High Current / Low Current / No Current ??????

Damping factor is an old myth that has many advocates. That is what D_edwards is talking about above.

The simple fact of the matter is that damping factor has marginal effect on most drivers. Yet, we hear differences- what are they about?? What is happening is that in a 'low damping factor' amplifier (IOW 'low current') as the impedance of the load gets closer to that of the output impedance of the amplifier, the amplifier will make more distortion. It is important to understand that this type of distortion occurs without the amp clipping.

As audiophiles we have developed words for this type of (harmonic) distortion. A moderate amount of distortion is described as 'bloom' or 'warmth', excessive amounts are described as 'muddy' as in 'muddy bass' or as in 'loss of control'.

What is important here is that the driver is not contributing to this, these are artifacts of the amplifier.

Magnaplanars have always sounded their best with tubes. The reason that transistors get used with Maggies is usually power, not control. It is quite expensive to develop power with tubes and Magnaplanars (particularly older ones), require a lot of power to get high volumes as their magnets are located on only one side of the driver.

"Damping factor is an old myth that has many advocates."

All I have to say to this is, you can't measure a myth.

"The simple fact of the matter is that damping factor has marginal effect on most drivers."

In your opinion. Since your amplifiers have little I would expect little effect compared to the SS monsters. When you're dealing with a hobby that deals with minutiae I would say the effect of "damping factor" is very significant especially on dynamic drivers. That is , it is measurably significant.

"What is important here is that the driver is not contributing to this, these are artifacts of the amplifier."

? The amplifier and the speaker are one circuit, so the speaker makes its contribution also. The Halcro amplifiers
are perfect amplifiers from a technical standpoint put since speakers aren't close to taking advantage of this perfection, they suffer due to the speakers contributions.
In a sense I agree with what you're saying but this Harmonic distortion can be had in solid state amplifiers too.

"Magnaplanars have always sounded their best with tubes."

In your opinion. I think Classe & YBA and Ayre amplifiers make it rough going for tubes especially when you consider the price point one may be seeking an amplifier for the 1.6's.

I would be curious to which speakers you believe don't sound better with tubes. Can we agree that would be a short list of speakers you don't like so you don't care what amplifier is on them? (hope that's not too direct a question or statement)

I heard the $15,000 Warner Imaging amplifiers easily best your $30K amplifiers on Sound Lab U1's, I consider that a defeat on your home court. Admittedly your amplifiers embarrassed the Wolcotts, Lamm's and Pass X600's amplifiers so don't fret. I like your amplifiers, if I had to buy tubes they would be the ones. But I don't see why you have to run around this issue. Tubes have limitations and they have advantages. Same with solid state.

Why don't you say that the propensity for Magneplanars drivers to exhibit an overshoot upon higher musical input means you may want to seek an amplifier that has a slower rise time (output transformed amps), something the Atmospheres do not exhibit or have. You may want a harmonically rich amplifier like a Music Reference RM-200 or a Classe CA-200. This will help the Maggies stay linear and provide you with a smoother sound. My (the atma-sphere) affordable amplifiers are low powered and this will not press the Maggies as hard dynamically and will net the same result of a fuller richer sound do to the higher harmonic content in my designs but you my be lacking in total volume(output) if your room is moderately large or larger, especially with the MG12's, you'll need more power.

Simply trying to make a solid state advantage dissappear by saying the price of high current is poorer sound only makes your amplifiers victim to the same statement. Since your amplifiers probably have some of the highest current output of tube amplifiers on the market. Which is why they are so good, so good infact that I make exception when I talk about tubes for your designs and mainly your designs (Atma-sphere) alone.

"The reason that transistors get used with Maggies is usually power, not control."

In the end I generally agree, most solid state amplifiers emphasize the technical weakness of the Maggies. But not all. And Magneplanar demand a balance of power and harmonics which tubes get left out due to the comment below. Again reiterating Atma's comment about price.

Magneplanar is a cheap speaker for the performance, this is what creates the amplifier conundrum.

Output impedance is what damping factor is about, IOW it is the ratio between the output impedance and 8 ohms. However measurable, it has hardly any effect on the loudspeaker, unless we are to believe that a speaker displaced is to stay that way when the voltage is removed. Of course that notion is fanciful- the speaker returns to rest. Damping caused by the amp has no effect as the amp *at any time* is producing a voltage that causes the speaker to displace to a specific location with respect to its motor (magnet or ES field). Thus: Damping factor is a popular myth, an urban legend that is made up.

As far as Halcros being perfect?? Sorry, but they are far from it! I can run a demo anytime to dispell *that* and did so at THE Show in Las Vegas, where they were two doors down with the same speakers we were running. The differences were thus very apparent.

It is a rare speaker that does not sound better with tubes, although some will exhibit compromise in some areas (Which are always issues of load impedance). IOW tubes are better sounding in general than transistors in general.

It sounds like you need to hear a set of the MA-2 MkIIIs, which you did not hear when you made your comparison. You must not have played material with bass, else you would have noticed that the Warners weren't making what they should have on the Sound Labs. I suspect you like things brighter than I do, which the Warners would have been. Sound Labs do that with transistors. Its they way they work.

I think you do not understand the 'current issue' but don't this is not an attack- this issue is generally misunderstood :/

Here is what is happening in audio today: There are 2 paradigms that are in conflict. One is the Voltage Paradigm and the other is the Power Paradigm. In the VP, it is assumed that the only thing that is important to measure in amp and speaker specs are voltages. This is the reigning paradigm. OTOH the PP assumes that it is important to measure power response, not just voltage. In this camp, (knowingly or not) are ESLs, magnetic planars, horns, single driver speakers and a variety of box speakers; all which sound better if used with an amp that will make the same power regardless of impedance. SETs and other zero-feedback amps fall into this camp. SO- our amps may have 'current', but only in the context of making Power, without the price of feedback, which increases odd-ordered harmonic content so objectionable to humans.

Magnaplanars can have amazing performance for the price so it is important to winnow that out of them. If you need shear volume, you may have to go solid state, but for nearly everything else, tubes rule.

Matti Otala....the guy who did all the work on "TIM" wrote a paper for the AES (and believe it or not.......they accepted it! Or course, this was before he got under their very thin skin with his TIM work.)

Anyway....he showed by some complex mathematical mumbo-jumbo that the drive requirements for a speaker can actually be lower than its DC resistance would dictate.

Bottom line is.........in your case.........Maggies do not exhibit this phenomenon, as cone drivers in boxes do.

Low drive impedance may "grab" the panels better, but there is not necessarily a direct correlation between output Z and drive current.

Make any sense to you????