SET amps ?

Tubegroover,
Clio09 makes a good point, it really depends on your speaker's ease of drive (not just the sensitivity rating) room, music genre and listening levels.
His result with a 10 watt amp is similar to mine with an 8 watt amp.
I listen to predominantly jazz and big band and sound envelops my room (14×25×8 feet). When I do play classical, usually small-moderate scale it is really compelling and engrossing . Large scale orchestral music is quite good with my 94 db 14 ohm speakers. I won't claim that this is the ultimate set up for large scale orchestra but my point is it does provide a satisfying musical experience. The presentation is very resolved, delineated and lively emotionally.

I'd say the Coincident, Wavelength 300b (several versions available) and Clio09's amp would be worth a listen. Tubegroover, a 845 SET amp may be ideal if your music is mostly larger scale classical fare and high sound volume.
Charles, .

Goldeneraguy,
Thanks for the invitation to hear your system. At RMAF 2011 I heard the Tron electronics driving a horn speaker in the High Water Audio room and it was one the very best rooms I heard there.

I have been quite impressed with the Horning systems set up by High Water at several shows. They were driven by top of the line Tron amps and Thoress amplification. This is a very dynamic, and immediate sounding system but Horning manages to tame the midrange peakiness I would have otherwise expected from the Lowther-based midrange driver. But, I would guess that that kind of midrange speed and detail makes this a VERY picky system when it comes to amplification.

I agree with Charles1dad that ease of driving is particularly important. I think it is much more important to matching with tube gear than efficiency. I heard low-powered amps on a pair of original 15 ohm Rogers 3/5A speakers sound wonderful in a quite large listening room. Those are something like 83 db/w efficient, but at 15 ohms nominal impedance, very easy to drive. A lot of fairly efficient speakers, like Wilson speakers, seem to be particularly challenging to lower powered tube gear because they have a load characteristic that is not suited to such amps.

Larryi,
I believe that the Horning is successful using the Lowther as a wide band
midrange driver rather than stretching it to the very upper frequencies as a
"full range" driver (they also wisely removed the whizzer cone).
Larry I truly believe that high impedance speaker loads are absolutely
advantageous for SET amps and lower power tube amps in general.

It often seems as though my amplifier is just coasting driving my 14 ohm
speakers. I definitely can relate to your example of the Rogers 3/5A
characteristics with low powered tube amplifiers.
Charles,

Well I would definitely agree that a higher impedance load particularly for a tube amp will always be advantageous. I am aware that some folks use low powered SET amplifiers with the DeCapos but I'm not convinced that it will suit my needs for my listening tastes but sure would like to try a good one that might work, which is why I asked you your thoughts. Often times people that gravitate towards these amplifiers tend to listen to smaller scale music, at least this SEEMS to be the case to me.

Charles I would like to further comment on the example I gave you above concerning the 845 integrated. This amplifier uses 2 845s per channel for a total of 4 and puts out 35 watts. I'm not too sure about the class of operation and feedback used but what I noted about it and virtually all SETs I've heard relative to the better PP and OTLs is a tendency to get a bit thick and confused during complex, dynamic music. I wouldn't begin to suggest that this is the case for all these designs but it really is my impression over the years from that first time 20 years ago when I heard a small Cary integrated with the 211 tube driving Swann speakers to everything since. Yes I suppose I am a bit prejudiced against SETs in general but only based on my personal experience. I don't necessarily believe they ALL sound like this since I haven't begun to hear everything out there. I seriously doubt I've heard the best of this breed.

I have recently become aware of a prototype 845 based design by David Berning that is pure Class A, zero feedback and 50 watts using his zotl technology. I don't know if and when it will be marketed but this seems to me a design that could meld the best attributes of both SET and OTL amplifiers. My guess is that it still wouldn't be rich enough for some tastes which seemed to be the case with his Seigfried.