John Curl's Blowtorch preamplifier part II

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My only comment would be that 'the truth' is not subject to democratic vote. History is full of masses that follow an idea or a belief that is later (when properly researched with 'the scientific method') proved to be false.

Jan

Of course --- no examples needed... goes without saying. Might be true might not be. Just keep an open mind about what people perceive. Never-the-less, me, myself and I did not make the claims.


-Richard
 
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Though those words were Walt's, I have no reason to think he just totally fabricated any of it. he is a credible person IMO. I think he believes what he wrote. I beleived him. And, so many people did cap upgrades by now, I tend to believe it is audible. But do I hear all these things Walt and other's hear? No, I do not.

In fact, I do not hear a lot of what others perceive. I did a cap comparison once in LA...... With the same mfr and only the plate material changed, it took us 4 hours to reach a consensus on if there was any difference. I'll tell you this... the difference is so small I dont care about it. IMO. Same with super reg PS. And, resistors. For my HPAmp, with the exception of 2 dale resistors, I used Radio Shack resistors and nothing special... electro caps and the THD is down close to -120dB and it sounds fantastic to me. Now, if I were to mfr it, I would use slightly better parts but not the finest on the planet. But that's just me. I am too practical for ultimate. JC owns that realm.

But, I still will not say no one can perceive what I cannot.


THx-RNMarsh

Very nice post, Richard.
 
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Wasn't it Buzz Aldrin who now is saying he saw some alien ship while up there?

Alien ship he said?

Recording tracks Russia's Moon gatecrash attempt - Science - News - The Independent

In that case, most probably, JC is spot on
Maybe Buzz uses his eyes, and not the scorn of his peers, to determine what is real. '-)

But there are countless other cases that he -like anyone of us- may be proven wrong (few humorous photos attached)


I'll tell you this...

Thank you Richard.
This is a successful earth landing report :)

George
 

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My only comment would be that 'the truth' is not subject to democratic vote.

Especially when the "democratic vote" is only from a tiny niche of hobbyists, and within that group, a self-selected group of them. It's like saying that one gives credence to UFO alien abductions because the majority of people who avidly read UFO Monthly and go to UFO conventions believe the same things. And how could they all be wrong the same way?
 
Well, I am a co-author of some scientific papers where my role was mainly to invent a new test equipment.

I don't know about you, but if my name is on an article, whether a scientific publication or a popular one, I am saying that I'm standing by what's in it. And if that article appears on my old company's website (and I'm getting money from them) as promotional material, I would feel like a total snake if I said, "Oh, that has nothing to do with me, I don't believe that stuff, how silly of you!"

But that's just me.
 
I agree that the "better looking" square response is an indication for a "technical better" amp considering stability issues. But I see strictly no evidence that the squareness of test signals must be the reason for you perceiving different sound quality. And by the way, these test conditions are far from being realistic.

I never said the appearence of the square wave test is the ONLY reason why I prefer one to the other, I simply listed it as one of the causes that was easy to see and perform. Besides, it is one of the VERY telling signs of stability, which is not necessarily a digital value of 1 or 0, before unhinging completely an amp might go therough the test with poor results, but still remain relatively stable and not trigger any sort of protection.

We would percieve that as changed tonality, easily checked by reducing volume. If it reverts into calmer waters, we have our basic culprit, the amp is not good for difficult loads - I hope we'll agree that is definitely not good and chalk it up as a fault.

Again, just one of several aspects I would want to investigate.
 
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I never said the appearence of the square wave test is the ONLY reason why I prefer one to the other,
Again, just one of several aspects I would want to investigate.
It seems obvious that, for a tweeter, there is a difference in the energy it receive if you feed-it with square waves instead of rounded ones.
Even if it is not able to follow the slew rate, it will accelerate harder.
I wonder why some could pretend that we need 0.0001% of distortion on one side, and pretend this difference in speed we can see is not perceptible.
Now, did the sources able to provide such square waves ? With analog tapes recorders, i have a doubt. With digital, it is possible, depending of the anti aliasing filters.
On my side, am-I crazy ? I take great care to the slew rate of my amps.
 
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Jay said:
You should know that they may never measured their cables. So explain it. For example something like: "typical 1 meter X AWG copper will typically have twice the reactance of 1 meter Y AWG silver". So you need to know more to explain the phenomenon, not to quickly say that the phenomenon doesn't exist.
Any competent cable will have series impedance sufficiently low that doubling it will make virtually no difference, and shunt impedance sufficiently high that halving it will make virtually no difference. Given this condition, there is nothing to explain. If this condition does not hold, then by definition the cable is faulty - however much you paid for it.

Esperado said:
I don't agree. At all. Cables DO sound different, because of they different characteristics (serial resistance, capacitance, inductance).
See above. If two cables sound different then at least one of them is faulty, or the equipment is faulty.

About "measurement is needed", i would say 'only if you need to put numbers on things'. Observation is what we do when we use an oscilloscope, and it is enough to figure out what is happening, most of the time, with a little experience.
Yes, if there are no numbers then no measurement has taken place. OK, I should broaden my requirement to include 'electrical observation' too.
 
Especially when the "democratic vote" is only from a tiny niche of hobbyists, and within that group, a self-selected group of them. It's like saying that one gives credence to UFO alien abductions because the majority of people who avidly read UFO Monthly and go to UFO conventions believe the same things. And how could they all be wrong the same way?

That is not an accurate description of the situation. The great debate is lasting for at least 45 years and it is not only a niche of hobbyists. Instead of that a lot of credible professionals including musicians, recording engineers and physicians did support the audible difference of controversial effects.

As i´ve said before, i have read about the idea to include controlled listening tests in audio in the beginning of the 80s (if i recall it correctly it was an article by Dan Shanefield that was my first encounter with this idea) and i considered it as convincing.
And that started my interest in controlled tests; as described the first attempts were quite amateurish (and if i were not been able to pass this first controlled blind tests i would have dropped the audio thing) and got more and more refined over the years.

But, and that was the reason to ask marce about the "proof" that would be accepted, having done such experiments with positive results does not help in discussions as the opponents were simply not accepting anything that contradicts their own beliefs.

It seems to be sort of misleaded bayesian approach, if someone beliefs that something can´t be heard, he will assign a zero probability to that event and nothing will be able to change this belief afterwards.
 
why isn't "the problem" equally that some "heard" differences in poorly controlled situations, internalized false correlations and won't budge, won't even try a better controlled listening test of their beliefs?

of course some of us don't begin to believe that that is anywhere near "equally" the case given the audiophile marketing amplifying the uncontrolled subjective impression side
 
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See above. If two cables sound different then at least one of them is faulty, or the equipment is faulty.
Since long years, i use compensating networks on all my speakers to get a flat impedance curve.
With a special attention to their resonance peaks. This was received with a lot of doubt and controversy here, as habit each time you bring something witch is not 'usual'.
But i can tell-you (again) it makes a big difference in sonic, and, one of the benefits, it kills a lot of the differences we can perceive between the same two cables used without those compensations.
 
But, and that was the reason to ask marce about the "proof" that would be accepted, having done such experiments with positive results does not help in discussions as the opponents were simply not accepting anything that contradicts their own beliefs.

Given that you've consistently refused to provide the normal sort of details on your "positive results" so that they can be evaluated and replication attempted, as well as full disclosure of commercial interests, it's not at all surprising that "opponents" won't accept your assertions.
 
Richard, I believe my hearing is still quite good, considering my age. That notwithstanding, I also can't hear at least one half of the differences reported from changing of this or that and having an improvement. I often see it as an imaginary effect, somebody is proud to have "outdone" the manufacturer, especially if it's followed by derogatory comments on the manufacturer (e.g. how could those idiots not hear that?). Very often, it's really an unfounded ego trip. Or not, and just because I can't hear it and nobody wrote a paper on that doesn't mean it's automatically untrue or questionable at best.

But that extreme has its counterpart in the "objectivist" camp. People who have to see it on a 'scope to believe it's really there. Asking a DIY person for written proof of what he's saying is equally idiotic if for no thaer reason than tha pople do that sort of testing to satisfy their own curiosity, only a few of them try to convince the world of their revolutionary contribution and it's this minority that's irritating.

I do not believe any single change of anything can produce large differences as improvements, only minor ones, with an oddball event here and there, which are too rare and too few to be more than just exceptions which confirm the rule. During all those years, I ran into a single component change which improved the device to the point that everybody heard it once - I regard this as a freak accident which simply proves that anything can happen, but I would never rely on it as a general rule.

Local insistence of published wtitten proof is therefore just an ego trip from those demanding it who cannot refute the thesis in any other way that to ask a man who just put together his second amp in his entire life for something they know he cannot produce in cases when the accpeted theroy and practice has been jeopardized. Also people who very probably do not hear too well, they know it and need proof that it can be heard.
 
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