Guys, by the way, many thanks for all of your replies, landrupp started this thread and now it comes to life again and 1669 has so generously shared his information and photos!
Ever since I got those cabinets I am posessed by the idea of trying the Axiom in them and all of this gives me courage to keep thinking about a solution.
After reading 1669's postings I think I will solve the magnet size problem by moving the driver forward via a second baffle.
In the meantime, I almost asked you (1669) how ON EARTH did you fix the new baffle without the screws being visible, but I think I figured it out: they are driven from behind, right? So you take the driver out and then you reach with your hand armed with a hex wrench (inbuss) to unscrew it. Clever!
Ever since I got those cabinets I am posessed by the idea of trying the Axiom in them and all of this gives me courage to keep thinking about a solution.
After reading 1669's postings I think I will solve the magnet size problem by moving the driver forward via a second baffle.
In the meantime, I almost asked you (1669) how ON EARTH did you fix the new baffle without the screws being visible, but I think I figured it out: they are driven from behind, right? So you take the driver out and then you reach with your hand armed with a hex wrench (inbuss) to unscrew it. Clever!
unfortunately, as far as I'm concerned, I think my axiom cabinets will see the light in many months, for the moment I don't have the right desire to start everything ... how to say, for now I'm content to put the hay in the barn.
however dear rokikiki i hope you can go ahead before me i will always be glad to appreciate your progress
No as I am all revved up let me tell you my secret. Vintage Sony got a big spot in my heart. I love the sound and built quality of these from the mid sixties up to beginning of the seventies. The top dg is the TA-1120, the very first one with no headphone out on the front. Another is the big receiver STR-6120 that I got from USA. there was no wooden sleeves so my carpenter friend helped me with a bunch i Walnut after one original piece.
Attachments
Wow, they are both wonderful... There is something great about those old receivers (Luxman, Sansui, Sony, Pioneer and the rest). My old Tannoy loudspeakers went to the secondary (studio) system once the Coral horns arrived and I wouldn't mind driving them with one of these wonders! Bleeding-ears-testing-grade equipment and one-ton kilowatt monoblocks are nice in the Munich Audio show, not necesarily if you need to actualy live a life near these sound sources. 
By the way, as I mentioned before, my enlarged Corals have old RFT german drivers and they are very listenable. No harshness. My friend had the (similar) Jeriho horn with Fostex and his wife buldozered him into selling them under threat of divorce.
By the way, as I mentioned before, my enlarged Corals have old RFT german drivers and they are very listenable. No harshness. My friend had the (similar) Jeriho horn with Fostex and his wife buldozered him into selling them under threat of divorce.Oh for the love of bejeesus, here we go, now I am interested in this project. Need to sleep but still clicking
Rokikiki, if your HiFi-system demand a lot of watts something is wrong. Less than 20W can do and if the speakers need much over that you have to start all over again. Around 100dB in speaker sensitivity is to go back to the old golden days and nothing could beat that today. There is a false security to believe in power full amps when the very best of sound quality is to be found in the sixties and beginning of the seventies IMHO.
No, no, of course, no big watts, you are perfectly right! My Coral horns are happy with something like 2x4 watt! I am curious to listen to 2a3 tubes, haven't done it yet. The thing is that my music preferences are a little bit all over the place. I listen to baroque, jazz, electronica, dubstep, rap, blues, r&b, the likes of Bela Fleck (when my wife is not around), but also sometimes Queen, 10cc and so on. So I need something that is not very specialized.
An AudioNote OPPO sounded very nice in my system when I borrowed it. The afore mentioned Audio Innovations was clearly too strong at 12 wpc. It was almost impossible to adjust the volume. Musicality was good but larger orchestras were slightly falling apart into noise. My best experience was with a 300B. The sound track from the Frida movie, from Latcho Drom were just stunningly beatiful. But that is no surprize with a 300b. As I mentioned, these speakers are going to force me into some serious amp upgrade (and force my finances as well, this is an area where you get what you pay for).
What you have seems to be fantastic (the Audion).
An AudioNote OPPO sounded very nice in my system when I borrowed it. The afore mentioned Audio Innovations was clearly too strong at 12 wpc. It was almost impossible to adjust the volume. Musicality was good but larger orchestras were slightly falling apart into noise. My best experience was with a 300B. The sound track from the Frida movie, from Latcho Drom were just stunningly beatiful. But that is no surprize with a 300b. As I mentioned, these speakers are going to force me into some serious amp upgrade (and force my finances as well, this is an area where you get what you pay for).
What you have seems to be fantastic (the Audion).
I was going to ask the same thing. Thank you for your answer 1669.
As I mentioned, 300B was wonderful with my horns. I am also curious about 2a3 but am a bit aprehensive of it, because I assume it might be more specialized (vocal and instrumental jazz, chamber music and the like) and I also assume it might be bass-shy. I often find that when bass is described as "precise" or "well controlled" it is just an euphemism for "mostly absent" or "less audible". The power seems to be right on. 2a3 being mostly 2*3.7W compared and 300B being mostly 2*9W.
Perhaps someone could comment on their experience with 2a3 and high efficiency horns with a more wide repertoire of music?
As I mentioned, 300B was wonderful with my horns. I am also curious about 2a3 but am a bit aprehensive of it, because I assume it might be more specialized (vocal and instrumental jazz, chamber music and the like) and I also assume it might be bass-shy. I often find that when bass is described as "precise" or "well controlled" it is just an euphemism for "mostly absent" or "less audible". The power seems to be right on. 2a3 being mostly 2*3.7W compared and 300B being mostly 2*9W.
Perhaps someone could comment on their experience with 2a3 and high efficiency horns with a more wide repertoire of music?
If your 2a3 amp is "bass shy" you've messed up on your iron. Or your speaker sensitivity.
Joe Roberts once commented that he'd never met a 2a3 amp he didn't like.
My observation from watching others since the early 90s is that 45 > 2a3 > 300b when it comes to linearity (this unfortunately only applies to NOS stuff, not all the current stuff) but you get less watts.
(Duty of disclosure: I have half a dozen 2A3s and associate PP iron which have been staring, accusingly, at me for at least a decade. One day....)
Joe Roberts once commented that he'd never met a 2a3 amp he didn't like.
My observation from watching others since the early 90s is that 45 > 2a3 > 300b when it comes to linearity (this unfortunately only applies to NOS stuff, not all the current stuff) but you get less watts.
(Duty of disclosure: I have half a dozen 2A3s and associate PP iron which have been staring, accusingly, at me for at least a decade. One day....)
Thank you so much for your insight Thoglette!
Can you also comment on the musical genre question? I have found that many users of a [SET amp + high dB loudspeakers] have a predilection to chamber music / jazz and the like. It might also mean that they continue upgrading their system while listening more and more to the same music - which potentially makes it actually worse for different source "material". Do you think 2a3 could deepen this phenomenon? In other words, is it more flexible or less flexible than 300b?
Am curious on what amplifier pairing would be most beneficial to the Axiom 201 single driver system we are talking about (I have heard specialized systems, that only play Nina Simone, Leo Kottke, Diana Krall and Andrea Segovia, falling apart with some other types of music).
Of course i ask this question with the full understanding that there is nothing like an universal reproduction system.
A horn like the one we are discussing is already a choice that narrows possibilities, wonderful as it may be. I only want to make sure the amp choice will not further narrow this predilection.
Note: as I multiply my questions, and gratefully read your answers, I am dragging my feet with the actual build. An unplanned pandemic-related quarantine has isolated me for a while. For now I am trying to source some tools. My main challenge is fitting the magnet and I am planning to do this by using a second, superimposed baffle, while trying to change the internal volume of the enclosure as little as possible. I will definitely post results here.
Can you also comment on the musical genre question? I have found that many users of a [SET amp + high dB loudspeakers] have a predilection to chamber music / jazz and the like. It might also mean that they continue upgrading their system while listening more and more to the same music - which potentially makes it actually worse for different source "material". Do you think 2a3 could deepen this phenomenon? In other words, is it more flexible or less flexible than 300b?
Am curious on what amplifier pairing would be most beneficial to the Axiom 201 single driver system we are talking about (I have heard specialized systems, that only play Nina Simone, Leo Kottke, Diana Krall and Andrea Segovia, falling apart with some other types of music).
Of course i ask this question with the full understanding that there is nothing like an universal reproduction system.
A horn like the one we are discussing is already a choice that narrows possibilities, wonderful as it may be. I only want to make sure the amp choice will not further narrow this predilection.
Note: as I multiply my questions, and gratefully read your answers, I am dragging my feet with the actual build. An unplanned pandemic-related quarantine has isolated me for a while. For now I am trying to source some tools. My main challenge is fitting the magnet and I am planning to do this by using a second, superimposed baffle, while trying to change the internal volume of the enclosure as little as possible. I will definitely post results here.
Goodmans Fullrange with 2A3 PP
Hi Rokikiki
At my 2a3 / 6b4g pp amps there are in one room Triaxiom 212 and in the other room oval Goodmans Alnico 6 1/2 to 9 1/2 '' attached and I am very comfortable in listening to soloists, bands and orchestras playing acoustic music, electric jazz-rock, Italian pop music among many other styles. I can imagine that music like techno, heavy metal a.o. would sound better on a different equipment. As an upgrade I would exchange the amps with 2a3 / 6b4g SETs because the volume pot is usually between 8 and 9 o'clock and the hum could be an issue with high efficiency speakers.
Eric
Hi Rokikiki
At my 2a3 / 6b4g pp amps there are in one room Triaxiom 212 and in the other room oval Goodmans Alnico 6 1/2 to 9 1/2 '' attached and I am very comfortable in listening to soloists, bands and orchestras playing acoustic music, electric jazz-rock, Italian pop music among many other styles. I can imagine that music like techno, heavy metal a.o. would sound better on a different equipment. As an upgrade I would exchange the amps with 2a3 / 6b4g SETs because the volume pot is usually between 8 and 9 o'clock and the hum could be an issue with high efficiency speakers.
Eric
There's a few things going on here.
On one hand we have the complexity; spectral density; and actual air displacement required by the music (at normal levels).
On the other: how the amplifier misbehaves when pushed.
At one extreme, a solo (jazz) instrument or voice has most of the power in the mid range; It has dynamic range but doesn't need to move much air and is short on complexity.
In one corner "doof" dance music moves a lot of air but the volume is basically fixed and there's little complexity. Depeche Mode "Personal Jesus" or similar (The opposite of modern chamber works or contemporary - say Aust. Art Orc. "ringing the bell backwards")
In the final case, we have a symphony orchestra playing a piece involving and organ and a massed choir (Saint-Saëns Sym. #3 comes to mind)
MASSIVE OVERSIMPLIFICATION FOLLOWS
Now, an SET amp clips nicely if you do it occasionally and the onset of 2nd is pleasant on single notes. However, that 2nd harmonic will make "Ringing" unpleasant. You simply won't be able to drive the bass you need for "Personal Jesus" to any sort of level (unless you have 833Bs). And Saint Saens will be mush.
I had a 3/4 watt SET amp for a while and it was (is) delightful, within it's constraints.
At the other extreme, a standard hi-power op-amp (most commercial amplifiers) will sound bad on anything that doesn't want to RAWK once it gets into class AB (due to power rail sag induced IMD) and awful if it ever clips (too much loop gain) and likely to oscillate or blow up into difficult loads. It's also very likely to behave poorly at low power levels (poor SNR, not enough standing bias, noisy power supply etc, poor diff amp linearity).
These are the challenges for this architecture.
There are plenty of good amplifiers with this architecture (NAD 3020 being the cheapest and most iconic - I've not bought anything in this area for a few decades so perhaps others will have some ideas.)
So that SE Class A and Power-Op-Amp done.
What else is out there? PP Class A , Class B and Class D plus hybrids
Class D - I'm not competent to comment on, beyond noting that it took two decades to work out all the things that could go wrong with CD players.
Class B - Quad 405 (Walker) and one Mr Blomley played in this space but they never managed to get them to take off more broadly. There's also low-loop-gain PP Class AB - from AKSA to ME (Peter Stein). All of these have their adherents.
PP Class A with little global feedback. This has been the n'est plus ultra for over a century. It's hot and expensive per watt. Brooks, Krell, JLH, Sugden all have icons in this space. Probably the most modern valve expression is Lynn Olsen's Karna.
Going PP immediately removes the 2nd harmonic, which (if your 3rd is low enough) "solves" the IMD problem. It also makes output transformer design easier (valve or SS) but (re)introduces the zero crossing problem.
So, that's the major architectures.
At the Cheese vs Wine vs Bread level of MASSIVE OVERSIMPLIFICATION
Next twist: different amplifiers behave differently as speaker impedance varies. Generally a single driver amplifier will roll off as its impendance rises at either end of the frequency spectrum: so an amplifier with higher output impedence (behaving more like a current source than a voltage source) may compensate by driving more power (rather than lesss) into the speaker.
Depending on the speaker designer, of course.
Penultimate twist. It's the room /speaker interaction that's most critical. I can't really help here beyond noting that big rooms need more acoustic power. And apartments need less than country cottages.
I'm going to assume that you don't need too many watts, so a handful of PP class A watts is likely to be a viable option. The JLH 1969 is a relatively inexpensive way to get into that space. My bias is for DIY. Maybe Sugden or Musical Fidelity A1 (by Tim de Paravincini). The Brooks PP tube amps are unfortuately "collectable" but one might be able to find a clone. Or call Gary Pimm for your Karna (almost as expensive and with good reason)
You'd be mad not to have something conventional for comparison - again the NAD 3020 is icon of cheap goodness for a reason. A lowish gain Op-amp (say a triode strapped ST-70) would also be on my sample list.
Final twist: each of us is sensitive to (offended by) different forms of misbehaviour. You need to know what gets your goat, for (each of) your musical genre(s).
Unfortunately that means we have to play swap-and-listen (over long periods), knowing that it'll not be proper A/B (unless you have an accommodating housemate)
Well, that's my (very long winded) opinion. With my very, very, very broad brush.
(For every statement someone will be able to find several exceptions)I hope that's of some use: perhaps some others will be able to suggest more (reasonably priced) options in each area.
Must run.