Calling all SET fans


What is the least expensive, aka cheapest speaker available
that will do a decent job on classical chamber music on 3-8
watts ?
schubert
For what it's worth, I did a 4-part series of articles on my audio blog about speakers for SET amps. The first article is right here.
I purchased a pair of Omega Super Alnico monitors, with the 6-inch hemp cone driver with alnico magnet motor. I'm still tweaking my system and breaking them in, but at some point I'll likely post a review.
Ironically, I was looking at those Mapleshades and almost jumped. Then I found the Isoacoustics that appeared to address the same issues for 1/3 the cost and with many rave reviews on Amazon. Much different aesthetics though. isoacoustics are designed for pro use. Will be interested to hear about the Mapleshades.
I just got a great deal on a pr of Mapleshade Bedrock floor stands, coming next week, see how they do .
I have Isoacoustics stands under my Triangle Titus. The difference was huge, night and day in detail, soundstage, imaging, bass articulation. Herbie dots are a similar product to help isolate speakers from floor and room acoustics I believe so similar results not surprising. One would never know what the Triangles are capable of in my house without addressing the acoustic isolation issues.
Map, I just put small Herbies fat dots under the 202's at each corner. Big jump in instrumental separation and placement, at 5 bucks a piece I know of no better tweek.
I could go on and on how great they sound but nobody would believe me .
The 6bm8 sounds tad better than the EL84 which sounds better
the EL34. The little EE is excellent .
AL just a gut estimation but I suspect the 90 db estimate to be reasonable based on the relative volume I achieve off the Titus compared to the other speakers I run off the same amp, dynaudio monitors and the Ohm Walsh both of which are generally rated a few db less efficient. The Titus are significantly more efficient and go louder much faster. The tradeoff for their size is the last octave of bass or so which helps make them a good match to a flea powered amp despite their small size. As mentioned they also employ a very simple crossover I seem to recall. Also as Schubert mentioned they use a lightweight paper cone bass driver and are very fast and detailed. They were the speakers that succeeded in weaning me off Magneplanar a number of years back.
A-gon should install a special button to click on for all
who profit from Al's advice to donate a few bucks to his account for every answer .
Way to go, Mapman!

A speaker that is a **true** 90 db/1W/1m/8 ohms driven by 8 watts should be able to generate SPL's in the mid-90's at a centered listening position about 10 feet from the speakers. Which would certainly seem likely to be adequate for the majority of chamber recordings. The problem that often seems to occur, though, as Duke mentioned early in the thread, is that the specs are inaccurate and/or misleading.

One commonly seen example of a spec being misleading even if it is accurate would be a spec such as 90 db/2.83volts/1m for a 4 ohm speaker, or for a speaker that is spec'd as having a higher impedance but which is more accurately characterized as a 4 ohm speaker. The 90 db in that situation corresponds to just 87 db/1W/1m, since 2.83 volts into 4 ohms is 2 watts rather than 1.

In this case, though, it would seem that the 90 db figure is an honest one.

Best regards,

-- Al
My Triangle Titus have been the bomb for several months now in my wife's 12X12 cathedral ceiling sunroom, running off the 500 w/ch Bal canto ref1000m Class D amps in the basement below (via in-wall speaker wires I had run when the house was built).

So when I throw a flea powered tube amp at them some day, the other end of the amp spectrum essentially, it will be very interesting. They are the only speakers I own that might sound even better perhaps with just a few pure watts of tube amp power, but they are hard to fault as running currently even.
Thanks, Map -beyond all doubt Triangle is tube time, I suspect they are around 91db in the space I have .
I'm listening to Baroque Organ right now (Couperin )and they are doing fine , real fine, Guitar is off the charts as is piano !
+ EE makes very high quality stuff .
Now, I will wait to hear results with Triangles and SET or SEP, if you are still inclined to take things even further in that direction. The EE amp seems pretty sweet already. Its one I have considered as well from time to time.
Schubert, you made my day.

Glad to hear it seems to be working well. This may well accelerate my plunge towards a flea powered tube amp to use my Triangle Titus XS sooner rather than later.

Just goes to show to always take specs with a grain of salt. I see no reason why most any amp including SET would not do well with the Triangles. They are hard to beat in their price range as you describe and they have a reputation from users for sounding best with tube amps to start.
As usual the genius of the one and only Mapman strikes again .
I'm listening right now to my Triangle Titus 202's, the cheapest speaker (600$) ever to be a Stereophile Class B , with my 8 watt EE Minimax integrated . They are fast as lighting and coherent as hell with a cap crossover at 6 K.
VERY realistic tone and staging , one of those hard to shut off jobs . At a rated 90db eff I never thought to use then with the little Minimax with Hitachi 6BM8's , but the presentation is flawless !

Smokes everything else I have on hand in my small condo,
Meadowlark Kestrel 2 and Eagle
Silverline Prelude
Totem Model 1 Sigs
Gallo CL-3
Rega R1

Wire is Morrow MA-5 and SP-4 biwire .
I have less than a grand into the speakers and amp and about $500 in wire .Wish I knew this 20 years ago, but I was too busy listening to music ,
If building around a particular SET amp, its only gonna pay to hear speakers with the chosen amp more so than ever. What speakers sound like with other amps will not mean much.

Schu already has the Triangle Titus speakers to try with his current EE amp and then maybe with teh new SET that I think have a chance to work well. I would wait to hear that first before making any other moves regarding speakers.
Schubert,
Why not listen to DeVore 0/96 or 0/93? Maybe Rethm? Coincident Triumpth? Each several times, perhaps six or seven times your budget, but hey, maybe "you can s-t-r-e-t-c-h a bit". Rob
Schubert if you are going to listen to some Omega Speakers, try to make sure that they are using the RS5 driver. Compared to the older hemp, it's much warmer, has lower bass and just sounds better. The difference is not small.
Shu, I heard the Glow audio Single Ended Pentode design amp at a show a couple years back and thought the sound to be one of the best of show. Very nice product that will not break the bank!! I think think it was running with Audio Note speakers of some sort, or something similar, but not sure.

Some of the Decware amps have also caught my eye for just a bit more.

I think the speakers to be used and kinds of music to be played and how loud more than ever are perhaps the biggest considerations in determining what simple topology tube amp to choose. You can spend as much as one chooses on either amp or speakers depending. The work involved to deliver music realistically never changes, but there are many ways to skin that cat.
My understanding is use of one output tube versus multiple tubes that must be "integrated" well as discussed above is the inherent advantage of a SET.

The downside is the power limitation and the distortion that comes into play if the amp is pushed hard at all.

So its a very clean pure and simple circuit design that is the benefit but the "slack" must be picked up elsewhere, by the speakers which correspondingly have to be very efficient and a very easy load otherwise you cross into high distortion territory a lot faster than with other more "scaled up" designs.
Thanks, Jet. Yes, implementation of the phase splitter in a push-pull amp is certainly a critical aspect of the design. I can't offer any particular insight, though, regarding the tradeoffs between use of a transformer and use of a tube for that purpose.

I'd imagine, though, that as with many things in audio either approach can provide results that are either better or worse or similar to the other, depending on the specific implementation and the other aspects of the design.

Best regards,
-- Al
I was just reading about the cool EE amp. It uses one of the triode sections for the input gain stage which then goes to the other triode section of the other tube to split the phase of the signal. The signal is then recombined in typical push pull fashion in the pentode sections of each tube. At least that's how I think I am reading it.

This phase splitting is the most crucial part of a push pull amp and if not done perfectly can diminish the sound quality of a push pull amp. i think in one of Shindos amps they split phase with an interstage tranny. Al might be able to better comment on the strengths and weaknesses of plitting phase with a tranny vs tube. Jet
Al, you know the EE uses 4 6BM8, 2 a side ?
Thanks for the lesson , I really appreciate it .
The 6BM8 combines a triode section and a pentode section in a single tube. The triode section is much more limited in power capability than the pentode section, so the triode section is normally used to drive the pentode section, which in turn provides the amp's output power. But the pentode section is itself very limited in power capability, such that to achieve 8 watts I believe the EE integrated must be using two of them in push-pull.

So as might be expected there are many variables that distinguish the EE integrated from a 300B or other comparably powered SET. One being single-ended operation of the power tube vs. what is probably push-pull operation in the EE. Single-ended operation avoids "crossover distortion," which affects the zero-crossing of the signal and therefore becomes increasingly significant at low power levels. Another being use of a triode power stage in a 300B amp vs. a pentode power stage in the EE, with good triodes generally being considered to be more linear (at least when not pushed in terms of power delivery). Another being that the 300B, as well as the lower powered 2A3 and 45 tubes, being especially well regarded for their sonics in comparison to most other triodes. Another being that since the 300B, 2A3, and 45 tubes are relatively expensive, they tend to be used in amp designs that are less constrained by cost considerations than amps that would be designed around less expensive tubes.

So as might be expected many factors are involved, undoubtedly including others that I haven't thought of.

Best regards,
-- Al
Al, then what makes a SET amp sound better that my neat 8 watt Eastern Electric 6BM8 integrated ?
Len, no, I was not implying that. My mention of the fact that the Almarro amp and the Dynamo are not SET (Single Ended Triode) amplifiers was to make the point that for them to perform at their sonic best, whatever that best may be, it **might** be LESS necessary to run them at a small fraction of their rated power than in the case of a true SET.

Best regards,
-- Al
Al, if I'm reading you right it would seem one should go right to a 3-4 K 300B amp or just forget about it ?

best,
Len
The main improvement of the Dynamo MK II is bigger and better transformers. Israel Blume(Coincident owner/founder) believes transformer quality is a "crucial" factor for tube amplifiers. He feels this MK II is a notable upgrade. Based on my dealings with him, I wouldn't doubt this at all.
I suspect this is a very stout and robust 8 watt amplifier with appropriate speaker matching.
Schubert,
I owned the Almarro 205, in fact sold it here on Audiogon. Nice little amp, but watts aside the Coincident blows it out of the water in every meaningful parameter. How come on Audiogon a poster says he/she wants to spend no more than a thousand bucks and folks start recommending multiple thousand dollar speakers? This happens over and over, pet peeve of mine. Best, Rob
11-17-15: Swampwalker
YW, Schubert. Two watts normally would make no discernible difference but that's a 33% increase, so maybe so. IIRC, Atmasphere has pointed out that very important to get adequate power w an SET amp because because their distortion rises very rapidly as power output goes up. I have no independent knowledge of these kind of technical issues, so if I'm not remembering correctly, my apologies.
You're remembering correctly, Michael. Atmasphere has said in a number of past threads that to get the best sonic performance from a SET amplifier it should not be asked to supply more than a small fraction of its rated power (something like 25% if **I** am remembering correctly), because of the progressively increasing amounts of distortion SETs produce at increasing power levels (and the progressively smaller amounts of distortion they produce at decreasing power levels).

However, neither the Almarro A205A nor the Coincident Dynamo is a SET, as the EL34 and EL84 are not triodes. And based on their power ratings and on the schematic and comments shown in this review of the Almarro A205A MkII I'm pretty certain that neither amp is even operating those tubes in the so-called triode mode. Therefore I'm not certain of the degree to which Ralph's point might be applicable to those particular amplifiers.

Regarding the difference in power capability, the Almarro A205A MkII is rated by the manufacturer at 5 watts, with the review indicating 4.8 watts. The difference between 4.8W and the 8W rating of the Dynamo is 2.2 db, not a great deal but perhaps enough to be significant on some recordings. As we all know, though, specs commonly don't tell the whole story when it comes to subjectively perceived power capability, with distortion characteristics, power supply robustness, and other factors being involved.

The one other comment I would offer at this point is that the multiple mentions on the second page of the Almarro review of hum, buzz, and the need for a cheater plug would definitely give me pause. I say that in part because in the photos of the unit there and elsewhere, and also based on the schematic shown in the review, it appears to me that the ground shells of the RCA input jacks, and hence the circuit ground of the unit, are probably connected directly to the chassis (although I can't tell with total certainty). Which would inherently create a susceptibility to ground loop issues, that may or may not materialize depending on the grounding configuration and other characteristics of the component(s) it is connected to.

Best regards,
-- Al
Thanks , Fan . As I remember when brand new Mullard EL 34 were 20 bucks a quad it would would be impossible for me to spend 600 bucks for a pair for if my net worth was 20 million .
As I recall when I bought the new quad of Mullard EL84 I have 20 years ago they were 30 bucks .
Len,

A few thoughts based on some of the recent posts. First, with respect to the Ref 3A deCapos, I found them to be a bit slow in the low frequencies when driven by the dynamo. I think they need more that 8WPC. Second, it might be worth waiting to see what gives with the Dynamo MK II that Mikirob mentioned. If it is a substantial improvement, it might be worth the wait, if only for the used MK 1's To hit the market. I'm using the Psvane Philips reissues, which are pretty good tubes but with some reliability issues. I bought a quad, and got two usable tubes (which is all I needed) plus a refund on the two duds. I'd try to snatch a pair of nos mullards before they are all gone.
The extra 2 watts may or may not make a difference, depending on which speaker you choose.
YW, Schubert. Two watts normally would make no discernible difference but that's a 33% increase, so maybe so. IIRC, Atmasphere has pointed out that very important to get adequate power w an SET amp because because their distortion rises very rapidly as power output goes up. I have no independent knowledge of these kind of technical issues, so if I'm not remembering correctly, my apologies.
Thanks Swamp, I have access to some Omega 3xr with the hemp drivers ,I 'll try those before I buy any other speakers .
Gang, my question now just boils down to the amp.
The Dynamo looks like a winner and I have NOS Mullard 5U4G and 5ARF on hand but the EL 34's have on hand are pull-outs from old Dynaco 70"s and the Russian "reissues" may be great and all by MY ears just don't believe it.
I have heard the Almarro A205 quite a bit and was very impressed , plus I know from many back in the day trials my ears much prefer EL84's to EL34's , and I have NOS prima EL84's on hand but will the extra 2 watts of the Dynamo make a diff ?
I've never heard the Tektons but for chamber music, which implies less dynamic range than full orchestral pieces, I think the Ref 3a monitors deserve a serious look. With no real "crossover", they put most of the wattage to work. I would also look at Coincident monitors.
Schubert,
I listen mostly to Jazz, Classical of any type, Folk, Rock, Pop, hey, I'm a music lover, the Tekton plays them all extremely well. What do you expect to get for $1,000? And how expensive is real bass? The low-E on an electric bass is about 40hz, the tekton I'm talking about Lore, 30hz, 98db, 8 Ohm nominal, or Lore M, 38 hz. Reference 37hz, where else you getting that for these dollars? You get 95% or more of the costly stuff. The rest, treble, mids very good. My bias is I am a "timbral" listener. Tone, texture, timbral rightness; with the right ancillary equipment these are fabulous performers. Best, Rob
Brownsfan, Charles, Schubert,
Coincident is coming out soon with the Dynamo Mark II. Larger/better trannies, plus Blume is switching to 5AR4 rectifier...I really don't get some of the comments about Tekton. Every reviewer that has reviewed them gives them extremely enthusiastic high praise. I bought mine prior to any review, and must concur. Tim Smith, 6moons likes them better overall than his Harbeth 7. Most other reviewers have compared the Tekton to speakers that cost three or four times more. Usually like Tekton more, or tie. How can you go wrong at $799 for the Lore Reference for low power at 96db, 8 Ohm nominal, bass to 37hz for less than $1,000? They kill the Zu Omen (much more expensive). The Stereo times Reviewer favorably compared the Lore Reference to DeVore 0/96, a small amount of hyperbole? Yes, but only by a couple of smidgen. Their are other reviews that make similar statement. All I know is that top to bottom I really enjoy them. I listen to my brother's Harbeth HL5 ($6,500) frequently and between them, to me, it's in the ear of the beholder. I know the Tekton Lore/M-lore are better in my room with head-to-head competition to the DeCapo with either my Coincident Dynamo or Cary V12/SLP98 combo. If I lived near Brownsfan it would be interesting to compare side by side to Coincident Triumpth. I suspect the Triumpth would Triumpth, but by how much? For $650-$1,000 I do not think you can do better. Best, Rob
In that one cannot have all three of bass, efficiency and small size in a speaker its a useful exercise to rate a hifi speaker in each of these categories.

Being conservative on a scale of 1-10 for my Triangle Titus XS:

bass - 6
efficiency - 7
small size - 9

I also have Realistic Minimus 7s that I think could work well within their limits off a SET amp

bass - 4
efficiency - 5
small size - 10

Dynaudio Contour 1.3 mkII

bass - 7
efficiency - 4
small size - 8

OHM 100 Series 3

bass - 8
efficiency - 6
small size - 6

Adding good powered sub set up well to the mix eliminates the limitations in most all cases.
Also with a good quality powered sub or two set up just right, almost anything is possible otherwise. So there is always that very practical option available to help pick up the slack whenever needed.
Having said all that, being one who is always ont eh lookout for something a little different, I greatly look forward to testing the SET amp waters myself someday soon starting with modest expectations 9and my triangle Titus speakers if I still have them)and seeing where things might go from there.
A few watts shows its limitations most with lower frequencies. Either the speakers have to make up for the lack of muscle needed to produce quality bass by being very large and if also good quality very expensive, or else you have to punt on the bass to some extent with the speakers depending on your needs. You can have 2 or three bass, efficiency, or small size but not all three.

I heard large more expensive and "efficient" Zus off a set amp at a show a few years back. Sounded very good for smaller scale classical works but not for works requiring more power and muscle in the delivery. The Zu guy admitted the SET was underpowered for all kinds of music. He chose his demos carefully to play well within the limitations until I asked for something more challenging.

I think my little Titus speakers could have done equally well as the Zus (Essence I believe) with the music demoed. If they had used a more suitable powered amp then I think the results may have justified the cost of those Zus. The demo was clearly put together to convince people the Zus were suitable for use with a SET amp but they were definitely quite limited depending with the SET.

So I take all adverts regarding teh capabilities of "high efficeincy" speakers off a few watts of power with grains of salt. Maybe in some cases.

The only demo I have ever heard where a flea powered set performed top notch with all kinds of music involved very high efficiency, large and expensive custom Goto horns. I suspect other very high efficiency horns like Avantegarde can do the job as well. But I doubt any speakers are efficient enough to truly perform top tier off a few watts in lieu of being highly horn loaded to gain the efficiency needed. Even then large bass units are required to fill in the low end.

So I think one just has to be realistic about the limitations. For smaller rooms, lower volumes, and music forms where lower octaves do not mean much, you are golden with smaller high quality moderate efficiency speakers in many cases, but the ante increases exponentially from there.


Smallest amp I used was a bottleneck , I had a bottleneck pre at the time . I think it was about 5 watts but no set of course.
But I've heard the 4 " Fostex many times in many systems, the upper mids are just plain rough ,at least the way my ears work. They can be overall OK, but the hemp drivers Omega uses
now are far better .
I've never hears a real SET rig, as least as far as I can remember .
I'm leaning to have Sean at ZU make me a used Omen for classical on that $999 "Dirty" deal they have on their website . Not least because the ZU Event wire I have is VERY good . And I enjoy the placement fuss the Omens seem to require .
I used various amps I had at the time ,smallest was a low powered bottleneck I borrowed to use with my

bottleneck pre, I think it was about 5 watts but no set of course.
But I've heard the 4 " Fostex many times in many systems, the upper mids are just plain rough ,at least the way my ears work. They can be overall OK, but the hemp drivers Omega uses
now are far better .
I've never hears a real SET rig, as least as far as I can remember .
Schubert - when you had your Omegas, were you using a low-powered SET amp to drive them? IMO, that's what the single-driver thing is really about. I remember a friend's system with Zu speakers - I was not very impressed when driven by the big 60-watt Cary monoblocks, but the magic happened when we hooked up the 2-watt Yamamoto. Really not enough power for the Zu's, but you could definitely hear the beauty come through.
Never heard these speakers but the Birch Acoustics Sparrow on AudiogoN MIGHT fit the bill ... 4" full range driver in a a laminated birch cabinet. Very attractive build (IMHO) and a nice price ($380). Claimed 87db efficiency but no crossover so should be an easy drive. Hopefully someone who has heard them will chime in!
Schubert,
If your friend had issues with the Tekton I can understand your hesitance reservations. Mikirob, Brownsfan and I have very similar taste, so when one of them is enthusiastic about a product it gets my attention. There's a very long thread comparing Zu Omen and Tekton in the audiogon archives.
Best of sucess to you in your search.
Charles,