high power tube amps vs ss

05-10-13: Mattmiller
Efficiency and Sensitivity are words that get confused when talking about speakers.

That is true. But I don't think that the references to efficiency in several of the earlier posts represent unreasonable uses of the term.

Strictly speaking, speaker efficiency would be defined as acoustic power out vs. electrical power in. It would be expressed as a percentage, and would be a very small number for nearly all speakers. It would also be a number that is rarely specified, and that is not particularly helpful.

It is common, though (and reasonable, IMO), for the term "efficiency" to be used to refer to sound pressure level at a distance of 1 meter in response to an input of 1 watt. And for "sensitivity" to be used to refer to SPL at 1 meter in response to an input of 2.83 volts.

2.83 volts corresponds to 1 watt into 8 ohms. So for an 8 ohm speaker "efficiency," per that loose definition, and "sensitivity" would be numerically identical. For a 4 ohm speaker, efficiency per that definition would be 3 db less than sensitivity, since 2.83 volts into 4 ohms corresponds to 2 watts. That difference will have greater significance in the case of a tube amp than a solid state amp, because the power capability of a tube amp into 4 ohms will generally be similar to its capability into 8 ohms, while the power capability of a solid state amp into 4 ohms may be as much as twice its capability into 8 ohms.

On another note, in my previous post when I said:

Another point I would make is that IME a forte of tube amplification tends to be imaging and dimensionality. Although I have no basis upon which to be certain, my suspicion is that that is not a strong point of these speakers, and that potential benefit of tube amplification would likely be wasted on them.

it occurs to me that my wording could be taken more negatively than it was intended, due to my use of the word "wasted." To clarify, my intention was just to say that I suspect that the potential benefit that IMO tube amplification can often provide with respect to imaging and dimensionality would probably not be realized with AR9 speakers. One reason for that suspicion, in addition to its general configuration, is the comment in the review I linked to that the AR9 is designed to be placed close to the wall, which usually results in imaging being compromised to some degree.

Regards,
-- Al

Al . . . you're the best! Would you adopt me?? ;-')

My goodness! What's it gonna take to convince you guys?:(

In response to Mattmiller I agree there is something magical about a well executed 75wpc tube amp. Contrary to another post, I find many modern tubes quite good. In comparing NOS 6550 GE tubes, the Winged C had much better bass and none of the shrillness I find in the GE. The KT 120 is another fine tube. The Gold Lion Tubes have many fans. In response to the original post, connect with a local audio group and see who is willing to allow you to audition their gear or a dealer with a generous return policy. Jallen

Jallen,
When I was using a push pull 6550 amp the Winged-C served me well.Your suggestions for the OP are on the mark.