Fuses that matter.


I have tried six different fuses, including some that were claimed to not be directional. I have long used the IsoClean fuses as the best I have heard. No longer! I just got two 10 amp slow-blows WiFi Tuning Supreme fuses that really cost too much but do make a major difference in my sound. I still don't understand how a fuse or its direction can alter sound reproduction for the better, but they do and the Supreme is indeed! I hear more detail in the recordings giving me a more holographic image. I also hear more of the top and bottom ends. If only you could buy them for a couple of bucks each.
tbg

Showing 50 responses by geoffkait

A fuse in the wrong direction should sound noticeably harsher and more sour. If you have more than one fuse of course listen to each fuse one at a time.
Tbg wrote,

"Geoffkait, I would be surprised if any true audiophile does (not) know this, but perhaps doesn't bother."

Uh, right. All 300 of them.
Bryon, you and Al think there are NON-QUALITATIVE reasons to believe fuses/direction can have audible effects? That's very interesting. Do you mean psychological reasons? Please expand.
Since the aftermarket fuses and cables come with arrows, there is obviously a predetermined method the manufacturers employ to control directionality during fabrication. This method most likely involves keeping track of the wire during the entire fabrication process, from rolling the metal to drawing the wires. If the fabrication process is not controlled, the probability that a given wire, fuse or cable will be inserted into the system with the correct direction is 50%. Since the crystal structure of the wire is not symmetrical after all the rolling and drawing, one direction will be noticeably more efficient for signal transfer.
It might be worth mentioning that this whole fuse directionality issue suggests a deeper, perhaps more disturbing problem, the inherent problem with all wires - they are all directional. The wiring in amps, interconnects, speakers, cd players, etc. One wonders what a system would sound like if the same care in fabricating the new breed of aftermarket fuses with respect to directionality was applied to all wires in the system?
The problem with the argument that "innumerable" people, even experts, are wrong is that there only needs to be one person, expert or not,that is right to prove the thing works. There are obviously many reasons why someone might not get the expected results, including impaired hearing, lack of listening experience, faults somewhere in the system, failure to follow instructions, etc. Thus, negative results mean precious little, except to support claims by naysayers that the device under test disobeys all known laws of science, is fraudulent, or is simply a placebo.
It's humorous to read this sort of thing, people getting all stressed out about a simple test. Why it's almost like superstition. I guess if you hear about placebo and expectation bias and unknown variables enough it'll psych anyone out.

Faint heart ne'r won fair maiden.

;-)
Almarg - Positive results don't mean anything to Skeptics, that much I agree with. Since it's probably true that anyone who hasn't tried one of these controversial devices, like aftermarket fuses, will be Skeptical of them - who wouldn't be? But for those who can hear the difference, who have tried them in their system, unde whatever test conditions they prefer, blind, double blind, A/B, whatever, then a Skeptic will have a difficult road to hoe trying to convince him that he didn't hear them. It's partly a question of how much you trust your hearing, how much experience you have listening, how developed your skills are listening.

B C - not sure why you use the word intuition, that appears to be your way of saying this whole thing is psychological. I am saying that at some point one has to trust his ears and saying, well, I'm not really sure what I heard. Even the manufacturer of Hi Fi Tuning fuses steadfastly refused, for many years, to believe fuses were directional, even his own. His theory was that fuses will eventually adjust to be "correct" no matter which direction they are inserted. About three years ago guess what? His fuses come out with those funny little arrows on them. He finally saw the light. You could say he was a reconstructed die hard Skeptic. By the way, fuse directionality is not difficult to prove, it's ridiculously easy. Any old fuse will do. Just reverse fuses one at a time and go with the direction that sounds best. Mystery solved.
It should be pretty clear that if you ask people what they think about controversial tweaks you're going to get a variety of responses. It should also be pretty obvious that Skeptics will always respond something to the effect, it can't possibly work, it disobeys all known laws of physics, it's the placebo effect, it won't pass a double blind test, etc. Don't you often find a Skeptic to be someone who pontificates from the comfort of an easy chair but who rarely, if ever, gets down to business and actually investigates the object of his pontification?

As I mentioned previously somewhere along the line, anyone wishing to indulge in armchair skepticism need look no further than Shun Mook Mpingo discs, Rainbow Foil, SteinMusic Harmonizer, those tiny little metal bowls, Schumann Frequency generators and many other devices. Controversial tweaks are controversial because they are not really subject to intuition. If they were they wouldn't be controversial.
Audiofeel, have you given any consideration to a long cold shower?
04-29-12: Bryoncunningham
Here are the putative explanations I've been able to find for why a fancy fuse might improve sound quality...

1. Lower DC resistance
2. Less voltage drop
3. Lower microphonics
4. More conductive materials
5. Better electrical contact between fuse caps and fuse wire
6. Better mechanical contact between fuse and clips
7. Better conductivity due to cryo treatment

For the folks who know about these things, do any of those seem plausible?

Of course they seem plausible. Well, with the exception of cryo treatment. Every skeptic worth his salt knows that cryo treatment is like hunting the snark, you can't see it and you can't measure it. But can you hear it? That's the question. Answer at 11.
"Well, if this is an issue of lower voltage drop or microphonics then I will pass, since my amp has line/load regulated power supply while case is made of solid billet of aluminum - not likely to vibrate."

Well, at least not at high frequencies.
Wrm57, The glass fuses sounded hard and edgy? Hmmmm, that's interesting, that's what fuses sound like when they're installed in the wrong direction.
I probably mentioned this before but if you have the original stock fuses in the component you can play the old reverse the fuse direction game to squeeze some more out of the system. All you need is a good set of ears. If the component has only one fuse reverse it's direction and see if the sound got better or worse. You can tell when the direction of the fuse is wrong when the sound is relatively harsh or strident and moore distorted. When the fuse direction is correct the sound will be more natural, with relatively less distortion and grain. If there are multiple fuses, reverse them one at a time, listening each time to see if the sound got better or worse. Sometimes it might be a close call, if it is leave the fuse as is and go to the next one. After all fuses have been auditioned for directionality repeat the procedure to verify. At the end of all this your sound should be considerably better than when you started.

"An ordinary man has no means of deliverance." - old audiophile axiom
One possibility why differences in fuse direction might be difficult to detect is that the speakers and/or other components that have fuses must be addressed as well. For example, if a given system has eight fuses and only two fuses are replaced with aftermarket fuses, there is a 50% probability that half the remaining fuses are not in the correct direction. So, one might reasonably conclude, assuming that fuse directionality is real, that distortion and noise produced by the remaining unchanged fuses are masking the positive effects of the two new fuses. There is also the real possibility that other undetected problems in the system are (also) masking the effects of the new fuses.
Bryon,  

Of course I would never say or imply that all of the points in Zen and the Art of Debunkery apply to all scientists or to any one person.  I think it would be a fair statement to say, however, that many of the "arguments" presented  in Zen and the Art of Debunkery actually do apply to many of the debates on audio forums, especially those concerning controversial tweaks, like the directionality of fuses or fuses in general. I suspect you will find many of the "strawman arguments" in ZATAOD are used commonly by Skeptics and OBjectivusts in these debates and other debates.  I do not intend to suggest anyone is in need of medical or psychological help just because they use fallacious arguments.  But it is what it is, I am only pointing out that such lines of argument exist here - whether intentional or not.

Almarg said,

"The assessment was conducted in a sufficiently disciplined manner to rule out the possibility of misperception, placebo effect, or self-reinforcing mass hallucination...

Zen and the Art of Debunkery:

<> If a significant number of people agree that they have observed something that violates the consensus reality, simply ascribe it to "mass hallucination." Avoid addressing the possibility that the consensus reality might itself constitute a mass hallucination.

The general idea of Zen and the Art of Debunkery is that that anyone, even a scientist, especially a renowned scientist, or a well-published scientist,  can sit in the comfort of his easy chair and attack a controversial subject, like directionality of fuses, or what have you, from a number of angles.  From a rhetorical perspective, i suppose this tactic can convince a non scientist his argument must be correct.  You know, the "old science is on my side" argument.  "I know a scientist and milk shot out of his nose when I told him what audiophiles believe."  lol

I suspect the arguments presented in Zen and the Art of Debunkery are probably intended to represent those who feel threatened - or feel that the scientific community is threatened - by something that cannot be explained, like UFOs - "It disobeys all known laws of science,  the people who report the phenomenon are either hallucinating, cannot conduct proper scientific tests, are easily fooled or are in need of medical help". 

The skeptical community and the scientific community are excellent in constructing arguments, including fallacious (Strawman) arguments, that appear to be intended to halt scientific investigation.  But Isn't the scientific method, especially investigation, the underlying requirement for arriving at the truth?  

Additional bullets from Zen and the Art of Debunkery for your consideration.

<> Label any poorly-understood phenomenon "occult," "fringe," "paranormal," "metaphysical," "mystical," "supernatural," or "new-age." This will get most mainstream scientists off the case immediately on purely emotional grounds. If you're lucky, this may delay any responsible investigation of such phenomena by decades or even centuries!

<> Ask questions that appear to contain generally-assumed knowledge that supports your views; for example, "why do no police officers, military pilots, air traffic controllers or psychiatrists report UFOs?" (If someone points out that they do, insist that those who do must be mentally unstable.)

<> Similarly, reinforce the popular fiction that our scientific knowledge is complete and finished. Do this by asserting that "if such-and-such were true, we would would already know about it!"

Geoff
Audiofeil, That's uncalled for. This is an audio forum, where sharing experiences is the primary objective and desire. I notice you have a pronounced tendency not to participate in meaningful discussions, choosing instead to fire off your usual snarky, sophomoric comments.
The assumption that differences in resistance are (solely) responsible for fuse directionality is most likely a false assumption, a strawman argument as it were. As would the assumption that differences in capacitance, if any are measurable, are (solely) responsible for differences in sound. These are precisely the same strawman arguments that skeptics of cable differences have put forth for more than thirty years - I.e., cables that measure the same must sound the same. Of course, any yutz with ears knows that's not the case.
Purity of metal, yes, and type of metal, whether the metal is alloyed with gold, whether the conductor is solid core or stranded, the geometry of the conductor (e.g., twisted pairs), the diameter (gauge) of the conductor, the color of the cable jacket, whether the cable is properly broken in, whether the cable has been cryogenically treated and what system the cable is inserted into. And finally the directionality of the cable.
Almarg, you said,

"The assessment was conducted in a sufficiently disciplined manner to rule out the possibility of misperception, placebo effect, or self-reinforcing mass hallucination..."

The problem here, methinks, is that you assume that nobody who hears the benefit of aftermarket fuses or fuse directionality is capable of conducting a proper experiment.  Zen and the Art of Debunkery might be of some help to naysayers in crafting arguments why fuses cannot be of much importance. Please find below a few examples for your consideration.

<> Put on the right face. Cultivate a condescending air that suggests that your personal opinions are backed by the full faith and credit of God. Employ vague, subjective, dismissive terms such as "ridiculous" or "trivial" in a manner that suggests they have the full force of scientific authority.

<> Portray science not as an open-ended process of discovery but as a holy war against unruly hordes of quackery- worshipping infidels. Since in war the ends justify the means, you may fudge, stretch or violate the scientific method, or even omit it entirely, in the name of defending the scientific method.

<> Keep your arguments as abstract and theoretical as possible. This will "send the message" that accepted theory overrides any actual evidence that might challenge it--and that therefore no such evidence is worth examining.

<> Reinforce the popular misconception that certain subjects are inherently unscientific. In other words, deliberately confuse the *process* of science with the *content* of science. (Someone may, of course, object that since science is a universal approach to truth-seeking it must be neutral to subject matter; hence, only the investigative *process* can be scientifically responsible or irresponsible. If that happens, dismiss such objections using a method employed successfully by generations of politicians: simply reassure everyone that "there is no contradiction here!")

<> Always refer to unorthodox statements as "claims," which are "touted," and to your own assertions as "facts," which are "stated."

<> Avoid examining the actual evidence. This allows you to say with impunity, "I have seen absolutely no evidence to support such ridiculous claims!" (Note that this technique has withstood the test of time, and dates back at least to the age of Galileo.)

<> Equate the necessary skeptical component of science with *all* of science. Emphasize the narrow, stringent, rigorous and critical elements of science to the exclusion of intuition, inspiration, exploration and integration. If anyone objects, accuse them of viewing science in exclusively fuzzy, subjective or metaphysical terms.

Cheers, Geoff Kait
Machina Dynamica
Almarg, you asked,

"Geoff, let me pose a simple question. When a seemingly absurd claim of sonic benefit from some tweak is offered, do you consider that there can EVER be a finite limit to its apparent degree of absurdity beyond which it is justifiable to dismiss the claim "a priori"?"

Well, what you consider absurd I or someone else might not. Onviously a lot of folks think many of my products absurd, while I do not, obviously. One of the points of Zen and the Art of Debunkery is the ease with which many well-educated folks dismiss mysterious or absurd ideas or phenomena. One might even say the more the higher education, the stronger the attitude, as I've intimated recently on this thread. Ironically, skeptics seem to be under the impression that the full force of science and the scientific community is backing them up. "Science will not allow it, it disobeys all known laws of science, etc. As if the skeptic even knows all thenlaws of science. Talk about absurd! Lol

As a skeptic, don't you think truth would be better served by actual investigation rather that idle speculation from the comfort of your Barko Lounger? You might consider taking a tip from PT Barnum who said, folks would be better off believing in too much rather than too little.

"A sufficiently advanced technology is indistinguishable from Magic." - Arthur C Clarke

Cheers, Geoff
Almarg, you said,

"To conjure up an example, suppose someone posts on the Internet that he has noticed that the sound of his system is significantly different depending on whether or not the TV set is on or off in the home of a friend living a mile away. He asserts that there is a cause and effect relationship between the two variables. Would you consider it unacceptable to dispute that claim without trying it?"

Of course, anyone can devise an absurd situation, but that doesn't mean mean all "absurd" audio tweaks are fabrications or impossible. If fact, your strawman argument, if I can be so bold to point out, is one of the illogical arguments presented in Zen and the Art of Debunkery. Even Bryon will certainly agree with me here.

Cheers, Geoff
Bryon, you said,

"Again, I agree. More importantly, UFO's exist! Whether they contain little green men is another question. But the documentation of UFO encounters is vast and incontrovertible. For a recent book that compiles the official testimony of dozens of military pilots, commercial pilots, radarmen, commanding officers up to the level of General, and others, see Leslie Kean's recent book. To the uninitiated, it's shocking. Most of the Ideological Skeptics I know won't read it! :-)
Bryon, you said,

"Again, I agree. More importantly, UFO's exist! Whether they contain little green men is another question. But the documentation of UFO encounters is vast and incontrovertible. For a recent book that compiles the official testimony of dozens of military pilots, commercial pilots, radarmen, commanding officers up to the level of General, and others, see Leslie Kean's recent book. To the uninitiated, it's shocking. Most of the Ideological Skeptics I know won't read it! :-)

I knew we'd finally agree on something. Lol. Would you believe I used to work right down the street from Operation Bluebook, the Air Force office investigating UFOs at Wright Patterson AFB way back when? You Tube has some Rather difficult to explain, highly entertaining videos of UFOs.
Mapman, you said,

"There are smart people here. Scientists and engineers. How about actually discussing some of your scientific breakthroughs in scientific terms rather than muddying the waters via logic based on non-facts?

One man's - or should I say one Mapman's - non-facts are another man's facts.

But You make a valid point - why don't I discuss my scientific breakthroughs here? You might not have noticed, but over the past 8 years or so there have been quite a few discussions about my products here on Agon. Unfortunately, as you might be aware, these discussions always lead to a train wreck. Make sense? Consequently, it just doesn't make sense for me to initiate discussions of my products. There was some discussion recently, so you might search the forum.

Furthermore, many of my products are proprietary. However, I provide the operational concepts of many of my products on my web site.

Cheers, Geoff
Almarg, you said,

"Scientific investigation and scientific progress draw upon a combination of observation, experimentation, analysis, technical understanding, and (dare I say it) reasoned judgment and common sense, among other factors. I see no reason for audio to be any different."

I see many reasons why this is different for audio. One need look no further that the cable controversy, now more than 30 years old, with no resolution in sight. Amplifiers with the lowest THD always sound better than one with higher THD, even 10 times higher. I implore you, is that reasonable, does that make sense? Extremely thin cables can sound better than much thicker ones. Again, does that make sense? Mpingo discs - how can one small 1 1/2 inch ebony disc in the room completely change the sound? It doesn't make sense. Green pens for coloring CD? Doesn't make sense. Schumann frequency generators that improve the sound? That's patently absurd. Intelligent chip with quantum dots improves the sound of CDs? Ridiculous. A cream that improves the sound of CDs or LPs when applied to the surface of the disc. Now, don't tell me that makes sense. Quartz, topaz, tourmaline and other types of Crystals for everything from cables and power cord plugs to room corners and electronics. Is that reasonable?

Tiny little bowls that improve the sound, even bass frequencies. I implore you, does that make sense? I'm afraid what we have is a revolution in how we look at the hobby of audio. Of course, we could ignore it, but doesn't it make more sense, and isn't it more reasonable, to take advantage of these new technologies to improve our lot?
"Machina dynamica? Not s much in my humble opinion. Sorry but thats what my "technical intuition" tells me. Just being honest."

I respect your opinion and appreciate your honesty - just curious, though, does your "technical intuition" come from a crystal ball or do you have a strong technical background? In any case, as I already intimated, I get a lot of comments like yours, completely understandable. No hard feelings.
Bryon, you're close...very close.
Mapman, you said,
"Yes I do have a technical background. A big part of my occupation is assessing technology and managing technical risks."

I don't really consider technology assessment or risk management to be technical fields, not that there's anything wrong with them. Even if your education and background were based on the hard sciences, you would still have a problem using technical intuition to determine the operational feasibility or efficacy of the controversial tweaks we've been talking about, like fuse directionality. Now, you might conclude it doesn't make sense, but that's to be expected, that's why it's controversial.

In the cases of things like Crystals, green pens, red pens, Mpingo discs, clocks that don't plug into the wall, PWB cream, low frequency generators, tiny bowl resonators, quantum dots, liquid cables, most audiophiles simply aren't prepared, education or background wise, to come up with an informed decision one way or the other. Technical intuition of the guy under the bridge is not going to be of much help when it comes to assessing many controversial tweaks. Someone with an EE or BS is not going to be much better off, since many of the concepts and technology involved with controversial tweaks cannot be found in textbooks.
"There are some products I have lower regard for than the MD products I have read about but it is truly hard to come up with many. Cigarettes are the ones that come to mind. Although I am of the opinion that the MD products are a sham, at least they are not hazardous to your health most likely. Then again who knows since as best I can tell nobody in this world is intelligent enough to understand how they work seemingly."

Mapman, thanks for endorsement. Your opinion means a lot to me.

Maybe you can do a risk assessment for me, whadda say?

You know what everyone in the world thinks? Interesting.

Tootles
Bryon, whatever happened to the word Terrific you used when you couldn't resist replacing the fuse in the preamp a few days ago? I was all set for a rave review. :-(. I still say wait a few days and re-evaluate the sound after the power cords break back in.

Geoff
Mapman, you said,

"SO it makes sense to me that resistance and voltage across different fuses varies somewhat and is not exactly the same. ....nothing new here."

Uh, Mapman, I think you better look at the data again. The data also shows measured differences were due to fuse direction. Hel-loooo! What does your intuition tell you about that data? Lol

Tootles
To all,

I would like to remind everyone that reversing the direction of existing, stock fuses can result in better sound. Of course the sound could get worse, it all depends on whether the fuse was initially installed in the "correct direction". This means that there is something inherent in the fuse wire that is producing the change in sound, since fuses are symmetrical. What could that something be? Well, since manufacturers of fuses and cables that have identified directionality of wire as being a real phenomenon have had to implement a strict control process for how the wire is fabricated, tracking the direction of the wire throughout the entire process. Ironically, this is true for Hi Fi Tuning, the owner of which for years insisted that fuses were NOT directional, that they would eventually break in "correctly".

If a manufacturer doesn't maintain strict control of wire direction during the entire process the odds are 50-50 that the wire direction will be correct. Pop quiz - Can anyone think of the reason why a wire becomes non-symmetrical during the fabrication process? Answer at 11.
On Page 4 of the Hi Fi Tuning data sheets, the following comment is made.

"The measurements done so far showed some measurable differences between fuse(s), but didn ́t explain completely the sonic differences between fuses."

Thus, there's no reason (for a skeptic) to hang his hat on either the resistance data or the noise data. It is actually a strawman argument, a logical fallacy, to protest that very low differences in noise and resistance proves, or is evidence that, differences in fuses and fuse directionality are not audible.

Cheers
Almarg, you said!

"What remains is anecdotal evidence. What I have said regarding that is that I suspect that SOME (but not all) of that evidence is the result of either failure to recognize and control extraneous variables, or system dependent effects that in other systems may make either no difference or a negative difference, or misperception."

I'm not sure what you refer to as "anecdotal evidence" can be so easily dismissed. I'm referring to evidence that the aftermarket fuses work, not how they work. The aftermarket fuses from Hi Fi Tuning, Furutech, Isoclean and perhaps others have been thoroughly reviewed in the press, usually with rave reviews. Every important audio magazine has reviewed them. There is also the evidence of many users of aftermarket fuses who have posted on the subject on a number of forums over the years. Could this really be mass hallucination, placebo effect, expectation bias, or some sort of tweak frenzy? I tend to doubt it.
Mapman, you said,

"Yep. No doubt it could be. Nothing has been proven as best i can tell. "

Nobody is saying there is proof or there even needs to be proof. But there is evidence, and plenty of it. This is all a little bit like the last holdouts in 12 Angry Men - "You can't prove he didn't do it," and "You can throw away all the other evidence."
Mapman, Of course there's such a thing as bias, nobody would disagree with that, but bias can be eliminated. You don't really think that all the positive reviews over the years, by experienced reviewers, and all the audiophile reports, also by experienced listeners, were the result of bias, do you? If so, you get the gold star for Skepticism.
Mapman, you said,

"Is fox news biased?

How about cnn?

These are major providers of news to millions."

That is an excellent example of a Strawman Argument. It is illogical to argue that because a news station is biased that all tests of an audio device or component are biased. I suppose that is a skeptic's wishful thinking. As I already pointed out, nobody is saying (expectation) bias does not exist in audio, it's just that bias can be eliminated as a culprit (by care in testing). Besides, the type of bias that appears to apply in this case is actually negative bias, since most skeptics like yourself and others are predisposed to believe the fuse cannot possibly work. You won't hear it because you psyched yourself out. Lol
Actually, I am not biased, not in the sense you mean. I am actually quite objective and scientific. I have a sneaking suspicion you're not quite ready to be a member of that club.
Hifitime, you make some excellent points regarding the measured resistance of the fuses. The same arguments can apply to be made to the measured noise as presented in the HI FI Tuning data. But I think this was really the point of the data - to show that the electrical characteristics, at least the two obvious ones they measured, of a fuse are not symmetrical (i.e., they are directional) and that the (very small) measured differences are NOT stufficient to account for the difference in sound, as Hi Fi Tuning is careful to point out. Essentially, you are agreeing with Hi Fi Tuning.

Next up for consideration, Things that are Too Small to have any impact on the sound. That should be fun!
Tbg said,

"As good as I thought the HiFi Tuning Supremes were, they are now much better. I had relied on the information I got from my amps' (BMC M1s) imported about the direction to be used as well as that of the HiFi Tuning importer on how to install the fuse. Friday I did an A/B direction testing. I had it in wrong."

Hmmmm...one wonders if Bryon Cunningham installed some of the fuses incorrectly during his recent testing of aftermarket fuses. If so, that might explain his less than stellar results. I suspect it would certainly help to know what an incorrectly installed fuse sounds like - noticeably harsher and more "electronic".
Unplugging a component from the wall and plugging it back in often results in a noticeable degradation of sound, if you're paying attention to such things, until such time as the contact between the plug and the wall socket has a chance to "reestablish" itself, which can take a few days or longer. In fact, Disturbing cables or power cords in any way should be scrupulously avoided IMO, especially during tests.

Geoff
Tmsorosk, what with directionality being an issue (except in the mind of skeptical couch potatoes) I have lost faith in ANY tests of fuses unless the person performing the tests is already familiar with the difference in sound fuse direction makes and unless he goes through the laborious procedure of trying each fuse in both directions as he proceeds. Not to mention the unplugging and re-plugging the power cord thing. There is a right way and a wrong way to get to the bottom of this thing.
Bryon, Ooops, I had forgotten you changed direction of the fuses.

Geoff
Did someone forget to put out the cockroach traps?
Bryon said,

"Then I decided to clean and apply Progold to every contact in the system, including the contacts on the power cords and IEC inlets. Now THAT was audible."

Well, I hate to judge before all the facts are in but I suppose there is some possibility that the unclean contacts masked the results of the fuse tests.

:-)
Bryon said, "That occurred to me, Geoff. But that ambiguity is present in EVERY listening test.

That's weird...all the reviews of Hi Fi Tuning and Isoclean Fuses in all of the major audio magazines are anything but ambiguous. For example, below find the conclusion of the Stereo Times review of Hi Fi Tuning fuses:

Conclusion
My time spent with both, the Ultra Systems HiFi-Tuning Fuses and Supreme Fuses over the years has equated to a audio life-changing experience. It’s impossible to tell if you will experience the same effects that I have since all systems are different, and my taste in music may be different from yours. However, I have not heard of anyone who’s tried these fuses utter anything but high praise. All I have heard were accolades expressing pure amazement as to how their systems have transformed with more focus, clarity, enhanced soundstage and transparency to die for.
Bryon, more grist for the mill is the recent review last year of the Supreme3 fuses from Hi Fi Tuning in Positive Feedback by Greg Weaver (a very experienced reviewer). Please note the use of the word, transparency. Coincidence? Not to mention the word, astonishing.

"After a brief bout of quite to install all eight fuses, I re-fired all my components to let everything have some time to "run in." Over the next three to three and a half weeks, I heard some exemplary, if subtle, improvements.

While I had expected some slight advances here or there, in a few specific categories, I was treated to small but encompassing, readily distinguishable, sonic improvements to virtually every attribute of my rig. The overall improvement wrought by their insertion was simply astonishing.

What stood out from the first was the notable enhancement in overall timbre, especially through the lower to mid bass, and the upper midrange through lower treble regions. Bass runs, from the thundering electric bass licks of the "Ox" Entwistle, to the engaging and often nuanced cello efforts of Janos Starker, were weightier, "woodier" sounding, and more tonally balanced. Strings, horns, and cymbals further shed most remnants of that "white-ish" sonic tinge and were rendered in a more fluid and coherent manner.

Transparency enjoyed a wholesale improvement; slight, granted, but bettered without question. This comes in two forms as I heard it. First, through the reduction of a miniscule yet inclusive fine graining, offering a more liquid texture overall, and secondly, by contributing to a slight reduction of the noise floor.

Spatial recreation enjoys special attention. Dimensionality takes on a slightly more focused nature, and at the same time, instrumental lines are recreated with better delineation and seemingly more accurate and appropriate size.

Both microdynamic events and microdynamic shadings are more readily revealed, unleashing enhanced detail and offering enhanced perception of physical and emotional involvement."
There is no one here who considers himself a naysayer who has tried any of the new fuses or fuse directionality. All of the folks here who have tried new fuses and fuse directionality have reported positive results. (Bryon is kind of an exception, since he cannot yet prove to himself that new fuses or fuse directionality are as important as everyone says.) The new fuses from various companies have been very positively reviewed in all of the major audio magazines for many years.

Logically, what can we conclude from all of this evidence? Answer at 11.

Geoff Kait, Machina Dynamica
Bryon, you're being argumentative again. I was simply pointing out that I have not accused you of wasting your time testing fuses. Why would I? But why would you say "you guys say it's a waste of time to experiment with fuses" unless you thought I was? Since I actually wasn't accusing you of wasting your time, your twisted logic notwithstanding, I have decided to let my strawman remark stand.

Geoff
Kijanki wrote,

"We don't even know if 3A Hi-Fi fuse is not really 3.5 or 4A standard fuse since AFAIK there is no test or approval of any agency."

Judging from the 4 pages of technical data on the Hi Fi Tuning web site, including data for directionality and cryogenically treated fuses, chances are good that Hi Fi Tuning testing is at least as comprehensive as UL or other standards orgs.