you have a high quality 150/channel transistor amp. 150 watts into 8 ohms, a reasonable amount of power, but if you have a four Ohm speaker its 300 watts. Nice. Into 2 Ohms, if the amp doesn't blow up or current limit, 600 watts. So what does the amp produce driving 16 Ohms? 75 watts. Into 32 Ohms its only 35 watts! . . .

. . . This is what the right OTL can do into these impedances: 150 watts into 8 ohms, 145 into four (less than 1/2db difference), about 80 watts into 2 ohms, but into 16 we have 149 watts, into 32 ohms 145 watts . . .

Are you not, in all the wattages above, referring to the maximum power available, BEFORE CLIPPING, into various resistive load impedances? If not, to what are you referring? And from these specifications, you conclude:

Thus there is no way that a transistor amp can be described as linear if it is subject to these problems and that is one of the reasons why transistor amps produce so many amusical colorations. The reason has to do with the vanishingly small output impedance of the transistor amp

In your Power Paradigm "white paper", the same conclusions are made:

Let's say you have a high quality 150/channel transistor amp. 150 watts into 8 ohms, a reasonable amount of power, but if you have a four Ohm speaker its 300 watts. Nice. Into 2 Ohms, if the amp doesn't blow up or current limit, 600 watts. So what does the amp produce driving 16 Ohms? 75 watts. Into 32 Ohms its only 35 watts! This could result in serious problems were the speaker a typical electrostatic, where such impedances are common in the bass frequencies. This explains why transistor amplifiers are usually such a poor match for electrostatic speakers.

No, these power ratings say absolutely NOTHING as to why an amplifier may be a good or a poor match for an electrostatic speaker. Or do you mean output impedance here as well?
Can you not see that you use the concepts of maximum clipping power and output impedance interchangibly, or you feel that one is an accurate indication of the other?

Kirkus, its clear to me that your perspective is that of the Voltage Paradigm

Actually, I don't feel personally polarized on any of these issues . . . I find it far more interesting to try to work to understand the actual correlations between circuit design, measured performance, and perceived quality of sound reproduction. And to this end, it seems obvious to me that factors such as output impedance, maximum power vs. load impedance, type of feedback employed, and circuit topology are best considered and analyzed individually, rather than as a group or belief system.

Ralph, sorry but to my mind that's cheating. Were the tube amps driving auto-transformers or Apogees?

Unsound, thanks for the link to the Threshold Stasis article. From the description given, there are two main differences between the Stasis circuit and a conventional solid-state amplifier.

First the output stage -- a standard bipolar emitter-follower output section can be thought of as using 100% local voltage feedback, purely a function of the transistors' exponential Vbe/Ic characteristic, which delivers very good linearity and low output impedance (even before global feedback) as a result of the bipolar transistor's high transconductance. It seems that the Stasis circuit instead uses local current feedback to effectively bootstrap the output transistors to the voltage amp, and its linearity and output impedance will be a result from the particulars of the "current sensing" circuit employed (which I assume to be quite effective).

The other main difference isn't so much a Stasis thing, but it's the fact they use FET transconductance voltage amps, rather than a bipolar transresistance voltage amp. This means there's a fraction of the raw open-loop gain available. According to the text, there's no overall feedback, so I'm not quite sure about the hows and whys of the differential input stage, but suffice it to say that a low-gain FET voltage amp is a symbiotic choice when paired with a low- or zero-global-feedback design.

But in terms of clipping, I think the overall output impedance is pretty low, so it should still behave very similarly to a conventional amplifier as far as "doubling-down" is concerned.