Scroll down a little and read the discussion at the second link.
Who knows the sonics as generally as you have given the Q and if you would like it? From a power point of view... can it be tried? The two links give a decent idea. What is the speaker's sensitivity and impedance?
I've talked to folks who are happy with much less power than indicated above but I think it's about right.
I use the Reference 3A De Capos with a pair of George Wright Mono8 (300B) mono blocks. The results are mixed. In my modestly proportioned listening space (18' x 13') there is never any amp clipping. The 92db speakers play plenty loud. I also love the gentler highs and the gorgeous midrange of this amp/speaker combination. Small ensembles and human voices are exquisite. Late night listening to choral works and jazz combos give me goose bumps.
The problem is the bass. This (maybe all) combination of a non-feedback amp and a vented speakers creates a wooly and ill-defined bass. For instance, I find it hard to distinguish the low notes on a bass violin, the walking bass on so many jazz, rock, and pop albums. The same speakers matched with a push-pull EL34 amp have thunderous bass (for a monitor, anyway) but of course the midrange suffers. Compromises, compromises. I switched from the 8ohm to the 4ohm tap on the amp and the added damping helped a bit, but I still miss the tight bass I know the De Capos can reproduce.
I have heard the Ref 3A de CAPOS with low powered SETs at shows, which are horrible conditions. However, based on that we took on the line.
We used to carry both JM Reynaud and Reference 3A, and we sell a lot of SET amps. We are very deliberate about which speakers we sell with SET so I'll jump in here...
JM Reynaud does not make any speakers that I have heard which run well on SET at all. Most of them need pretty big push pull - at least 50 wpc. for optimal performance. We had a pair of Twins and Trentes in here recently and even on 30 wpc. push pull they were closed down, had poor bass control, and it was clear that they needed more power. We spent a while trying to analyse the problem and couldn't come up with anything conclusive. The impedance of the JM Reynauds is fairly benign - but I think there is something capacitant in the crossover, and the woofer is definitely putting out a lot of back EMF. The result is that when the bass kicks in on the JM Reynaud's you end up with closed down mids and shrill highs. Forget SET with anything from JM Reynaud period. We found that they sounded quite nice on 70 wpc. push pull monoblocks, so I say 50 wpc. minimum and consider going closer to 100 wpc. if you wish to run JMR on tubes.
The de Capo's are a different story. They are what I call semi-SET friendly and definitely push pull friendly. Depending on your room size, listening levels, etc. you can sometimes get away with SET on the de Capo's. They are marketed as being extremely tube friendly and the marketing is somewhat exaggerated and embellished. Their impedance is fairly high and flat, and the sensitivity is reasonably high. But they have no crossover on the woofer so they put out Back EMF like crazy when you start thumping away on the woofer. This means that if you listen loud or are in a large room and must turn up the amp to fill the room with sound, you will start to run out of power very quickly as the amplifier sees lowering impedance as a result of Back EMF. For moderate listening levels in medium sized rooms you can get away with 300B's on de Capo's, and the combination will sound lovely as the de Capo's _do_ sound their best on tubes. I would never run them on any less power however, and if you listen a louder levels or have a bigger room (or listen to material with a lot of deep bass) you will want bigger SET (i.e. parallel or 845's, etc.) or quite possibly push pull.
Please understand that I am not dumping on either speaker - they are both fine examples of loudspeaker design and can be highly enjoyable if mated with the proper amp. I am simply offering our experiences with a variety of SET and push pull amps on these two speaker lines in the hopes that it will enable you to get the best sound should you choose either. We are very rigorous with speakers when we evaluate them on SET amps because we want to make sure customers are getting the most out of their investment.
How about a set of Lowther driver Lammhorns? About 100db efficient, and works great with 300B. No front loaded horn, only back loaded for bass augmentation. Great sound. No crossover. About $5k new.
My room is 11 x 13.6 x 8, plaster with cove ceiling, hardwood floor w/ plush carpet and pad. I sit in a relative nearfield (9ft from front plane of the speakers). I have heard two speakers with the Lowther driver, both homemade) and it sounded as if I would need to be somewhat farther away. Both speakers had an inner "fingernail on chalkboard" sound even though driven by 2A3s and 300Bs. Also, my Air Tight 300B is not the quietest amp around and I'd like to go no more efficient that 92db. However, I do want to thank every one for all info given, found everything very useful. My hat's off to Audiogoners once again! Any other suggestions of 90-92db (w/ stable impedance loads) speakers?
Tom: Not so fast as my experience has been quite the opposite from that of S. of Sound in regard to the Reynaud Twins.
I have owned the Twins for going on two years now and ran them for a year with an Audion Silver Night 300B Stereo SET in a room much larger than yours (see my system which is listed for the room details).
Bass was never a problem with this particular setup (the only problem being full scale classical @ higher/loud volumes, when the sound stage started to shrink/compress).
I once set this system up in our spare room (approx. 10' x 14') and in this application the combo handled all types of music @ any sane sound level (bass had impact as well as tonality).
I have also used a vintage Pilot 232 power amp (approx. 12 EL84 push/pull watts) and again no bass problems (a very nice/balanced sound, but lacking the depth of SET's).
The end result depends on the specific amp used (not the power rating), IMO. My 50 watt SS Musical Fidelity X-A1 amp displayed less bass control and depth than either of the tube amps mentioned above and the speakers never really opened up.
My current setup is not a good match (2A3's with the Twins), but this is temporary until I can afford another 300B amp for them (the Bottlehead gear will then be moved to the smaller room with different speakers).
Many of the Audio Note speakers would do the trick. I would suggest you contact Joe from JC Audio and get his advice.
These speakers are based on the old Snell design and have between 93db and 95db sensitivity with an easy amp load. They will work very well with 300b's.
They don't look like much which is why I believe they are often overlooked but they will outperform many speakers at much higher price points.
I've driven my JMR wins with a Cary SEI-300B and it worked extremely well on most music. In fact, I'd say it was jaw dropping - rich midrange, airy highs, and deep articulated bass. The most amazing vocals and acousic instruments that I have ever heard on my speakers. As mentioned above, can't be beat for small jazz, chamber music, quartets, etc. And it could go L-O-U-D.
Depending on the size of your room, musical taste, and how loud you like to listen it could be a match made in heaven.
The problem I found was that the Cary ran out of steam on complex passages. It was like the music collapsed inwards on itself. All bass whatsoever disappeared. Some knowledgeable SET fanatics told me that this was probably more a power supply problem of the amp than the low wattage.
You really need to hear the matchup for yourself before deciding. SET + Twins is a magical combination. Although, matching the JMR speakers with just about anything is great. Of course, I'm horribly biased :o)
Tom, just for reference, did you listen to Lowthers that were 1 year old or more? There have been major changes to the Lowther drivers in this past year. The model names remained the same. They have rolled the suspension surround inwards for smoother response, and have put a rolled edge on the whizzer cone to virtually eliminate the upper midrange anomalies known as "Lowther shout". It is a much more refined sounding speaker now. After about 200 hours of break-in these speakers are very fine sounding units. Perhaps another listen, with the new drivers?
Twl...The speaker drivers I listened to were at least 3-4 yrs old. They were both in homemade cabinets. I don't think there are any dealers in my area (Southeastern Michigan) who carry anything with Lowther drivers, don't know how else I could get a listen to something new. I also still think that, at 100db efficient, the system might be too noisy for my liking. I'll check some Lowther websites, however, and see what's happening.
Another candidate may be the smallest Galante speaker ($2500-$2800) new. I have no experience with it myself, but it has received favorable reviews (both for its sound and low wattage capability).
I think that it is a coaxial design (tweeter mounted in the center of the LF driver) which usually works quite well in close spaces.
Don't know if this interests you, but I plan on building a pair of single driver speakers (for the 2A3 amps) using vintage Stephens Trusonic 8" drivers. I was considering new Lowther drivers, but (as you mentioned) I do not feel that my Bottlehead gear is quiet enough to make a good match.
The Abbey speakers (mentioned above) are single driver speakers (using Fostex) that are based on the Voigt pipe design (same as TWL's speakers), but they are well below 100 dB efficiency. The last time I checked the Cain & Abbey website they were offering a "near field" version of the speaker that might be suitable for your room (depending on the layout).
Dekay - What is the website address for Cain & Abbey. Tried Google search and didn't finf anything.
Here is the address:
Keep in mind that I have never listened to the line, though there should be some user feedback shortly @ Audioasylum.com (someone just received a pair). Can't remember which forum, but you can now run a full site search @ AA (hit search and it is in the drop down menu).
I cannot imagine getting bass out of this design, but TWL has and perhaps this model does so as well. I'm not a bass fanatic, but do require a reasonable amplitude on the low open "E" string of a Jazz bass. Many speakers rated @ but 55 Hz perform this task within their useable roll off (even though the note is centered @ around 42 Hz), so specs are not everything when it comes to listening enjoyment.
Here is another website that may be of interest to you (also the "brother" single driver website which has a link @ the top of the page).