Master Thread: Are measurements Everything or Nothing?

[MaxwellsEq]

after 20 years of trying various amplifiers, i am absolute certain there is a tube sound to many valve amplifiers. i find it funny that alot of people in here say its just a placebo effect. sure alot of reviewers do have ridiculous claims, but you cant simply discard them all.

Who is saying on here that there isn't a tube/valve sound?

 

[Geert]

If you hang on until about 14 minutes, he talks about ASR.

You should know this guy got kicked out of the ASR forum more than a year ago .... Back then he planned to organize a controlled listening test, the only way to assure that what you're hearing is real, but he still didn't do that ...

 

[bloodshoteyed]

how come this thread's still up & running?

 

[killdozzer]

how come this thread's still up & running?

ASR is a beautiful place where everyone gets 2 pages of a chance!

 

[Booker]

Those who base decisions on measurements alone, and not ears think they are being scientific. It is actually the opposite. Since we hear with our ears, and not measuring tools, you must not leave out the most obvious measuring tool.

If you prove scientifically that an appraiser's ears can be part of a measurement system, it should not be a problem.
Refer to the attributive measurement system analysis, reach a match of at least 0.75 with two or three appraisers and then we can move forward.

 

[BDWoody]

very profound indeed

Profound enough to be added to the catch-all thread for wayward posts.

 

[pau]

If you prove scientifically that an appraiser's ears can be part of a measurement system, it should not be a problem.
Refer to the attributive measurement system analysis, reach a match of at least 0.75 with two or three appraisers and then we can move forward.

No it is actually the oppositete. You cannot prove anything scientitfically as there is no absolutes. You are limited with what is known and measurable.

In audio concept here, you are speaking very basic one point of view simplest possible sound measurements with limiteted measurement tools and understanding as human to say something like that.

You need to first prove that you can measure as complex as human hearing before you could stand behind your sentence.

 

[Geert]

In audio concept here, you are speaking very basic one point of view simplest possible sound measurements with limiteted measurement tools and understanding

I think it's your understanding of the relevant science and measurement capabilities that's to limited. The state of affairs is anything but simple and basic. There's more research available than you can read, and measuring equipment has a higher resolution than your ears.

If you don't agree, proof us via a controlled test you can hear things which can't be measured and you can be sure people will look into it.

 

[MattHooper]

Who is saying on here that there isn't a tube/valve sound?

For one, ASR member SIY has been proposing that "tube sound" is a myth.

Not that there isn't nuance to the position, but as I've understood it he believes not only that there isn't some common "tube sound" among tube amps, but also that most reports of tube amps sounding different - from SS or from other tube amps - are likely due to sighted bias. That seems to be his default, unless proven otherwise with blind test results. I hadn't come across someone with as much skepticism about tube amp sound until I read SIY here.

I'm happy for anyone to correct those impressions, if incorrect.

 

[Newman]

@pau your ‘philosophy in the absence of learning’ approach is outweighed by our ‘learning in the presence of evidence’ approach. Fundamental.

 

[MattHooper]

Profound enough to be added to the catch-all thread for wayward posts.

Which post are you speaking about? Thanks.

 

[MattHooper]

Ears (lots of them) were used by Dr. Toole (and others) to get us where we are today, and that was done in a scientific way (as much as that is possible). Now we know many things that allow us to draw some conclusions from measurements and data, that's for speakers, for electronics ears are needed only to enjoy the music, measurements can tell you most (near all) of the story.

As for trusting your ears, have a look at the wine, violins and what have you blind tests and the result there. Here is a simple video of something similar:

Yes, as I have argued: experiments showing how perception can be unreliable are important and have to figure in to our claims.

But so do all the examples of where our senses/perception are reliable. Which is, it seems, most of the time (e.g. reliable enough to navigate through the world day in and day out, to drive to work, recognize all the things we recognize etc). So for instance, if you set up a "test" table like the above, with a blue card and a red card on the table, and asked people to point to the red card when you said "red" and the blue card when you said "blue," with the exception of the colorblind or some other anomaly, most people would be able to pass that test over and over reliably. There would be countless such tests that people could pass easily 100 times in a row. Likewise for all sorts of tests discriminating sounds.

Any skepticism based on "our perception is unreliable" should be able to account for when our perception is reliable (enough) as well, and visa versa. Otherwise you may end up cherry-picking to support a viewpoint.

 

[Newman]

For one, ASR member SIY has been proposing that "tube sound" is a myth.

Not that there isn't nuance to the position, but as I've understood it he believes most reports of tube amps sounding different - from SS or from other tube amps - are likely due to sighted bias. That seems to be his default, unless proven otherwise with blind test results. I hadn't come across someone with as much skepticism about tube amp sound until I read SIY here.

I'm happy for anyone to correct those impressions, if incorrect.

Well it’s a better default position than a ‘sighted listening bias doesn’t exist unless proven by blind tests’ position. Which some people default to as a necessary defence of their professional integrity, ie their daily work involves making audio decisions based on sighted listening. Know anyone like that?

 

[MattHooper]

Well it’s a better default position than a ‘sighted listening bias doesn’t exist unless proven by blind tests’ position. Which some people default to as a necessary defence of their professional integrity, ie their daily work involves making audio decisions based on sighted listening. Know anyone like that?

No. I don't know anyone who argues for what you just wrote.

Still don't get it, huh?

(You'd think that my tag line featured under my every post would have been a hint for why you got it wrong, yet again....)

 

[Blumlein 88]

For one, ASR member SIY has been proposing that "tube sound" is a myth.

Not that there isn't nuance to the position, but as I've understood it he believes not only that there isn't some common "tube sound" among tube amps, but also that most reports of tube amps sounding different - from SS or from other tube amps - are likely due to sighted bias. That seems to be his default, unless proven otherwise with blind test results. I hadn't come across someone with as much skepticism about tube amp sound until I read SIY here.

I'm happy for anyone to correct those impressions, if incorrect.

I think the tubes aren't where a tube sound comes from if there is one. It is from transformers. I've not found tube preamps to have a sound. Those are wide band enough, and clean enough unless a broken design they don't color the result. It may be if blinded most tube amps aren't audible either. With some loads they alter response enough that is what you are hearing. I don't think SIY would disagree with that.

 

[MattHooper]

I think the tubes aren't where a tube sound comes from if there is one. It is from transformers.

I've often seen that proposed.

Since I don't have the knowledge to vet all these claims myself I have to do my best, looking at the big picture from all the discussions I've seen about tube amps from technically knowledgeable people. The views vary about how tube amps might alter sound, why and to what degree, just as there are differences among practitioners regarding what they feel is most important in speaker designs. I've observed that people with electronics knowledge/experience - and engineers in general - are influenced by both theory and practice in the form of personal experience. A lot of the disagreements, it seems, comes from the individual's personal experience when trying to put theory in to practice. Since everyone can't try everything, people will go down different rabbit holes, so naturally people will diverge in some of their conclusions. At least that's my take for one reason why many knowledgeable people still have different views, almost no matter what discipline
we are talking about.

I take SIY's view seriously, but not as the last word.

I've not found tube preamps to have a sound. Those are wide band enough, and clean enough unless a broken design they don't color the result. It may be if blinded most tube amps aren't audible either. With some loads they alter response enough that is what you are hearing. I don't think SIY would disagree with that.

Thanks. My impression is that he probably agrees with what both of us wrote. But I don't want to continue to talk about SIY's view - he can always clarify if he wants.

 

[pau]

I think it's your understanding of the relevant science and measurement capabilities that's to limited. The state of affairs is anything but simple and basic. There's more research available than you can read, and measuring equipment has a higher resolution than your ears.

If you don't agree, proof us via a controlled test you can hear things which can't be measured and you can be sure people will look into it.

@pau your ‘philosophy in the absence of learning’ approach is outweighed by our ‘learning in the presence of evidence’ approach. Fundamental.

I dont argue that you find differences with the measurements done and that it's not good thing, i just point out that when you say 'we proven scientifically x sounds better than y' it is purely not the case with just simple single measurements, tech involved, methods used and so on.

How can example a sinewave produce similar sound than compare to simphony that one could state the sound is proven scientifically better with device x. You can find differences for devices, but are the measured differences the only aspects of matter when you perform the test with a sample that is nowhere as complex as real?

I think you cant because the tests and measurements are done within the limits of what we can measure, often also simplified and streamlined because of the test backlog and somewhat biased to show the limits.

the path is right so it is all towards a better understanding. but still far from real science and understanding to such a bold statements.

 

[lashto]

I think the tubes aren't where a tube sound comes from if there is one. It is from transformers.

Does this have to be an either/or case?! To me it looks like a case of "from tubes and transformers"
And there is also OTL.

I've not found tube preamps to have a sound. Those are wide band enough, and clean enough unless a broken design they don't color the result.

The "tube sound" should be a timbre coloration coming from the HDs. And your observation about tube preamps having less "tube sound" seems to fit quite well because they usually have much less HD: 70-80 SINAD (or more) for tube-preamps, and 40-60 SINAD for tube-amps (even less for the no-NFB ones).
(note: I am not a tube amp builder or any sort of audio-expert, these are just observations from looking at lots of ḿeasurements)

You can also check Bob Katz's experiments with a (kind of) tube-preamp device. According to him the tube/H2 timbre is both audible and pleasant at about -60dB: "..it produces an attractive, warm, three dimensional quality with no apparent loss of detail or other side effects.."

It may be if blinded most tube amps aren't audible either. With some loads they alter response enough that is what you are hearing. I don't think SIY would disagree with that.

"most tube amps" might be too broad. Not even sure what would be considered a typical tube amp..

 

[Geert]

i just point out that when you say 'we proven scientifically x sounds better than y'

Who ever claimed that? We all now there's personal preference involved.

it is purely not the case with just simple single measurements

When Amir makes a Klippel measurement of a speaker, with the results used to depict frequency response, directivity, predicted room response, distortion and resonances, you would call that a simple single measurement? Do you understand the science behind that technology and the interpretation of the results?

For electronics like DAC's and amp's we measure amplitude, frequency, phase shift, power, linear and non linear distortion and noise. If needed we can also throw in a null test. So what 'single measurement' are you talking about?

You can find differences for devices, but are the measured differences the only aspects of matter when you perform the test with a sample that is nowhere as complex as real?

That's why we also do multi-tone tests.

the path is right so it is all towards a better understanding. but still far from real science

Everything mentioned above is based on 'real science'. If you can prove you can hear something that measurements can't explain then engineers or scientist will look into it and improve their methods.

 

[Ken Tajalli]

I think the tubes aren't where a tube sound comes from if there is one. It is from transformers. I've not found tube preamps to have a sound. Those are wide band enough, and clean enough unless a broken design they don't color the result. It may be if blinded most tube amps aren't audible either. With some loads they alter response enough that is what you are hearing. I don't think SIY would disagree with that.

To begin with, @SIY knows his stuff, specially when it comes to Tubes.
The transformer is an obvious target, since Tubes work in high voltage/low current environment which is not compatible with low impedance, current hungry speakers, so transformers are mostly needed. But as someone has already mentioned OTL tube-amps, where there are no output transformers, if you can find a decent one, some of that prejudice against transformers gets confirmed.
However, it is not just one thing, and if I was to choose one thing above all to blame for Tube sound, it would be design and/or manufacture.
Tube amps tend to have simpler circuits, so some component's quality can contribute too (to the tube sound).
But in a nutshell, theoretically, @SIY is correct.