Double Blind tests *did* show amplifiers to sound different

[cistercian]

My school librarian did the same with Towers International Transistor Selector! Nobody had ever borrowed it before and I kept borrowing it. He also gave me about 5 years worth of Electronics Australia magazines. I still have them complete with the school stamp and binder ring holes punched through all the pages. I had to employ an early version of mental error correction on schematics where the holes (3 per page near the spine) took out component values.

Nice. I got several good books that way and a ton of technical magazines too. I bought many ARRL Handbooks over the years and found
them excellent for growing from tubes to transistors to IC's. I build very little now as I hate working with SMC's.
I miss components that were easier to handle!

 

[Frank Dernie]

I had to sell my big VTL monoblock amps when I left Chicago for Florida, heat just would have been too big a problem. Plus I had to sell all my old classic tube gear collection, just no room for it here. All I have left is a working 1925 Atwater Kent Model 20 radio, but I haven't fired it up in years, and a 1939 Zenith "Racetrack" radio, also working. I do fire that one up now and then to keep the caps formed and think back to the family who probably sat around it all through WW II listening to the Roosevelt "Fire Side Chats" and all the rest, a real bit of history.
I love tubes, brings me back to my mis-spent youth when I built a linear power amp for my CB using 4 6146s. Had to wait till late at night to use it, it would bleed thru all the neighbors TV and really tick them off, then they'd complain to my dad and I'd get a good wack. LOL
View attachment 77995

View attachment 77996

Gorgeous.
The power supply transformer and enclosure are famously the most expensive bit of a hifi to make but imagine how much these would cost today?
Just not having the knobs in line because of the straight pcb behind the facia is a joy in my eyes.
The Zenith case, in particular, would be too expensive for most manufacturers to consider today.
I wonder how many microprocessor controled surface mount devices will still be giving pleasure in the year 2100, not.

 

[DonH56]

Beautiful pieces, @Sal1950 . I don't have any real classics, just my old SP3a1 and an older Eico EL34 amp in a closet, somewhere. Blew up more than my fair share of 6146's between ham radio and CB "linyars". Have a few old books, including several tube manuals, but not sure where they are. I think the oldest I have out is my old ITT Handbook for Radio Engineers -- at least I think that's it, not in front of me now.

 

[FireLion]

@amirm ever come across this yoke? https://www.linsoul.com/collections/all/products/f-audio-am01

 

[Wes]

ok, I will follow this thread divergence...

was Atwater Kent considered a high end or quality brand in its day?


here is mine...

ne...

 

[b1daly]

I suspect it is not just a two step process but an iterative one at several interleaving bouts of listening/testing at different levels of characteristics.

Just a point of scientific process (electronics are not my area of expertise). Listening after knowing the measurements can set up a bias as well similar to sighted listening. So, it is better that you do the activity that is subject to bias first without the knowledge of data that might bias you. One cannot claim the invalidity of sighted listening while not accounting for the measurement data induced biases.

The example you have in mind is for detecting gross anomalies and there the order might not matter but if you are testing for which setting sounds better aurally (a much more subtle one), then you do not want that listening test to be biased by necessarily knowing the measurement results beforehand. Then you can confirm it later and if they were at odds, you investigate further. So the two work together rather than one being a substitute for another.

I look at some of the comments on the Okto threads about how they have been able to hear deeper lows or deep silences after they used the Okto. But they purchased it based on measurements. It is quite likely their hearing experience is biased by knowing the measurements because it sets up an expectation for what the measurements should result in. So what they are describing is consistent with the measurement but are they really hearing the sound or the measurement?

...

A listening test comparison done where you know the measurements of the amps is a ‘sighted’ test, not blind.

Knowing that a piece of audio gear has excellent measurements is a very powerful bias factor.

 

[b1daly]

Hearing differences between amplifiers isn't like alien abduction. The latter is attested to be a hand full of cranks; the former by hundreds of thousands of audiophiles worldwide.

I'm not anti-science. Good scientists know that all science is subject to revision. It's not us audiophiles who are the dogmatists, it's the-all-amps-sound-alike who are the dogmatists. (It seems to me it's the engineers who believe that science, their branch at least, is cast in stone).

I come to ASR because I believe that the differing measurements between, say, a Benchmark and a typical AVR are important to the sound. It's hard to understand why they would matter to an all amps sound the same dogmatist.

No one here has ever claimed “all amps sound the same,” that is a strawman argument.

What many people here, I would wager, suggest is that the bulk of differences that audiophiles perceive between amps are due to psychological bias, not objective differences in sound.

I suspect many people still cling to the idea that their perceptions of differences in sound between amps are based in real differences in audio performance because they have never even attempted a blind listening test with even a modicum of rigor.

But a substantial number of people have attempted such careful double blind listening comparisons and failed, including people like John Atkinson of Stereophile who have heard the “obvious” differences in sound between amps evaporate in a proper blind A/B comparison.

What’s incredible to me is that Atkinson apparently still thinks there are audible differences in amps that can’t be picked up in AB testing that manifest in long-term listening. This is a testament to how convincing the effects on listening perception psychological bias cause.

To argue that there are perceptible differences between amps that don’t show up in ABX testing is an extraordinary claim and I’m not aware of any evidence to back it up.

I highly doubt you would be able to distinguish between a Benchmark AHB2 and a comparably powerful AVR in the way you might suspect.

Benchmark makes a bit of a todo about a careful ABX comparison between their amp and a respected competitors amp that was conducted at a low power level. (.01 watt).

But this test was conducted with a sinewave. The audible threshold of distortion is much higher on a steady state tone. The fact that they do not tout a similar feat with real world audio sources (music, voice, movies) leads me to infer that they were not successful with such a test. Mainly because a result would be very notable in the objectivist audiophile world.

https://benchmarkmedia.com/blogs/application_notes/power-amplifiers-the-importance-of-the-first-watt

 

[Sal1950]

What’s incredible to me is that Atkinson apparently still thinks there are audible differences in amps that can’t be picked up in AB testing that manifest in long-term listening. This is a testament to how convincing the effects on listening perception psychological bias cause.

Never forget, JA's employment and the long term survival of Stereophile depends on the continuation of the subjective bible, everything counts.
A honest observation that most modern pieces like DAC's and Amps sound the same would then eliminate the need for a publication like theirs.

 

[sergeauckland]

Never forget, JA's employment and the long term survival of Stereophile depends on the continuation of the subjective bible, everything counts.
A honest observation that most modern pieces like DAC's and Amps sound the same would then eliminate the need for a publication like theirs.

And wipe out many dealers, who rely on people 'upgrading' to something that sounds the same.

S.

 

[Feanor]

No one here has ever claimed “all amps sound the same,” that is a strawman argument.

What many people here, I would wager, suggest is that the bulk of differences that audiophiles perceive between amps are due to psychological bias, not objective differences in sound.

I suspect many people still cling to the idea that their perceptions of differences in sound between amps are based in real differences in audio performance because they have never even attempted a blind listening test with even a modicum of rigor
....

In fact I agree that the difference audiophile perceive between amps, DACs, cables, cables with vs. without lifters, and "Brilliant Pebbles" are mainly due to psychological bias.

However certain members hear have bluntly said my observation about certain sound differences are, in effect, my imagination; (at least one apologized for insulting me). Unfortunately I can't prove they aren't my imagination (any more that they can "scientifically" prove that they are). As for that, if I claimed, (which I didn't), that my difference were based on blind testing, they would poohooed my blind testing as "lacking rigor".

Meanwhile I recently said that a Phase Linear 400 I owned for years sounded "like shiite", and I'm sticking with it.

Also meanwhile I'd like a one or two of the objectivists around hear to explain to me why SINAD difference between Benchmark, Ncore, Purify, or for that matter most AVR receivers matter if they are inaudible. Is it just nerdy perfectionism or what?

 

[sergeauckland]

Also meanwhile I'd like a one or two of the objectivists around hear to explain to me why SINAD difference between Benchmark, Ncore, Purify, or for that matter most AVR receivers matter if they are inaudible. Is it just nerdy perfectionism or what?

As a card-carrying objectivist, let me answer that. It doesn't matter one jot. It IS just nerdy perfectionism. It isn't audible so who cares.

I'll qualify that somewhat by saying that it takes some understanding of what the numbers actually mean and how and under what conditions they are measured, but if the tests are done correctly and with proper understanding, then yes, my statement above applies.

S.

 

[Sal1950]

Is it just nerdy perfectionism or what?

Doing the measurements holds the manufacturers feet to the flame by checking their work.
And there have been some products that have crossed the line into audible territory.
The exposure will improve the breed.

 

[Feanor]

As a card-carrying objectivist, let me answer that. It doesn't matter one jot. It IS just nerdy perfectionism. It isn't audible so who cares.

I'll qualify that somewhat by saying that it takes some understanding of what the numbers actually mean and how and under what conditions they are measured, but if the tests are done correctly and with proper understanding, then yes, my statement above applies.

S.

Thank you for your candor, Serge.

The nerdy perfectionism applies, of course, to the purchasers of the various top-performing amps -- at least those who are at the same time nerdy perfectionists, (other may hear unprovable SQ differences).

 

[Killingbeans]

Also meanwhile I'd like a one or two of the objectivists around hear to explain to me why SINAD difference between Benchmark, Ncore, Purify, or for that matter most AVR receivers matter if they are inaudible. Is it just nerdy perfectionism or what?

Yes

I'm pretty certain that I won't be able to hear the difference between most of the electronics that's been tested on this site, unless I let my biases take control of my perception. In my eyes, SINAD is mostly a testament to good/bad engineering, but as long as it's above something that won't be audible under normal real life conditions, I'm endlessly more interested in things like features, power delivery capability and in/output impedance.

The technician in me still gets a hard-on when I see a 120+ SINAD, but I'm perfectly aware that it's not rational

 

[BDWoody]

As for that, if I claimed, (which I didn't), that my difference were based on blind testing, they would poohooed my blind testing as "lacking rigor".

Not if it wasn't lacking rigor.

 

[cistercian]

Yes

I'm pretty certain that I won't be able to hear the difference between most of the electronics that's been tested on this site, unless I let my biases take control of my perception. In my eyes, SINAD is mostly a testament to good/bad engineering, but as long as it's above something that won't be audible under normal real life conditions, I'm endlessly more interested in things like features, power delivery capability and in/output impedance.

The technician in me still gets a hard-on when I see a 120+ SINAD, but I'm perfectly aware that it's not rational

I think that pushing for better performance is commendable and that advancing the SOTA is an excellent goal. I am an objectivist.

Of course, I reserve the right to choose equipment that may not measure well in sinad for other qualities I desire, like ample power
output. My Crown XLS 2502 measures poorly...yet I am delighted by it's high power to cost ratio and it sounds fine to me at high SPL.
Arguments can be made about what distortion or noise is problematic and at what levels it is problematic but such arguments
are unintelligible without accurate measurements to base them on. This site provides the data so a good decision can be made and
it pressures makers to step up their game. I think that everyone wins as a result!

 

[Sal1950]

Also meanwhile I'd like a one or two of the objectivists around hear to explain to me why SINAD difference between Benchmark, Ncore, Purify, or for that matter most AVR receivers matter if they are inaudible. Is it just nerdy perfectionism or what?

Kind of like buying a new 218mph Bugatti Chiron. Numbers you'll never, ever, need or use, but nice to know you possess them in any case.

 

[March Audio]

.

However certain members hear have bluntly said my observation about certain sound differences are, in effect, my imagination; (at least one apologized for insulting me). Unfortunately I can't prove they aren't my imagination (any more that they can "scientifically" prove that they are). As for that, if I claimed, (which I didn't), that my difference were based on blind testing, they would poohooed my blind testing as "lacking rigor".

No they haven't, that's just you getting stroppy because your view was challenged.

What has been said, repeating this for the umpteenth time, is that uncontrolled comparisons are likely to be faulty due to cognitive bias (amongst other reasons) Hence your opinions cannot be trusted to be accurate or correct.

Why don't you understand the difference between this and insulting you by saying it's all in your imagination?

It's damn tedious to repeatedly have this conversation with subjectivist who are determined to wilfully misinterpret what is said so they can justify their view as being valid.

 

[cistercian]

No they haven't, that's just you getting stroppy because your view was challenged.

What has been said, repeating this for the umpteenth time, is that uncontrolled comparisons are likely to be faulty due to cognitive bias. Hence your opinions cannot be trusted.

Why don't you understand the difference between this and insulting you by saying it's all in your imagination?

It's damn tedious to repeatedly have this conversation with subjectivist who are determined to wilfully misinterpret what is said so they can justify their view as being valid.

Hard core subjectivists cannot be used to evaluate performance. I have observed that I get a new set of headphones and that they
sound "different" to what I used before. Over time I get used to the new sound and then interpret it as the "correct" sound.
My ability to adapt to new equipment in this way is remarkable, so much so that if I did not have hard evidence in hand
(like the response curve of my RME ADI-2 FS) I would be completely lost. This effect is how quackery like super sonically pure
power cables and speaker cables can be sold to the gullible. Our perceptions can be filtered, biased, and inaccurate.

Being aware of how easily we can fool ourselves and how often we do it is the bedrock on which double blind tests are superior.

 

[Feanor]

No they haven't, that's just you getting stroppy because your view was challenged.

What has been said, repeating this for the umpteenth time, is that uncontrolled comparisons are likely to be faulty due to cognitive bias (amongst other reasons) Hence your opinions cannot be trusted to be accurate or correct.

Why don't you understand the difference between this and insulting you by saying it's all in your imagination?

It's damn tedious to repeatedly have this conversation with subjectivist who are determined to wilfully misinterpret what is said so they can justify their view as being valid.

Sorry, March. If you're tired of repeating yourself then don't do it.

I'm the sole judge of whether feel I'm being insulted. Regardless of a person's intent, when he/she speaks with condescension and hauteur I tend to take offence.