John Curl's Blowtorch preamplifier part III

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The missing link from my last post:

yu_ting_table2_exerptvcj8r.gif
 
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Indeed, Stanley Clark was found to sell mineral oil , not the real snake oil...basically snake oil is full of omega 3/6...so it should be at least an anti inflammatory medicine.If a small percentage of the poison is spread in its body, then the snake oil might indeed have some other properties as snake poison is used to made very effective medicines.
 
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Might be...it's not taken yet, but it's much easier to make high end products than hi-fi products.

This is over-long, but might be interesting for the perspective on old media tech:
YouTube

Just promised a good friend to look at his broken Spectral amp and found this looking sideways.

All good fortune,
Chris
For some weird reason all the respectable guys here launched their best products the same year i was born...JC, RF, JH...I already feel special.I wonder who launched me :)))
 
I can only judge on his writings and as he wrote:

"Since sheer quessing will yield the correct answer 50% of the time, a minimum of 12 trials is needed for statistical validity (16 is better,20 better yet)."

(Peter Aczel; The Ten Biggest Lies in Audio; The Audio Critic, Issue No. 26, 6)

which is nonsense. What you´ve quoted, is just opinon based on lack of information. Of course it is possible that he knew better but nevertheless wrote this nonsense.
You call it nonsense. As you described it, your own judgement, it's your own opinion, a biased one.

Wasn´t Peter Aczel also in the audio business?
Not everyone in audio business does what you do.
No, the evidence shows that the different test protocols have an impact on the response of the participants. Conjecture (partly) is the thinking about the internal mental processes that are the reason for these different response patterns.

See for example these numbers for an experiment from one of the mentioned often cited publications (attached gif). It shows the number of correct responses (expressed as percentage correct) for the various test protocols.

The same sensory difference (onedimensional) was presented to the same group of participants under three different test protocols as mentioned in the table. Samples presented in random order, retasting allowed, rinsing with water included. Graphic produced from: Yu-Ting Huang,Harry Lawless; Sensitivity of the ABX Discrimination Test; Journal of Sensory Studies 13 (1998) 229-239.
Just show the proof that level matched DBT of DACs or other audio electronic components in chain prior to speakers wasn't audibly distinguishable when the stress of DBT plagued the listener but when the stress is gone, it became distinguishable.
Nice advice in hindsight but unfortunately nobody told the listeners back then that they should train under the specific test conditions, that they need accommodation time and that positive controls are mandatory (negative controls as well).

Which publications i´ve cited in other threads on this topic do you have read? Don´t be shy, explain in detail where the authors failed to do propper work and were publishing just opinion and "conjecture"
Once again, you are just repeating your tried & failed shill tactic.
 
Yes, he lost credibility, and rightly so, when he favorably reviewed a speaker that he designed.

On Peter Aczel's Retirement - Audiophile Review
I recall reading that when it was published. It was the first I'd heard of "The Audio Critic" (I've not read many audio/hifi magazines other than The Audio Amateur). I found the dozen or so issues he had put online, read them, and it makes me want to read the others. From what I read he really was (other than the speaker as mentioned) a no-BS person, and one of the rare few in the audio publishing field.

I found this portion of one comment interesting:
As is often the case with extreme conflicting points of true the truth is usually somewhere in the middle. Most people who've conscientiously worked with audio know that (contrary to what Aczel) there are many audible differences between amps and preamps even though they don't readily show up in instantaneous switchover tests but are instead revealed over long term listening.

One could easily enough (okay, it would take some time and expense setting it up, but hardly more than a "real time" ABX test) set up two amplifiers with switching equipment (carefully level-matched, etc.) that selected one or the other, and only switched once every (for example - the time period could be something else) 7 to 14 days, and only when there's no signal passing through (perhaps it switches at 3 to 4AM, when no one is in the room so no one hears any relays or such). The date and time is recorded in internal memory, and can be recalled later, but the listener has no idea when the switchover(s) happen during the listening test. Could someone such as the commenter quoted above, after weeks or months of listening, hear the difference and recognize the switchover date(s)? And would this be something that could NOT be reliably heard in a "real time" ABX test?

From my reading of the recording professionals on rec.audio.pro 20 years ago (I learned to trust what they said they could hear, (sometimes I could verify it myself through audio files they posted), those who wrote about audible differences between various amps and preamps COULD tell the difference instantly, or at most in a few seconds. I don't recall anyone discussing differences only heard over the long term.
 
Jacob, I really admire your inexhaustible energy. :D

...all over the Internet, entirely dedicated to put down any attempt to rely on ABX for identification or preference tests, disregarding how carefully and throughout they are designed (e.g. there is always the “missing positive control” BS used when everything else fails).

To my long years experience on multiple audio related forums, it is useless to argue about (which, ahem, I’m just doing :D); you’ll always get back at best a theoretical word salad, lacking any practical suggestions to improve tests (if possible), if not nitpicking, obfuscating, etc... All while having little to no doubts and an unusual tolerance to casual (read: peeking) listening tests results. And always missing the “extraordinary claims require extraordinary proof” principle which is at the foundation of each and every experimental science.

To quote Jakob(X), “it is kind of sad”.

Vienna puts me in combative mood, I guess :D
 
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