SET 45 Amp Driving Dynamic Speakers

Hi Larry,
There could be a few newbies to High End audio who begin with SETs  (admittedly I have not done a survey) . As you correctly acknowledge it more often tends to be very experienced listeners where SET is an endpoint destination . Again you correctly note the barrier to sucessful adaptation,  simple circuit but high quality parts/implementation are mandatory. The lower quality niche of SET will more likely fail to impress with their poor transformers and power supplies. Finally proper speaker match takes some knowledge and time. It's worth the effort in my opinion. 

Larry I respect Mapman's insights and experiences.  He has found much satisfaction with his class D amplifiers and I sincerely congratulate him.  My exposure and listening to class D experiences are parallel to yours , there's just something missing that leaves me unfulfilled.  As we both recognize these are simply individual impressions,  no doubt that there are many happy users of these efficient amplifiers. I don't question Mapman's  contentment by any means. I know what musically touches me but appreciate we all choose our individual paths. 
Charles, 

Larryi the Class D amps I own and have settled with currently are Bel Canto ref1000m in my main system and C5i integrated in my smaller setup.   Both are simply wonderful devices.  

Id like to add a third system built around either SET or OTL amps but space is limited.  

My experience is similar to Charles. I have Zu Definition 4s (reported to be 101db sensitive) and an Ancient Audio 300b SET. The Def 4s have their own integrated "subwoofer module."   Recently, the tube amp required servicing; and I used a back-up 80 watt SS amp for a few weeks. It was OK, but lifeless compared to the SET. This was most noticeable when I re-inserted the 300b SET tube amp last Thursday. Curiously, I did not have to adjust my usual pre-amp volume setting to "accommodate" for the higher output of the SS amp. I listen to almost everything: classical - both chamber and full-orchestra and chorus, jazz, classical rock, female vocals, etc. It did not matter; everything sounded better with the low-powered SET.

Inna and Charles,  I've experienced some really engaging conversations with fellow audiophiles, discussing everything from the flow of electrons to the flow of notes.  The fun part comes when I tell them I don't own a table.   Suddenly, they look at me as if I have giant lobsters crawling out of my ears.  I do love vinyl, but I don't really like the work and frustration.  I love what vinyl can do so well, but I also like what really good digital can do well.   I have an extensive digital library and really have no desire to go back to vinyl.  That is no more likely than going back to SS amplification having enjoyed a really good 300B SET design.  I think Charles and I are in a good place.  Call us crazy if you want. 

If this shows up as a duplicate post, please ignore. . . 

My experience is similar to Charles. I have 101db efficient Zu Definition 4 speakers driven by an Ancient Audio 300b SET. Recently, the Ancient Audio amp required servicing; and I substituted an 80 watt per channel SS amp for a few weeks. The difference was noticeable, especially when I reinserted the SET tube amp. While listenable, the SS amp was lifeless and lacked tonal depth and immediacy by comparison. One curiosity (and I would be interesting in some opinions); I used the same, midpoint volume control setting on the pre-amp for both the SS and tube amps. The speakers are located at one end of a large (45' long x 16' high) open plan space; and I listen to a wide range or music from classical (chamber to full orchestra and chorus), jazz, classical rock, female vocals, etc. 

Gary