Live music, Tone and Presence: What most systems get wrong

[KeithR]

The key word in your opening sentence is "anecdotal". Most of his first watt stuff is making more 2nd harmonic anyway...especially the vaunted SIT amp, which is a single transistor per channel.

The whole point of my OP was that this unnatural "beauty", as you call it, was what I heard at the concert sitting less than 3 meters away from two cellos sawing away. It didn't remind me of ANY system I have heard that had a SS amp. Not one. Not Luxman Class A for sure...not Pass Class A, not Vitus...not.

Many top high end amps use a lot of feedback still: Soulution for one. The Class D mola mola for another.

Amp/speaker synergy does matter...especially if the amp has a lot of negative feedback and the speaker produces a lot of back EMF. That is probably more important than impedance per se or sensitivity.

Brad- have you read the paper? If you want to fully critique it, now that would be interesting. And this was done in 2008, not 1968. I'm curious if you agree with his thoughts on complex waveforms and IMD.

Harmonic Distortion and Sound

Many audiophiles believe that 2nd harmonic is to be preferred over 3rd harmonic. Certainly it is
simpler in character, and it is well agreed that orders higher than third are more audible and
less musical. However when given a choice between the sound of an amplifier whose
characteristic is dominantly 2nd harmonic versus 3rd harmonic, a good percentage of listeners
choose the 3rd.

I have built many examples of simple 2nd and 3rd harmonic “types” of amplifiers over the last
35 years. When I say “types” I mean that they used simple Class A circuits described as
“single-ended” versus “push-pull” and so tended to have a 2nd harmonic versus 3rd harmonic in
the character of their distortion, but were not made to deliberately distort.

Anecdotally, it appears that preferences break out roughly into a third of customers liking 2nd
harmonic types, a third liking 3rd harmonic, and the remainder liking neither or both.
Customers have also been known to change their mind over a period of time.

However the issue is partially obscured by the fact that the 3rd harmonic type amplifiers
usually have lower total distortion. Third harmonic usually appears with a negative coefficient,
resulting in what we think of as “compressive” - the example in figure 3. It's worth noting that
odd orders on nonlinearity also can be seen altering the amplitude of the fundamental tone
-something a distortion analyzer doesn't ordinarily display.

Audiophiles have been accused of using 2nd or 3rd harmonic distortion as tone controls to
deliberately alter the sound. I suppose that there are people who like it that way, but I don't
think this is generally the case. For reasons which will become clearer when we talk about
inter-modulation distortion, high levels of any harmonic become problematic with musical
material having multiple instruments, and the argument that 2nd or 3rd adds “musicality” doesn't
quite hold up.

 

[cjfrbw]

Nice post but I have a few comments/questions:

You mention a 3db increase in sensitivity bypassing the passive crossover...that would be double the power and not triple (you mention from 50 to 150 watts), no? Have you measured this 3db increase or is this somehow theoretical (please show me, I am curious about it).

What active crossover were you using for the Stage and Epsilon?

You are right about the more efficient ribbons but we found even at around 87db or so it works as well up to probably about 100db.

.

I also use the Accuphase F25, abeit in a four way configuration. i know you have stated objections to the F25 in the past, but I have always found it to be a boon and reasonably transparent and unobjectionable in my experience.

A 50 watt amp on the midrange ribbon and a 50 watt amp on the bass ribbon using an active crossover at 3db greater efficiency should theoretically operate like a 200 watt amp through a passive crossover connecting the midrange and bass ribbons. However, the midrange ribbon probably only requires less than half the power of the bass ribbon, so if you volume equalize the ribbons and standardize the efficiencies, the effect would be more along the lines of a 150 watt amp than a 200 watt amp. That would be a rough estimate. Even though each ribbon gains a 3db efficiency advantage, you really have more "extra" power on the midrange ribbon. So the midrange ribbon winds up being even more "drive-able" by SET than the bass ribbon.

Because of the power dividing differential with frequency range, an active crossover with a 75 watt amp on the bass ribbon and a 25 watt amp on the midrange ribbon would probably be more like a "200 watt" amp with a passive crossover.

I did not find that using a push pull tubed amp on the bass ribbon was better than using the SET on the bass ribbon. The point of using an SET is to get the fluid and open dynamics of SET along with the tone, and that always was better in my system when using SET on both the bass ribbon and the midrange. I have also made the observation reflected by some others that the push pull tubes I have heard tend to create artifacts and compression in the midrange compared to SET, which sounds so much more airy and open by comparison.

In response to another query, I have no idea what the specific current delivery of the 50 watt Wavac would be, since I was motivated by sound quality.

 

[morricab]

And what did you compare the 800 with?

Didn't compare. Sometimes people just listen to music, you know?

 

[morricab]

Brad- have you read the paper? If you want to fully critique it, now that would be interesting. And this was done in 2008, not 1968. I'm curious if you agree with his thoughts on complex waveforms and IMD.

Harmonic Distortion and Sound

Many audiophiles believe that 2nd harmonic is to be preferred over 3rd harmonic. Certainly it is
simpler in character, and it is well agreed that orders higher than third are more audible and
less musical. However when given a choice between the sound of an amplifier whose
characteristic is dominantly 2nd harmonic versus 3rd harmonic, a good percentage of listeners
choose the 3rd.

I have built many examples of simple 2nd and 3rd harmonic “types” of amplifiers over the last
35 years. When I say “types” I mean that they used simple Class A circuits described as
“single-ended” versus “push-pull” and so tended to have a 2nd harmonic versus 3rd harmonic in
the character of their distortion, but were not made to deliberately distort.

Anecdotally, it appears that preferences break out roughly into a third of customers liking 2nd
harmonic types, a third liking 3rd harmonic, and the remainder liking neither or both.
Customers have also been known to change their mind over a period of time.

However the issue is partially obscured by the fact that the 3rd harmonic type amplifiers
usually have lower total distortion. Third harmonic usually appears with a negative coefficient,
resulting in what we think of as “compressive” - the example in figure 3. It's worth noting that
odd orders on nonlinearity also can be seen altering the amplitude of the fundamental tone
-something a distortion analyzer doesn't ordinarily display.

Audiophiles have been accused of using 2nd or 3rd harmonic distortion as tone controls to
deliberately alter the sound. I suppose that there are people who like it that way, but I don't
think this is generally the case. For reasons which will become clearer when we talk about
inter-modulation distortion, high levels of any harmonic become problematic with musical
material having multiple instruments, and the argument that 2nd or 3rd adds “musicality” doesn't
quite hold up.

Yes, several times. I agree with most of it but quote about guitar distortion etc. is just his feelings talking with people no controls there. I think he does a good job of explaining that there is really more distortion there than people think. I cannot verify the math on the plots he has made since it is not clear what equations he has used to generate them.

 

[morricab]

morricab

Your recollection is also "anecdotal" there is no fact to it. It could be sincere but is is not factual. A point of view that I can only admit as being sincere. I remains nonetheless an opinion

You are right, my recollection is ancedotal. However, I have not put my musings in a white paper. The things I reference have at least some kind of hypothesis and controlled study. That is why I use them for reference rather than just "I think it sounds great because of X,Y and Z" or "Nelson also thinks it sounds good that way, although he has only stories like me".

The rest of the paper where he goes into distortion and calculations is quite interesting and tells a lot of the story but he doesn't get into controlled listening vs. the distortions illustrated so there is no correlation and therefore it limits the usefulness of his observations.

 

[morricab]

Nelson Pass thinks different - his anecdotal studies have a third of folks preferring 3rd harmonic. These are probably the same folks like Frantz that find an unnatural "beauty" on many SET amps. I have to admit my last two SET demos had me thinking similarly.

http://www.firstwatt.com/pdf/art_dist_fdbk.pdf

I'm not saying there is a right or wrong way - but I don't think its as simple as you think. I also don't think there is a THD arms race in 2016. Many high end amps use little to no negative feedback as well.

I also *strongly* believe in amp/speaker synergy and an amp that may sound great on one speaker, doesn't work on another. Luxman Class A, for instance, sounded like cream on my Zus - but works very well for Vivid speakers.

I never said it was simple. THose guys in the 1930s and 40s only got it partially right. The guys more recently got it more right and it was more thorough than Pass's paper...which is an interesting paper.

Depending on the nature of the feedback of the amp, there can be profound interactions. Impedance of course also affects current deliver and so on. So, I don't disagree with you about amp/speaker interactions.

 

[morricab]

I also use the Accuphase F25, abeit in a four way configuration. i know you have stated objections to the F25 in the past, but I have always found it to be a boon and reasonably transparent and unobjectionable in my experience.

A 50 watt amp on the midrange ribbon and a 50 watt amp on the bass ribbon using an active crossover at 3db greater efficiency should theoretically operate like a 200 watt amp through a passive crossover connecting the midrange and bass ribbons. However, the midrange ribbon probably only requires less than half the power of the bass ribbon, so if you volume equalize the ribbons and standardize the efficiencies, the effect would be more along the lines of a 150 watt amp than a 200 watt amp. That would be a rough estimate. Even though each ribbon gains a 3db efficiency advantage, you really have more "extra" power on the midrange ribbon. So the midrange ribbon winds up being even more "drive-able" by SET than the bass ribbon.

Because of the power dividing differential with frequency range, an active crossover with a 75 watt amp on the bass ribbon and a 25 watt amp on the midrange ribbon would probably be more like a "200 watt" amp with a passive crossover.

I did not find that using a push pull tubed amp on the bass ribbon was better than using the SET on the bass ribbon. The point of using an SET is to get the fluid and open dynamics of SET along with the tone, and that always was better in my system when using SET on both the bass ribbon and the midrange. I have also made the observation reflected by some others that the push pull tubes I have heard tend to create artifacts and compression in the midrange compared to SET, which sounds so much more airy and open by comparison.

In response to another query, I have no idea what the specific current delivery of the 50 watt Wavac would be, since I was motivated by sound quality.

The Accuphase is ok and I used it for quite a while. Its just now that I know what it does I wouldn't want to own it again.

Do you really think the crossover loses 50% of the power? Kind of depends on the complexity of that crossover doesn't it? I can't imagine such a large loss though.

I would agree with what you say about the PP tubes vs. SET. That has been my experience as well. An SS amp will give you something different but it will by harmonically "dried out" by comparison...might be tighter and punchier but not necessarily...depends on the quality of the output iron on your SETs.

 

[morricab]

We are a bit caught in a loop on this and it would be great to find some new ground here. The original premise promised that but now we seem to be just going over exactly the same territory as in so many threads that have tackled the unveiling of the magic in SET and for some also the potential compromises with SET.

You just can't fairly evaluate the qualities of an amp out of context with its speaker pairing. I don't believe that SET used in a less than ideal speaker partnership is likely to result in anything but a lovely but still less than ideal sound. It seems to me harder to undo the underlying musicality by putting SET into a less than ideal speaker pairing than it is to damage the overall sonic integrity of the presentation. That is to say SET is for me largely inherently musical but also not necessarily life like in all parameters of its presentation of sound. It is more obviously less life like on larger full range ribbons than it is on horns, or on other high efficiency boxes, or even on hybrid panels or panels run with subs.

It doesn't tend to smear the sound in the core of its range but this can often also be somewhat less convincing at the extremes. In an ideal pairing like with horns this is hardly noticeable because what it is doing right is just so right. Horns don't tend to show you the last fragment of minutiae. They give you the big picture and so much of it that you don't notice details nor feel compelled to look for them. Both horns and SET don't trip over when caught up in the flow of the music. They get out of the way of the music and just let it into the room.

Put the same amp on a set of ribbons and sure, the mid range is still wonderous (and sometimes a tad too wonderous given how it then highlights the slightly less wonderous extremes). Not only can that coherence issue be highlighted by the greater linearity and resolution of ribbons it will also be exacerbated by the traditionally more demanding load charactertics and considerably lower sensitivity of this type of speaker. Also, it's in the nature of full range ribbons to not just show you what is there but also to them remind you of what is so clearly perceived as missing.

What was a lesser constraint with horns becomes a much more obvious constraint on the ribbons. Not too say some very specific higher wattage SET with large iron can't do better at this but then for me the shift of valve types to get this also involves other compromises. In the end while it can be undeniably pretty it fails to make the partnering ribbons do what I feel they do best... coherency and wholeness throughout their range with a broad versatility in being fairly wonderful at playing many types of music.

Given that there are a couple of breeds of speakers that are fairly ideal for SET then enjoying the best qualities of this amp type isn't a problem. Like others here, I feel that SET and horns is the happiest of SET marriages and is so very easy to get engaging presence with some of the more natural and beautiful tonality possible. But I also feel that this marriage has other other very salient issues. Mainly that this combination in its purest iterations can then also tend to limit us to the types of music that will work best with them. A happy marriage in a very lovely musical niche.

"It is more obviously less life like on larger full range ribbons than it is on horns, or on other high efficiency boxes, or even on hybrid panels or panels run with subs. "

I would argue that this might be true but that has more to do with horn properties than the amps. You won't hear these other speaker types sounding more lifelike with other amp types. They mess up too many things for that.

"It doesn't tend to smear the sound in the core of its range but this can often also be somewhat less convincing at the extremes. "

Which SETs are you referring to? The last two to run through my house did the frequency extremes very well...and on conventional speakers too.

"Horns don't tend to show you the last fragment of minutiae. "

Really? Not sure about that. Having owned planars (magnetostat and electrostat) of many types and now horns, I would not agree with this. They are everybit as revealing but in a more physical and less ethereal way.

"They give you the big picture and so much of it that you don't notice details nor feel compelled to look for them. "

Again, Really? I find that due to the focus and projection that they make things more and not less intimate.


"Not only can that coherence issue be highlighted by the greater linearity and resolution of ribbons it will also be exacerbated by the traditionally more demanding load charactertics and considerably lower sensitivity of this type of speaker. Also, it's in the nature of full range ribbons to not just show you what is there but also to them remind you of what is so clearly perceived as missing."

WHat coherence issue are you referring to? I have found SET to sound more coherent than any other amp technology...one of the things I like the most about the sound. Are you referring to the "soft" bass and "soft" highs? I would again suggest that you broaden your SET horizon...it is not only 300B.



"Mainly that this combination in its purest iterations can then also tend to limit us to the types of music that will work best with them. A happy marriage in a very lovely musical niche.[/QUOTE]"

THis is simply incorrect, IMO. There is no limitation in this regard...I enjoy music from nearly all genres with equal pleasure. To be honest, rock music is one area where planars struggle because of lack of umph in the midbass. That tends to steer you towards Jazz and classical music. My SET/horn combo are killer with rock and electronic music.

 

[bonzo75]

Didn't compare. Sometimes people just listen to music, you know?

Yes but then they don't pass judgements on components.

 

[bonzo75]

"It is more obviously less life like on larger full range ribbons than it is on horns, or on other high efficiency boxes, or even on hybrid panels or panels run with subs. "

I would argue that this might be true but that has more to do with horn properties than the amps. You won't hear these other speaker types sounding more lifelike with other amp types. They mess up too many things for that.

"It doesn't tend to smear the sound in the core of its range but this can often also be somewhat less convincing at the extremes. "

Which SETs are you referring to? The last two to run through my house did the frequency extremes very well...and on conventional speakers too.

"Horns don't tend to show you the last fragment of minutiae. "

Really? Not sure about that. Having owned planars (magnetostat and electrostat) of many types and now horns, I would not agree with this. They are everybit as revealing but in a more physical and less ethereal way.

"They give you the big picture and so much of it that you don't notice details nor feel compelled to look for them. "

Again, Really? I find that due to the focus and projection that they make things more and not less intimate.


"Not only can that coherence issue be highlighted by the greater linearity and resolution of ribbons it will also be exacerbated by the traditionally more demanding load charactertics and considerably lower sensitivity of this type of speaker. Also, it's in the nature of full range ribbons to not just show you what is there but also to them remind you of what is so clearly perceived as missing."

WHat coherence issue are you referring to? I have found SET to sound more coherent than any other amp technology...one of the things I like the most about the sound. Are you referring to the "soft" bass and "soft" highs? I would again suggest that you broaden your SET horizon...it is not only 300B.



"Mainly that this combination in its purest iterations can then also tend to limit us to the types of music that will work best with them. A happy marriage in a very lovely musical niche.

THis is simply incorrect, IMO. There is no limitation in this regard...I enjoy music from nearly all genres with equal pleasure. To be honest, rock music is one area where planars struggle because of lack of umph in the midbass. That tends to steer you towards Jazz and classical music. My SET/horn combo are killer with rock and electronic music.

"
Lol - apogees beat the backsides of any horn on midbass and rock and kick drums. Justin actually listens to electronic and rock. I agree with you though, the apogees you heard with SETs might have sounded less than toy horns with SETs on the mid bass.

And yes, agree with Tao's other comments.

 

[morricab]

Yes but then they don't pass judgements on components.

Why not? I report what I heard. I don't need a comparison to tell if something sounds thin or unmusical. I have heard the Vivids in lots of other setups sounding much better...even with a Devialet.

 

[bonzo75]

Why not? I report what I heard. I don't need a comparison to tell if something sounds thin or unmusical. I have heard the Vivids in lots of other setups sounding much better...even with a Devialet.

So Joel, who rates the Ayon Orthos 150 highly, preferred the bridged Luxman to Ayon on Maggie 20.7 and his Vivids (he also preferred them to the Karan 1200).

I preferred them to the Ypsilon Aelius at his, and to the Viola symphony on the TAD (dealer had the same preference). But of course, your listening without comparison might be better researched since you are a scientist

 

[morricab]

"
Lol - apogees beat the backsides of any horn on midbass and rock and kick drums. Justin actually listens to electronic and rock. I agree with you though, the apogees you heard with SETs might have sounded less than toy horns with SETs on the mid bass.

And yes, agree with Tao's other comments.

Lol right back at you. You have owned how many planar speakers and how many horns exactly? I have owned numerous examples of planars and a couple different horns and what you are saying doesn't fit at all.

It was well known as well that planars don't deliver the "slam" of dynamic speakers. It was debated on various forums for the last 15 years. The planar argument was quality over quantity. That "slam" is not from deep bass.

I get far more impact from percussion with horns than all but the largest planars. My big Acoustats had slam and quality Even Apogee Full Ranges couldn't do this.

You also have to remember that we were all using big SS amps on our planars at one time because that was the orthodox view on how it should be done. We switched because it sounded better to most of us.

That said I think a good hybrid can work extremely well with a planar and that was my preferred way until I went to OTL and then SET. The Sphinx Project 16 is still probably one of the best amps for a 1 ohm Scintilla. Lamb M1.2 would be another good choice.

We tried my NAT Symbiosis on a pair of Relco Sinus One ribbon hybrids and that was VERY good. Of course the NAT was single ended. If that speaker was not so WAF unfriendly I would probably have bought it and kept the NAT.

 

[morricab]

So Joel, who rates the Ayon Orthos 150 highly, preferred the bridged Luxman to Ayon on Maggie 20.7 and his Vivids (he also preferred them to the Karan 1200).

I preferred them to the Ypsilon Aelius at his, and to the Viola symphony on the TAD (dealer had the same preference). But of course, your listening without comparison might be better researched since you are a scientist

And?? Your post is bunch of relativistic gibberish. You like this better than that on this but not that etc. Not one comment about the rightness of the sound. Maybe they all sound bad...but in different ways??

 

[bonzo75]

Lol right back at you. You have owned how many planar speakers and how many horns exactly? I have owned numerous examples of planars and a couple different horns and what you are saying doesn't fit at all.

It was well known as well that planars don't deliver the "slam" of dynamic speakers. It was debated on various forums for the last 15 years. The planar argument was quality over quantity. That "slam" is not from deep bass.

I get far more impact from percussion with horns than all but the largest planars. My big Acoustats had slam and quality Even Apogee Full Ranges couldn't do this.

You also have to remember that we were all using big SS amps on our planars at one time because that was the orthodox view on how it should be done. We switched because it sounded better to most of us.

That said I think a good hybrid can work extremely well with a planar and that was my preferred way until I went to OTL and then SET. The Sphinx Project 16 is still probably one of the best amps for a 1 ohm Scintilla. Lamb M1.2 would be another good choice.

We tried my NAT Symbiosis on a pair of Relco Sinus One ribbon hybrids and that was VERY good. Of course the NAT was single ended. If that speaker was not so WAF unfriendly I would probably have bought it and kept the NAT.

So maybe the problem is with the ones you owned?



And no, I wouldn't call the Odeon la boheme, which is a horn loaded cabinet speaker, a horn. But since you have been making any claims, that fits right in

 

[Zero000]

It was well known as well that planars don't deliver the "slam" of dynamic speakers. It was debated on various forums for the last 15 years. The planar argument was quality over quantity. That "slam" is not from deep bass.

I completely disagree with this. Fundamentally because it is rubbish.

This guy disagrees too. Read from the deep bass section at the bottom of the page to the bottom of the next page. Which oddly I agree with LOL

http://www.stereophile.com/content/apogee-duetta-ii-loudspeaker-anthony-h-cordesman#cQOjpdtCOVUfoQo8.97

 

[morricab]

So maybe the problem is with the ones you owned?



And no, I wouldn't call the Odeon la boheme, which is a horn loaded cabinet speaker, a horn. But since you have been making any claims, that fits right in

You wouldn't but the rest of the world would. Front or back loading it is still a horn. The tweeter is of course a horn as well.

Think what you want, if brands like Apogee, Audiostatic, Acoustat, Infinity, B&G, and Stax are the wrong ones then I guess you are right.

 

[bonzo75]

You wouldn't but the rest of the world would. Front or back loading it is still a horn. The tweeter is of course a horn as well.
.

Even this ad of the guy trying to sell it calls it a horn loaded cabinet. http://www.ukaudiomart.com/details/...peaker-pair-german-handcrafted-horn-speakers/

 

[Zero000]

Morricab - I think it is important to differentiate slam from punch. I do think that the mid bass "punch" of say mid bass synth drum that small surface area drivers with large excursion capability can deliver sounds rather different to the punch delivered from the lower excursion but very high surface area of an Apogee bass panel. It can't not do. But the "slam" of a well recorded drum kit is seriously well portrayed, for instance. As Ked said when listening last time to a high current amp driving my Duettas playing a drum solo "I don't think there's anything out there that can do that".

 

[morricab]

Even this ad of the guy trying to sell it calls it a horn loaded cabinet. http://www.ukaudiomart.com/details/...peaker-pair-german-handcrafted-horn-speakers/

The title says Horn Loudspeakers and it doesn't say cabinet it says back loaded horn construction.