The SET amp question.

Unlike some of the responses, I cannot lend further technical explanations, but I can share some impressions of how single ended triode (yes, the "T" is in place in my experiences I'm sharing here) distinguish themselves in presenting music. I have been listening with a pair of 300B SET amps for about nine years now. I've strayed but always seem to come back to them because they seem to suit the music I prefer and the way I prefer to hear it. These impressions are my own and YMMV. SET seem to excel to extremes in breathing life into vocals and more sparse and simple instrumental arrangements. When the music starts to get more complex and layered and dynamic, SET can be bested by other forms of amplification, though it does OK for the most part. If you listen to a whole lot of music of that latter type, you might be disappointed overall. You most certainly will not be disappointed if your tastes run to the former (more simple, sparse arrangements). IMO, No other form of amplification seems to breath life and presence into music the way SET does at its best. The term "Living Presence" comes to mind. They excel at soundstaging - creating an illusion of a three dimensional space. Your sensitive speakers may indeed be well suited, but sensitivity is only part of the story. A flat impedance curve will also go a long way towards making the combination work out well. SET amps generally will not have much authority in the bass, nor as much sparkle the highs, but MY OH MY they do midrange, where 90% of the music is at, like nobody's business! A cheap introduction to the power of SET can be had in spades with the Wright 3.5 amps that use 2A3 tubes. I've seen them frequently on the used market for $800-900 for a pair of monoblocks. They are all about midrange, but that midrange is like crack to a junkie if you appreciate it. They are SET at the extreme end of the spectrum. Again, if you are a hard rocker or into heavy orchestral music or opera...you get the picture...you probably should look elsewhere. That's just my opinion. I keep coming back to SET myself, but I would not call it a versatile performer. It is an eccentric...more of a one-trick pony than a crowd pleaser for the masses. Another intoxicating alternative which has more potential for a more linear presentation, and is more versatile at presenting a wider range of musical preferences would be OTL amps, such as the excellent offerings by Atmasphere.

One further note on SET - I think pairing the amp off with the right speakers is so much more critical with SET because the wrong combination is just going to be a waste of money and effort, and can be very frustrating in that regard. You may want to seek out some opinions from folks who have paired off the same speakers you have with SET amps or SE amps to focus in on the better potential combinations.

Marco

The only thing I would add is that different tubes have different sounds, over and above how they are applied. To me, 300B's give the classic mid range brilliance, but are less good at freqency extremes. The 845, my favourite, is more neutral and more powerful, will tend to give a few more watts. My 845 puts out 22watts and will drive my speakers at 89db sensitivity, with ease. They do still lack the base grip of SS designs, I will happily sacrifice that.

At 110 db/w, you would have the luxury of being able to use just about ANY kind of SET. I would certainly consider 45s and 2a3s, because the higher power of 300bs and 845s and 211s would probably not be needed. It is a matter of taste, but these may be, to you, preferable to the other, more powerful tubes.

Everyone has done a good job explaining the differences. As for a recommendation of brands, Don Garbers "Fi X" is a great amp to try out. I think with your speakers, it will be a great match.

I would also put the late John Hogan SET's on your short list. I've owned two (one was a 2A3 & 45 and the other that I still own is a 300B), both bought without hearing first, and can only be described as AMAZING! I used both with my 99DB and 101DB Klipsch speakers.

As has been said, it's a magical midrange that just has to heard.