Believe it or not, these speakers do well with some power. Or, at least, a lower power amp with some bottom end. Well, maybe it's not surprising, given the amount of woofer cone they have. The wrong amp will really show poorly, far worse than with a lot of loudspeakers, and the end result will be thin and harsh.
That being case, I don't recommend 300B amplifiers, not enough grunt. Try something else, and you'll likely wonder at how much music you were missing.
My Atma Sphere M60 and a friend's Transcendents were a terribly poor match. I haven't worked it all out, but OTLs work great with front loaded horns, but seemingly not at all with back loaded horns.
I get very nice results with my Dynaco ST70 and an el cheapo Chinese 6AS7G push-pull integrated. So far, the best I've heard has been the Deja Vu push-pull 2A3. That amp kept me and my non-audiophile headbanging buddy happy spinning things like Led Zeppelin or Kraftwerk at crazy volumes. Most surprising to me, my Jadis DA60 mates exceptionally well with them. |
Charles1dad, I would say if Dpe's results were truly excellent, this thread would not exist.
Holding the variables you mentioned constant, the 2A3 tube will most definitely eclipse the 300B in terms of low end response and impact.
Taking the Lowther route, Isochronism's Beauhorn Virtuosos would be a better match for a 300B amplifier than the Hornings. Not to say that a 300B amplifier won't drive the Hornings, it most certainly will. But neither are you going to get to hear all of the speaker you paid for.
Dpe, yes, I did hear the Deja Vu push-pull 2A3 amplifier with Horning loudspeakers. I recently had that combination in my second system for a couple of months. Though I told my buddy (a fellow Audiogoner) who lent it to me to never sell it, I'd say if you are interested, he'd be willing to talk. It was the best amp I've thus far mated to my Hornings. Not sure where you are located, but if you're within driving distance of Philadelphia, most likely we can put the combination back together for you to come and give a listen to.
When I say crazy volumes, I mean 110 - 120 dB with both ease and requisite slam. My only complaint, you pay for some of that bass the solid state rectification yields by sacrificing a bit of tube rectification sweetness and romance.
Being a push-pull amp, as opposed to SET, its output was closer to 15 watts than 5. The much underrated 2A3 used in this configuration will sound a lot more like the typical 30 - 35 watt per channel tube amp, and the seat of the pants feel of the Deja Vu with the three loudspeakers I used it with was actually more than my Dynaco ST70, with some seriously meaty low end. 2A3 (2 - 5 wpc) SET amps will never come anywhere close in terms of power or extension. |
Charles1dad and Johnk, what you both have said is 100% true.
However, for whatever reason, you're missing my point that head to head - again keeping all other variables constant, the 2A3 will outshine the 300B tube when it comes to bass response. And, it will not be close enough to call it a race. |
Ralph, I think it comes down to what I relayed Bud being adamant about - a backloaded horn (BLH) and true TL are the converse of one another.
I believe your seminal work was done with a pair of Frieds, yes? The Frieds couple magically with the Atma Spheres. Even the current four ohm versions. In fact, the low impedance does not at all present the expected difficulty you see in more typical loudspeaker offerings. Bud was never surprised at this, and chalked it up to his raison d'etre - the resistive, not reactive loudspeaker via true TL, low Qts drivers, and (most importantly) series crossovers.
Unfortunately, as you know, he passed away (wow, has it really been almost a decade?!?) before I could really get it all out of him, and though he did provide a thorough and well thought out and worded explanation at the time, I'm unable to recall enough to discuss it intelligently. In summary, more or less, the TL will taper down as one moves through the line, snuffing out the backwave. The BLH will do the opposite, expand, and amplifying it. The ramifications of this are not subtle.
Fast forward a couple of years...a friend of mine who you know pretty well began using a well-known pair of single driver BLHs. One day we tried several tube amplifiers on them: an 16 wpc 211 SET, 15 wpc 300B PSE, 78 wpc Class A push-pull tube, and an 60(?) wpc OTL (not Atma Sphere).
For whatever reason, the first two amplifiers were head and shoulders better with these speakers than the latter. A real surprise, as other more ubiquitous speakers we had tried in the past always yielded the expected results. The two triode amps came across sounding powerful, particularly, the 211 SET. Most surprising, the 78 wpc PP tube amp, which one reviewer claimed sounded like 150 wpc, just could NOT put power into the speaker. Very strange, indeed. The OTL was thin, harsh, and lacking its typical low end performance. Perhaps, it could handle the driver itself, but the folded horn presented something far more difficult for it to push through.
Along these lines, I do believe there is something there in terms of the impedance these speakers present to an amplifier that is much different than the norm. It might not be something folks have yet been able to measure or quantify, but it's something that can be felt, heard, and experienced.
My own Hornings have been a challenge, the biggest I've had to work through in audio. Several times, I came close to giving up on them. The one thing that remained in my mind to the contrary was that Jeff Catalano has always done a masterful job in setting them up and producing what I consider perhaps the most natural and beguiling sound of any room at a show. It's taken me several years to get to the point where I now believe I can have these (or the next iteration) for the long term. Of course, no speaker (or product) is perfect. I do wish they imaged a whole lot better than they do. But the combination of clarity, dynamics, overall realism, and that aforementioned naturalness is something I do not hear in most loudspeakers I've been around. |
Charles1dad, this is a classic case of one of Bud Fried's absolute favorite topics, cognitive dissonance.
Simply put, you've proved unable to address the question I've put to you multiple times.
You may have compared (some 300B, some 2A3) different amplifiers. But as you initially maintained, there are so many other elements that go into such a beast, the picture becomes too murky to understand. Yet to simply accept that is to give up, without having obtained any actual knowledge or perspective.
Again, the answer is to return to one of the tenets of the Scientific Method, to observe the differences of two items being compared, holding ALL other variables constant. I admit it's a difficult task, and few have the ability, opportunity, or even desire to do so.
If we're going to be honest, which is the only route toward knowledge, you have no idea as which tube you prefer. The reason I say that is because it seems likely you have never directly compared the two tubes.
You have your own amps, which use one of the two tubes (in reality and objectively speaking, which of the two is meaningless) currently under discussion, and you like/love them. That's fair enough. As you said, "As long as we are both happy with our choices/results what else matters?" You "hope" that the tube your amplifiers employ sound better. If they did not, perhaps, it somehow invalidates your own purchase/judgement, and throws you out of equilibrium - the comfort zone. It's far easier to go round and round with someone like me here than to face such a possibility.
My experience is that high-end audio is all about compromises, making choices around such, and then going about living with them. In truth, my opinion is that for your application, the 300B is the far better choice. While I've maintained that the 2A3 produces the clearly superior low frequency response of the two tubes (not sure why that is so threatening a proposition), I, and I believe most people, couldn't live with just one of them. A 2A3 SET amplifier is simply not up to the task of driving all but a very few loudspeakers. |
Sebrof, "You either have an amp designed for a 300B or an amp designed for a 2A3. Therefore there will be variables. What am I missing?"
Buy or build an amplifier that can run both tubes. The only difference one needs to account for is the heater filament voltage; easy enough to get around with a power transformer with multiple taps. The rest of the amplifier remains the same, and then you can directly compare the two tubes. |
Charles1dad, "I disagree with that based on my own experiences."
Thus far, you've provided ZERO evidence that you were able to compare apples to apples when it comes to the 2A3 and 300B vacuum tubes.
Again, I will say, you need to hold ALL of the other variables constant before making your statement - transformers, power supply, circuit, driver tubes, etc. In other words, all of the things you previously laid out as making one amplifier superior to another. Then, and only then, will you be able to speak with any degree of authority.
This represents the essence of Scientific Method, developed out of the need to objectively draw conclusions when making comparisons between two things as we are doing with these two tubes. Otherwise, you're making a statement based on nothing beyond false hope.
Bud Fried liked to state that a backloaded horn was the opposite of a (true) transmission line. And, though of late it's become somewhat fashionable to try and equate the two, the differences come across as fairly obvious.
Though many times I've said that I've yet to find a better loudspeaker for the Atma Sphere than the TL. Conversely, I will again state that I have found that backloaded horns (Hornings and otherwise) do not mate at all well with OTL amplification (Atma Sphere or otherwise). As I've previously said, I haven't worked it all out, but there is something in regards to the impedance a backloaded horn presents to an amplifier that separates it from more ubiquitous loudspeakers, including front-loaded horns. What I am certain is Bud's point speaks to all of this.
That's not to say you can't drive this type of loudspeaker with such an amplifier. Obviously, you can. However, we all know that folks having poor (or worse) loudspeaker - amplifier marriages are as common as the day is long. |
