Single-Ended Triode (SET) Amplifier Revolution of the 1990s. Did it really happen? Was it Successful?

[G T Audio]

I cannot image anyone here would be in anything other than agreement with that sentiment ...However my point stands.

I have answered your point, but you must have missed it. It is not so much what I have done, but what others have not done. Having said that, there are some aspects of the design that are unique, which if you are not an amplifier designer, or if you have not had experience in circuit design you would not know about. Just looking at the parts used is no indication of the implementation, or the resultant audio performance, just as fitting a set of Michelin Pilot Sport Cup 2 tyres to your car isn't going to make it perform like a GT3.

 

[morricab]

I would hope AC would be quiet seeing as they make their own horn speakers. KR Audio only use a SET in their output stage. Their driver stage is solid-state so not a true SET amp as most would acknowledge.

While it is true that KR are hybrids they are still single ended from beginning to end. I have heard transistors used in this manner to very good effect. Until I heard AC, KR was probably my overall favorite single ended amp...they just sound really good. I am also fond of Ayon products (SET only models). I haven’t had the chance for a serious audition of Tron but will do so someday.

 

[Argonaut]

I have answered your point, but you must have missed it. It is not so much what I have done, but what others have not done. Having said that, there are some aspects of the design that are unique, which if you are not an amplifier designer, or if you have not had experience in circuit design you would not know about. Just looking at the parts used is no indication of the implementation, or the resultant audio performance, just as fitting a set of Michelin Pilot Sport Cup 2 tyres to your car isn't going to make it perform like a GT3.

Dear Me! Why are you reacting in such a peevish, tetchy manner , as tho I had made some sort of sniffy remarks about the quality of your amplifier design and build implementation?

I have not missed any point that you have made, quite the opposite , and have responded with plain facts and fair comment, yet you resort to questioning my grasp of electronics and amplifier design without the slightest idea of who you are addressing.... An auto defence mechanism has obviously kicked in!

You are the manufacturer of a particular SET amplifier who boldly claimed that you are the only designer who has implemented the use of SET amplification for use with a high sensitivity transducer that is fit for purpose, and by default disparaging a number of other very fine manufacturers and their products.

 

[Atmasphere]

I have answered your point, but you must have missed it. It is not so much what I have done, but what others have not done. Having said that, there are some aspects of the design that are unique, which if you are not an amplifier designer, or if you have not had experience in circuit design you would not know about. Just looking at the parts used is no indication of the implementation, or the resultant audio performance, just as fitting a set of Michelin Pilot Sport Cup 2 tyres to your car isn't going to make it perform like a GT3.

Yikes.

 

[Rensselaer]

Ok, thank you for the clarification.
I do not think Trios are more difficult to drive than Duos with modern SET like Crossfire.
I use also as a second amp Cirlcle Labs A100 integrated ( hybrid desing) and despite its 60 watts per channel I have the impression that Crossfire with 30 W pc is more powerful.
As far as sonics are concerned Trios do really need subs, without them the bass is limited to 100 Hz and the playback is limited to female voices ( outstanding btw).

After several month with REL Carbon Special and Trios I am more and more satisfied, but I wish they had a built in DSP like AG bass satelites.

Trios LE 26 are a significant leap forward compared to Duo Mezzo XD, the only thing is that Mezzos are easier to setup , especially the integration between mids and bass is easier.
Trios have better midrange, soundstage, micro and macro dynamics and in big classical create a more realistic reproduction of symphonic orchestra and the venue.

For smaller rooms Duos are probably the best value for money in AG line though.

But Trios with separate subs ( REL Carbon Special are very good , the only thing I am missing is DSP) are significantly better than Duos.
I had Duo Omega G2 , then Duo Mezzo XD ,now Trios and all of them are driven by Ayon Crossfire in its 3 iterations.

I would have thought the subwoofers would have difficulty matching the speed of the forward-pointed horns, resulting in odd phase or timing effect? Is such not the case?

 

[Cableman]

Ha

Integrity is a thing you have or don't have. There is no 'more' or 'less'. You have it or you don't.

FWIW you did not experience what they did with that equipment in their listening environment. There is no integrity in claiming that the equipment they experienced is 'drek' on that basis, regardless of your experience with that same equipment. Your experience is not theirs.

We examined the SET phenomena when it began in the early 1990s- was it a threat to our business model? We concluded that it was not (this conclusion has proven correct over the intervening 25 years or so). Many people prefer SETs over other types of equipment, including our own which we know for a fact outperforms all SETs made (measurable and audible). But that does not stop people from preferring SETs anyway, even when confronted by obviously superior (in every way) technology, some of whom might call that equipment 'drek'. Do you get my point?

hahahaha. You know ‘for a fact’ yours outperforms all SETs. I know ‘for a fact’ you’re wrong.

And no test bench ever made music. Measurements are a mere distraction used by disciples of such. What the heck they tell you about music reproduction is the sum total of zero

 

[marslo]

I would have thought the subwoofers would have difficulty matching the speed of the forward-pointed horns, resulting in odd phase or timing effect? Is such not the case?

Yes and no
Yes, because subs - be it REL or Avantgarde 231 XD subs are driven by independent built in - amps ( both REL and AG subs are driven by class D SS design ) and have drivers built from different materials than main speakers. So the way they transform the electric signal into acoustic wave ie speed and reverbations are different from horn drivers .
No - because deep bass is less directional and is perceived differently by the human ear/brain combo than mids and highs .
I am not prepared to go further with psychoaustic, the only thing I can say that tuning of bass sections ( be it with or without DSP ) is crucial , as well as phase and crossover settings.
Having said that, I am satisfied with 70-80 % of the recordings , more with vinyls and good hires files ,less with streaming and bad cds.

 

[Cableman]

Dear Me! Why are you reacting in such a peevish, tetchy manner , as tho I had made some sort of sniffy remarks about the quality of your amplifier design and build implementation?

I have not missed any point that you have made, quite the opposite , and have responded with plain facts and fair comment, yet you resort to questioning my grasp of electronics and amplifier design without the slightest idea of who you are addressing.... An auto defence mechanism has obviously kicked in!

You are the manufacturer of a particular SET amplifier who boldly claimed that you are the only designer who has implemented the use of SET amplification for use with a high sensitivity transducer that is fit for purpose, and by default disparaging a number of other very fine manufacturers and their products.

Clearly graham here has never been able to correctly set up an Audiopax Model 88 with its unique tuning device called Timbre Lock.(It’s the amp the first US distributor of Avantgarde used when promoting the Avantgarde line). If he could I doubt he would had conjectured the same bias toward his own SET.

Oh and for the record the Avantgarde -Audiopax combo is a marriage made in Heaven.

 

[Rensselaer]

Was there really a SET amplifier and horn speaker revolution in the 90s? Was anyone around in this hobby in the 1990s to witness it? Was it successful? What was the outcome and impact?

My impression of the recent history is that we have had some expensive hard to drive box speakers , like Wilson and Magico, that are thriving. (On the other hand, companies like Magnepan, and others that produced larger panel speakers, are on the ropes.)

To complement these hard to drive box speakers, the industry has had a solid state amplifier revolution with new brands like Soulution, Consoulation, CH Precision, etc., come around in the last 10-15 years. (Tube companies like audio research, on the other hand, seem to be on the ropes. and other tube brands are known only to experienced audiophiles and are not easy to find for those not in the know.)

Seems like these days audiophiles are older, deafer, and richer. They are after "hyper- details" and "accuracy", although most don't know what accuracy is and can't define it. And the hifi industry seems to be fighting for this segment.

An average person walking on the street will find a wilson, magico, sonus fiber, and McIntosh. But they will be hard-pressed to find a horn with SET.

Other than a few passionate SET - horn aficionados on this site, who have experienced the subtlety, delicacy, flow, aliveness, and emotional connection to the music these types of systems can deliver, what was the effect of this SET revolution?

I was living in Oregon in 1990 (and a bit before). I remember walking into a shop in Portland one day because I saw somebody soldering on a valve amplifier that looked like the McIntosh unit a friend had back in the early 1970’s.

Inside beautiful music was playing and it took me some time to actually locate where the non-descript speakers were. The man working there’ll told me that he had built the valve amplifier from scratch, the speakers too. He sold vintage hi-fi parts and pieces, valves, wire, and everything needed for DIY hi-fi.

After sharing stories about the best sound we ever heard, he said he belonged to the Oregon Triode Society and extended an invitation to me me to join their group. I did and started attending meetings at a dealers home in Lake Oswego. I followed their recommendation and subscribed to a new magazine called Sound Practices. It was unlike Stereophile or TAS in that, IMHO, it wasn’t advertising made to look like truthful reviews. It was all about following the Japanese audiophiles example and building/rebuilding Classic SET amplifiers and efficient horn speakers.

I ended up buying a custom built WE275A triode stereo amplifier (with volume pots as I didn’t own a pre-amp) from Don Garber (who used to share a shop with Herb Riechart and D. Komoro at “30 Watts Street“ in New York, I kid you not). I was playing an inexpensive Orelle CD player, that one of the usual magazines reviewed well, into the SET then small Klipsch speakers and did not hear the magic that I was regularly hearing at our Society meetings. I upgraded the CD player to transport and DAC, bought an Audible Illusions Mod 3 pre-amp then by-passed the volume pots on the 275A amp (with Don Garber‘s directions), replaced the Klipsch with Lowther speakers in BD-Design 150 Htz horns, etc. etc.

In the end I gave up trying to get “that sound” and started playing with modern speakers, SS amplifiers, and store bought cables.

 

[christensenleif@msn.com]

The problem was the impedance curve which I think was fixed in later examples. The designer used a solid state amp, and so only had caps to keep lows out of the smaller drivers. So it started at a nice impedance in the lows but as you went higher in frequency the impedance dropped as each additional driver was rolled in and thus in parallel with the LF driver. This is bad for SETs. Later I suspect he was convinced to put in a real crossover, which included coils and fixed the problem- resulting in a much flatter impedance curve.

I had AG Trios from 2000-2012 and the year before I ditched them, my friend and I did lots of measurements of impedance and frequency curves while trying to improve filter and even driver choices....
first with the std x/o the midbass horn had a good contribution up towards 2K and really messed up the midband
fixed that by a 15µF cap and then replaced the shitty Community 200 driver with TAD 4001 in original horn....BIG improvement
we went so far that at the end before ditch I only had a set of original magnetic frames with some cheap plastic horns on them and put them back to original and sold

 

[Rensselaer]

After some years with a nice little Leben valved integrated and phono stage, a Garrard 301 and Thrax Lyra speakers, listening to those same old same old records, the only ones that sound good with this set up, I decided to go back to my 1990 drive to put together a SET and Horn system that sounded as good as those I heard back in Oregon.

Today I have two vintage Altec A7-500 speakers, an Ayon Spitfire SET Integrated, a maxed out Garrard with MC cartridge, SUT’s and Ypsilon phono stage and am now getting the best sound I have ever heard from my own stereo, perhaps the best I have ever heard period. I can now enjoy all of my records and feel like I did that first time I heard a McIntosh playing through Klipsch Corner horns in the late 60’s.

 

[Ron Resnick]

Ha

hahahaha. You know ‘for a fact’ yours outperforms all SETs. I know ‘for a fact’ you’re wrong.

And no test bench ever made music. Measurements are a mere distraction used by disciples of such. What the heck they tell you about music reproduction is the sum total of zero

Please explain to us how you know for a "fact" that Atmasphere's belief that his OTL amplifiers audibly outperform SET amplifiers is wrong.

 

[morricab]

Please explain to us how you know for a "fact" that Atmasphere's belief that his OTL amplifiers audibly outperform SET amplifiers is wrong.

I think, Ron you are missing the sarcasm there because it is the same language that Ralph used about his OTLs being measurably and audibly better as a “fact” as well...didn’t see you challenging Ralph when he for sure said it with a straight face...if you are going to be impartial then you have to address both comments and not just the dealer/manufacturer gets the pass.

Ralph makes a lot of claims and when challenged seems to have misplaced a he evidence. Cableman took exception with his bold and unsubstantiated claim with an equally bold and equally unsubstantiated claim, which seems more tongue-in-cheek than Ralph’s clearly earnest claim.

 

[Ron Resnick]

Fair enough, Brad. I understand now. Thank you. I did not catch that in the groggy state in which I woke up.

Please know that I was not giving the dealer/manufacturer the pass. If anything, I was giving the benefit of the doubt to the generally thoughtful and decorous member (as opposed to the generally obnoxious and sarcastic member).

 

[andromedaaudio]

Measurements are a mere distraction used by disciples of such.

Measurements are used by people whos hearing is not good .

Same as a carpenter who constructs a house without a measure , same as a mechanic who has to align a coupling without a dial indicator or laser.

All the people who use tools are basically incompetent , thats what you re saying .
Luckily in the high end problems can be solved with cables , lol

Just about the only industry in the world , where you can get away with that

 

[PeterA]

I think, Ron you are missing the sarcasm there because it is the same language that Ralph used about his OTLs being measurably and audibly better as a “fact” as well...didn’t see you challenging Ralph when he for sure said it with a straight face...if you are going to be impartial then you have to address both comments and not just the dealer/manufacturer gets the pass.

Ralph makes a lot of claims and when challenged seems to have misplaced a he evidence. Cableman took exception with his bold and unsubstantiated claim with an equally bold and equally unsubstantiated claim, which seems more tongue-in-cheek than Ralph’s clearly earnest claim.

Brad you read my thoughts exactly. This is exactly how I saw it also. Nothing wrong with cableman‘s response.

 

[morricab]

Fair enough, Brad. I understand now. Thank you. I did not catch that in the groggy state in which I woke up.

Please know that I was not giving the dealer/manufacturer the pass. If anything, I was giving the benefit of the doubt to the generally thoughtful and decorous member (as opposed to the generally obnoxious and sarcastic member).

I don’t accept your bias towards the so-called thoughtful, decorous vs. So-called obnoxious/ sarcastic member. IMO, that is wrong and means you may (and did) miss something important, leading to a false conclusion.

 

[morricab]

Measurements are used by people whos hearing is not good .

Same as a carpenter who constructs a house without a measure , same as a mechanic who has to align a coupling without a dial indicator or laser.

All the people who use tools are basically incompetent , thats what you re saying .
Luckily in the high end problems can be solved with cables , lol

Just about the only industry in the world , where you can get away with that

These are false comparisons...but I suspect you know that..why peddle old and false tropes?

 

[Hear Here]

I think, Ron you are missing the sarcasm there because it is the same language that Ralph used about his OTLs being measurably and audibly better as a “fact” as well...didn’t see you challenging Ralph when he for sure said it with a straight face...if you are going to be impartial then you have to address both comments and not just the dealer/manufacturer gets the pass.

Ralph makes a lot of claims and when challenged seems to have misplaced a he evidence. Cableman took exception with his bold and unsubstantiated claim with an equally bold and equally unsubstantiated claim, which seems more tongue-in-cheek than Ralph’s clearly earnest claim.

Absolutely right. Both parties (Cableman and Atmasphere) are antagonised by any challenge to there "factually correct" belief that they are 100% right and, by implication, everyone else is 100% wrong!

I rather enjoy this nonsensical exchange between these 2 contributors! They both (in my opinion) rather deserve our ridicule - or perhaps we should just let them get on with it while we chuckle from the side-lines!

 

[andromedaaudio]

These are false comparisons...but I suspect you know that..why peddle old and false tropes?

They emerge every once in a while again because they are true , you cant keep them hidden .
I designed speakers in the beginning by ear as well .
But to design a accurate speaker (or horn ) you need measurement equipment