Direction of aftermarket fuses (only for believers!)


It is with reluctance that I start another thread on this topic with the ONLY GOAL for believers to share their experience about aftermarket fuses.
To others: you can call us snobs, emperors w/o clothes,... etc but I hope you refrain posting just your opinion here. If you did not hear any difference, great, maybe there isn’t.

The main driver for this new post is that I am starting a project to mod my NAD M25 7 ch amp for my home theater. It has 19 fuses (2 per channel, 4 on the power supply board, 1 main AC) and I will try a mix of AMR Gold, SR Black and Audio Magic Platinum (anyway that is the plan, I may try out some other brands/models). As it is reasonably difficult to change them, esp the ones on each channel module that requires complete disassembly, I would like to know what the direction is for these models mentioned and of course, others who HAVE HEARD there is a difference please share your experience on any fuse model you have tried.

Fuses are IME directional:
Isoclean is one of the first to indicate the direction (2008/2009) on their fuses. Users of HiFi Tuning (when the awareness rose quite a bit amongst audiophiles) have mostly heard the difference.

As an IEEE engineer, I was highly skeptical of cabling decades ago (I like the speaker design of John Dunlavy but he said on many occasions that cables nor footers matter at all, WRONG!). Luckily, my curiosity proved me wrong as well. I see the same skepticism that I and many others had about the need for aftermarket cables many, many years ago now on fuses and esp on the direction on fuses.

Another example is the direction of capacitors (I do not mean electrolytic types). Even some manufacturers now and certainly many in the past did not believe it can make a difference sonically. Maybe some do but it takes time in the assembly to sort and put them in the right direction/order (esp as some of the cap manufacturers still do not indicate "polarity") so that maybe is one argument why this is not universally implemented.








128x128jazzonthehudson
Great to hear. I did the same thing with my PADIS fuses: put them in and had questionable sound that didn't improve in a couple of days so I turned them around and viola!.

All the best,
Nonoise
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peter-s that is what I did in the beginning and it sounded great. And noticeably or a lot better than my littlefuse’s in the three places I put the SR fuses. Good enough for me to not worry if that is the right direction. And I did put one in at a time. If one sounded worse I would have turned them around and if it didn’t get better then I would have returned them. But as well as they improved the sound I couldn’t help thinking after, that was some of the best 360.00 I spent on my system.
 I just got the following message from Andy at synergistic research:
The current should flow from left to right as you read the fuse label (From “S” to “R”).
HE said unless you know what your doing so I would not interpret that as a slight to those who do.
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auxinput:

What a wonderful summary of your fuse experiments and the sonic results. I absolutely agree that these fuses have a major effect on the sound of a system and one's enjoyment of the music.

Because these fuses do change the sound, finding the optimal fuse for a single component can become time consuming.

If one does not want to do a lot of experimentation , I am suggesting auditioning the Synergistic Research Black fuse. I think it has some of the best sonic qualities available and as importantly comes with a 30 day trial or refund. They have improved both the digital and analog components in my systems.

David Pritchard

Ralph, how should I interpret this?
>> ^^ Do you understand how power cords are wired? If you get it wrong, Bad Things happen! 

Interpret is as: Don't mess with rewiring power cords unless you understand local code and know what you are doing!

Otherwise the power cord can become deadly as a shock or fire hazard!
Ralph, how should I interpret this?
>> ^^ Do you understand how power cords are wired? If you get it wrong, Bad Things happen! 

Al, I appreciate your urge not to jump to conclusion but isn't experimenting that got many further? Of course, one can just leave everything alone as GK alluded to and I do so when I believe there is no or little room for tweaking. 
What's next? The hearing of one differs from day to day, from mood to mood. How do you eliminate these parameters? 
We are not here to proof anything but to share our experiences. 

I do however agree with the settling time, be it electrical or mechanical or magnetical. 

As for cleaning as mentioned many times here on this very thread, I clean every contact regularly which is easy for access but I never claim that these actions have to do with directionality. 
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almarg
6,436 posts
06-08-2016 12:49pm
Some PC w/o shrink sleeves on plugs/IEC and thin threads like NordOst Valhalla can be tested, simply swap the ends. I may try that on my remaining Valhallas.
Although if that is done and a difference is heard, it by no means proves that directionality of the wires is responsible. For example, the act of simply removing and reattaching the connectors would seem to me to have a greater chance of being responsible. Assuming, of course, that care has been taken to eliminate other possible extraneous variables, such as differences in warmup state (many here have asserted that days of warmup may be required for some solid state equipment to achieve optimum performance), or the re-initialization that occurs in some designs (especially those which include digital circuitry) when power is removed and re-applied, or even (as some members here have asserted in other threads) the act of physically manipulating the cord, allegedly necessitating significant time for it to "settle.""

Of course, all of those "extraneous variables" you refer to can be controlled by the careful and thorough experimenter. There’s no reason to jump to conclusions. Looking on the bright side at least there’s no fuse holder to get in the way. Not sure I completely understand all the angst and concern over wire directionality since it rather easy to demonstrate it using stock fuses or unshielded interconnects. I can completely understand why uber skeptics would not wish to carry out these experiments themselves and report results. 

Cheers,

geoff kait
machina dynamica


Some PC w/o shrink sleeves on plugs/IEC and thin threads like NordOst Valhalla can be tested, simply swap the ends. I may try that on my remaining Valhallas.
Although if that is done and a difference is heard, it by no means proves that directionality of the wires is responsible. For example, the act of simply removing and reattaching the connectors would seem to me to have a greater chance of being responsible. Assuming, of course, that care has been taken to eliminate other possible extraneous variables, such as differences in warmup state (many here have asserted that days of warmup may be required for some solid state equipment to achieve optimum performance), or the re-initialization that occurs in some designs (especially those which include digital circuitry) when power is removed and re-applied, or even (as some members here have asserted in other threads) the act of physically manipulating the cord, allegedly necessitating significant time for it to "settle."

Best regards,
-- Al


^^ Do you understand how power cords are wired? If you get it wrong, Bad Things happen!

BTW, the effects of a power cord are much easier to measure than that of fuses. I've seen a power cord rob an amplifier of about 1/3 of its total output power!
>> I’d like to hear from AC power cord designers/manufacturers. Do any of them test the wire they make their cords with for directionality? They can't simply be reversed by the user though, of course.

Some PC w/o shrink sleeves on plugs/IEC and thin threads like NordOst Valhalla can be tested, simply swap the ends. I may try that on my remaining Valhallas.

BTW, I am finally testing the fuse and their directions on my NAD M25 using PADIS fuses and report back if they are indeed the Furutech OEMs. 
^^ Arcing is often audible with audio equipment. An arcing power switch can make quite a racket!

If you have arcing in an older house wiring system, failure of the arcing component (wall socket or the like) is eminent. It can also be a fire hazard.

Any connection has a certain amount of resistance. As current flows through it the resistance causes heat. A cold solderjoint will heat up faster than a proper solderjoint.

When a fuse blows, it will be warm or hot if you remove it at the time of failure. Its heat that blows a fuse. So it should be no surprise that any fuse runs at a temperature and that there will be a voltage drop across it. Keeping the voltage drop to a minimum by optimizing the contacts helps the fuse as it will run cooler since the heat it makes is supposed to be made by its internal element not its contacts.  

atmashere said:

^^ You won’t have arcing- that would be audible! A small amount of arcing has a way of turning into a lot of it in a short period of time...

Well that depends. On the AC mains side it depends on the size of the conductors and or the surface area of conducting contacts, bus, ect, and is directly proportional to the connected load passing through the arcing connection. Example say a branch circuit consists of #12awg wire. The continuous connected load is only 1 or 2 amps. The wall receptacle is old and the contact pressure is poor when a plug is inserted into the receptacle. Or maybe the receptacle is fairly new and the homeowner didn’t tighten down one of the terminal screws on the neutral or hot branch circuit conductors making a good solid connection. Can/could there be a slight small amount of series arcing going on with the 1 or 2 amp connected load? Would a 1 or 2 amp load create a lot of heat in the connection of the #12 wire to the side terminal plate/screw of the receptacle? Could the surface area of the #12 wire and the receptacle screw/terminal plate/contact, and male blade of the plug dissipate the heat? Now all bets are off if the home owner plugs in a big power hungry amp into the receptacle..... (Note: If the branch circuit wiring is protected by an AFCI breaker the arc fault sensing device of the breaker may/will trip the breaker open. It would depends on the amount of series arcing going on.)

Arcing can cause/create RFI and can be transferred through a conductor or through the air. Can it be audible through an audio system speaker?


On the power supply side of the secondary side of the power transformer.

Best example is a cold solder joint. Not in the main DC rails necessarily, though that would probably be heard through the speakers. In that event it would more than likely eventually burn itself free creating an open circuit. But how about an arcing cold solder joint in a circuit that does not consume a lot of energy?

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atmasphere
4,831 posts
06-01-2016 11:31am
Geoffkait: I hate to judge before all the facts are in but it appears your entire argument hinges on that statement, yet it is strictly hypothetical and specious.

To which Atmasphere replied,

"Not at all. I used the word ’might’ as with some fuseholders and fuses, the voltage drop stays about the same due to the alignment of the contacts. This easily explains why there are inconsistencies in reports."

Inconsistencies in reports? There are not inconsistencies in reports. Most reports are actually consistent.

Geoffkait: I also happen to be rather skeptical that anomalies in pressure or contact surface can actually explain the differences in soundstage, dynamics and tonality among other things that have been reported by many.

Atmasphere also wrote,

"Given your constant trolling, this such should come as no surprise. In your case I suspect its more profitable if the explanation remains mysterious and tricky to explain while using words like ’quantum’."

That makes no sense. The explanation is not mysterious. And I actually have not used the word quantum, at least not in this discussion. Are you afraid of the word quantum? Boo! Profitable? For me? Shirley you jest.

This whole discussion is an excellent illustration of the Backfire Effect, the phenomenon that occurs when someone clings to his original theory despite well constructed counter arguments and evidence to the contrary. The Backfire Effect becomes more and more pronounced as the evidence piles up, such that the person becomes more an more convinced in his mind he must actually be right.

have a nice day,

Geoff Kait
machina dynamica
advanced audio conceits
The Anti Cables discussion from their web site. Anti cables are unshielded.

"Wire Directionality?
As an electronic engineer I struggled with this topic for quite a while because it did not fit into any of the electrical models I have learned. It simply does not make sense that an alternating music signal should favor a direction in a wire. One of the great things about the audio hobby is that we seem to be able to hear things well before we can explain them; and just because we can’t explain something, does not mean it does not exist.

While wire directionality is not fully understood, it is clear that the molecular structure of drawn metal wire is not symmetrical and it is this physical difference which is consistent with which direction the wire sounds better. When the directionality is “backwards” there is a loss of resolution, cymbals sound like a spray-can and are truncated, voices are grainy and lack presences, and bass is less defined. When the wire directionality is “correct” the music is more relaxed, pleasant and believable. Once you hear the difference, you will never want to have to listen to wire backwards ever again.

All ANTICABLES products have the correct directionality marked with an arrow."

Nordost on the other hand apparently did not get the memo. From their FAQ page,

"When cables are manufactured they do not have any directionality. However, as they break in, they acquire directionality. Although the cable signal is an alternating current, small impurities in the conductor act as diodes allowing signal flow to be better in one direction over time. This effect is also called quantum tunneling, w hich has been observed in experiments over 25 years ago. Regardless of the purity of the metal used, there are still diode effects in all conductors. In addition, the insulation material will change when it is subjected to an electrical field."

cheers


Nice quote, Jea. I find the same thing when I quote mathematics. Everyone's ignorance trumps my expertise. Ah well.

jea48
2,095 posts
06-01-2016 7:31pm
"I’m reminded of a post by herman."

Quote:

"If you say the AC fuse blew because there was too much current flowing through it everybody nods in agreement even though that isn’t true. If you say the wire in the fuse melted because it got too hot after absorbing energy from the electromagnetic wave people look at you like you are insane and want to argue that vibrating electrons constitute current flow."

Interesting.

;-)



I’m reminded of a post by herman.

Quote:

"If you say the AC fuse blew because there was too much current flowing through it everybody nods in agreement even though that isn’t true. If you say the wire in the fuse melted because it got too hot after absorbing energy from the electromagnetic wave people look at you like you are insane and want to argue that vibrating electrons constitute current flow."




Post removed 
Jea48 wrote,

"Jmho, the differences heard in SQ is not from minuscule resistance of the fuse element inside the fuse that measures higher in one direction than the other, which is said to create a minuscule VD across the fuse element, measured in a live completed circuit from fuse end cap to end cap."

No one ever said or suggested differences in sound quality are due to the minuscule differences of resistance of the fuse element inside the fuse. That’s a Strawman argument. Even the independent tester for HiFi Tuning states on the data sheets that the very small differences in resistance DON’T EXPLAIN the (obvious) differences in SQ. All the resistance measurements are intended to show is that that ARE measurable differences, thus an indication that SOMETHING is going on. As I stated earlier on this thread somewhere and as HiFi Tuning intimates on the data sheets, distortion and noise measurements might be more uh revealing in terms of sound quality.

Geoff Kait
Machina Dynamica
no goats no glory
^^ You won't have arcing- that would be audible! A small amount of arcing has a way of turning into a lot of it in a short period of time...

Its easy to measure the voltage drop on almost any fuse in series with the AC line. There has to be one- as the voltage drop represents heat, and when the heat gets high enough that blows the fuse. IOW, the fuse is a resistance in series with the load.


I would add IF the contact between the fuse end caps and fuse holder clip/s contact/s are such that a VD can be measured (From fuse clip to fuse clip) then what else can/is going on in the poor connection? Maybe an ever so slight arcing between the fuse end cap/s and the fuse holder clip/s? If the fuse holder in mounted directly to the circuit board in close proximity of electronic components who can say if the ever so slight arcing can be sending/spewing out RFI infecting the electronics? Who can say if the arcing is causing a vibration on the circuit board? Is there is energy being created by the ever so light arcing? What impact might the energy create by the arcing have on the electronics of the piece of equipment.

Like atmashere said in an earlier post his preamp’s power suppliers are regulated so a small AC Line mains VD would not have any impact on the SQ of the preamp. But what if the connection between the fuse end caps and fuse clip/s was such that a VD existed, therefore maybe, an ever so small arcing was happening. So, what IF?

Jmho, the differences heard in SQ is not from minuscule resistance of the fuse element inside the fuse that measures higher in one direction than the other, which is said to create a minuscule VD across the fuse element, measured in a live completed circuit from fuse end cap to end cap.

I hate to judge before all the facts are in but it appears your entire argument hinges on that statement, yet it is strictly hypothetical and specious.
Not at all. I used the word 'might' as with some fuseholders and fuses, the voltage drop stays about the same due to the alignment of the contacts. This easily explains why there are inconsistencies in reports.

I also happen to be rather skeptical that anomalies in pressure or contact surface can actually explain the differences in soundstage, dynamics and tonality among other things that have been reported by many
Given your constant trolling, this such should come as no surprise. In your case I suspect its more profitable if the explanation remains mysterious and tricky to explain while using words like 'quantum'.
bdp24
1,256 posts
06-01-2016 10:08am
"I’d like to hear from AC power cord designers/manufacturers. Do any of them test the wire they make their cords with for directionality? They can’t simply be reversed by the user though, of course."

And the answer is...

Not all cable manufacturers agree on the dodgy subject of directionality. Here’s what Audioquest says on the subject:

"DIRECTIONALITY: All audio cables are directional. The correct direction is determined by listening to every batch of metal conductors used in every AudioQuest audio cable. Arrows are clearly marked on the connectors to ensure superior sound quality. For best results have the arrow pointing in the direction of the flow of music. For example, NAS to Router, Router to Network Player."

Addendum: One would expect in this day and age and in light of the fact that most high end cable manufacturers employ cryogenic treatment routinely (as do some aftermarket fuse manufacturers) that high end cable manufacturers are aware of directionality and have taken appropriate steps to deal with it. Whether that's true or not would take some research. For power cords, while they are most likely directional like all cables, though they employ stranded conductors, directional arrows are not used since they aren’t necessary for power cords.

cheerios,

geoff kait
machina dynamica
advanced audio conceits

Post removed 
I’d like to hear from AC power cord designers/manufacturers. Do any of them test the wire they make their cords with for directionality? They can't simply be reversed by the user though, of course.
Jim, I believe that Ralph was saying that he has observed a 2 volt difference in line voltage, as received by the circuitry in one of his amplifiers, to result in a 40 watt difference in the amplifier’s power capability. Not that any of his measurements across fuseholders were ever that large. And as I read his post he was providing those numbers for the purpose of illustrating how sensitive the performance of some components can be to variations in the voltage they receive.

Note that that reference was immediately preceded by this quote from one of your posts:
Millivolts...... If that was the reason, wouldn’t the same reasoning hold true for the AC mains line voltage feeding the fuse? In other words a small VD in millivolts on the mains feeding a piece of equipment could/would have an impact on the SQ of the piece of equipment. Not hardly....
And his response began with:
You are correct in your first statement of this paragraph.
Also, I recall him mentioning the 2 volt 40 watt figures, or numbers that were very similar, in a thread a few years ago that involved voltage drops across power cords.

I of course agree with the rest of your post just above. I would also point out that the greater the amount of current drawn by a particular component, the greater the effects mentioned in your last paragraph will be, everything else being equal. And of course different components will have differing sensitivities to those effects, as Ralph stated.

Best regards,
-- Al

atmashere said:

In one of our preamps I measured a 158mV (0.158V) drop; in one of our amps I’ve seen a 2 volt drop cause a loss of 40 watts at the output of the amp.


A fuse is one of those spots in that set of connections from the wall (AC power connectors, power cord and the fuse and holder) that is likely the ’softest’ which is to say that the sag occurs easier at that point, due to contact area and conductor size (the effects being limited by the fuse being so small). Part of this is due to the nature of the fuse itself, the other part due to its connection into the system.

When you said you measured a 2V VD (Voltage Drop) on an amp, I assume you are still talking across the line side and load side of the fuse clips of the fuse. Not across the actual fuse itself. I just want to make sure everybody here is on the same page.

As you know that is a perfect example of poor contact pressure and or corrosion buildup between the fuse end caps and the fuse holder contacts.

The greater the load on the poor connection can cause heat between the poor connection/s due to the resistance of the poor connection. More heat, more corrosion, more resistance, less contact surface area, more VD, when measured across the line-in fuse clip, and the load-out fuse clip connection....

Jim






Post removed 
Atmasphere wrote,

"Further measurement might show that by rotating the fuse in the holder the voltage drop can be altered."

I hate to judge before all the facts are in but it appears your entire argument hinges on that statement, yet it is strictly hypothetical and specious. Yes, further measurements might show..., but they also might not show. Then you are back at square one, dealing with the directionality of fuses and directionality of wires, why it exists and how to measure it. As I said on previous occasions you are overlooking or dismissing a key piece of evidence in this whole matter is the directionality of interconnects and why many cable manufacturers mark their (unshielded) interconnects (and other cables) with arrows to indicate the direction the cables should be connected. Furthermore, you apparently continue to ignore the best evidence available (since nobody else has stepped up to the plate) - the data presented on the HiFi Tuning website.

I also happen to be rather skeptical that anomalies in pressure or contact surface can actually explain the differences in soundstage, dynamics and tonality among other things that have been reported by many. As I also pointed out somewhere along the line contact enhancing pastes such as Quicksilver Gold applied to the contact surfaces of the fuse holder would eliminate the surface contact theory as a candidate, no?

Geoff Kait
Machina Dynamica
advanced audio concepts
Millivolts...... If that was the reason, wouldn’t the same reasoning hold true for the AC mains line voltage feeding the fuse? In other words a small VD in millivolts on the mains feeding a piece of equipment could/would have an impact on the SQ of the piece of equipment. Not hardly....
You are correct in your first statement of this paragraph. An important question might be 'what is meant by 'small'?' In one of our preamps I measured a 158mV (0.158V) drop; in one of our amps I've seen a 2 volt drop cause a loss of 40 watts at the output of the amp. In the case of the preamp the power supplies are heavily regulated so I do not expect to hear anything from a voltage drop on the line nor do we in practice. So we can assume that some types of equipment are far more sensitive to this issue than others!

The line voltage determinately effects the sound of a lot of equipment. This should come as no surprise to many of us here who have experienced the system sounding like Nirvana on one evening and the next day falling well short. So much has to do with line voltage which fluctuates, but also with how easily the line voltage can sag as the equipment is running (a further issue is distortion of the AC sine wave which is not part of this discussion).

A fuse is one of those spots in that set of connections from the wall (AC power connectors, power cord and the fuse and holder) that is likely the 'softest' which is to say that the sag occurs easier at that point, due to contact area and conductor size (the effects being limited by the fuse being so small). Part of this is due to the nature of the fuse itself, the other part due to its connection into the system.

This ties directly into the power cord conversation (a very real and measurable phenomena) and its effect on the system sound.

On a different website I encountered an individual who was of the objectivity camp (measurements) who was adamant that power cords could not make a difference in system performance. When challenged on the subject, I discovered he had never even tried to measure the performance of a power cord and thus had no measurements! To individuals who live and die by measurement, I appear to be a subjectivist; I found it quite ironic that he lacked the measurements while I did not.

I'm not sure how I come off on this site but to be clear I like to know why I hear certain phenomena and so try to see if its measurable. Quite often it is.

In this case, its a simple fact that you can measure the voltage drop across the fuse. Depending on the equipment in use and your measurement technique, you can see that voltage drop vary somewhat with the audio signal. It could be construed that this could introduce IM distortion.  IM happens to be audible to the human ear so it should come as no surprise that the effects of the fuse can be heard.

Our customers have been saying this all along as I have maintained elsewhere on this site. It took the obviously specious argument that the fuses were somehow directional to cause me to take a look at why people might think that. A simple DVM showed why and anyone who puts the DVM in AC voltage mode and simply measures across the fuse connections will see a number appear on the meter readout. This is not hard to do! Further measurement might show that by rotating the fuse in the holder the voltage drop can be altered. Sometimes you might have to reverse the fuse to optimize the contacts because the fuses we are dealing with are not always perfectly dimensioned so it might get better contact area in one direction as opposed to another. This does not mean that they are directional- it simply means they are not built precisely.
Post removed 

Hifi Tuning Supreme silver work well in both directions depending on taste on some music I tend to switch it round in the pre amp.

1 way sounds fuller with a large stage when direction switched things become tightly focused with a more direct presentation

I am using a 13amp syn research red fuse on my argentum powercord and switching round makes no difference to sound whatsoever

Jim, thanks for the extract from John Curl! From the electrical point of view, a VD should not matter much. Your comments was also incorrectly interpreted by me ( Al, thanks for the small but important addition of "THAN" ), hence my thought of possibly testing same brand fuses with different breaking points/capacities.

My best guess is that the vibration control/dampening (e.g. use of special liquids, beeswax, dampening material in Bussman) is a very important determinant, as well as the metallurgical composition and treatment (cryo) of fuse / fuse filaments. 



mapman
13,349 posts
05-27-2016 4:36pm
Yawn.

No. 13,349. Thanks for your input.  Are we keeping you up past your bedtime?
Just to comment that the way I read the voltage drops is not at all like some other folks, I.e., the naysayers. Here’s how I read them. The differences in voltage drops are not responsible for the differences in sound, they are intended to be only a clue that something is going on. If a fuse was electrically symmetrical wouldn't it measure exactly the same one way as the other? The fact is even the independent tester commented that the voltage drop differences don't correlate with the sonic differences heard in fuse directionality listening tests. I suspect if someone, and I’m not mentioning any names, were to measure *distortion* in the fuse or say *noise* then we might see some more uh convincing differences between fuse directions, not to mention between cryo’d and uncryo’d fuses. Therefore, I wouldn’t get too hung up on the obviously slight differences in voltage drops.

cheerio
Gs5556, well said IMO.  I've had occasion to make similar comments about those measurements in a number of other fuse-related threads, such as in a post dated 4-8-2016 in this thread.  An excerpt:

Regarding the measurements described in the HFT paper ... which purport to support the notion of fuse directionality:

1)Resistance measurements related to directionality were provided for 16 different HFT fuses, having current ratings ranging from 1.6 amps to 20 amps, as well as for a few competitive fuses and standard glass and ceramic fuses (the specific make of the "standard" fuses being unspecified). The differences in resistance for the HFT fuses in the two directions ranged from 0.000002 ohms to 0.000120 ohms. The differences in resistance for the competitive fuses were a bit greater in some cases, with the worst cases generally being the standard fuses, for which there was one isolated case having a measured difference of 0.005200 ohms.

IMO those numbers are so miniscule as to be:

(a)Laughable.

(b)Very possibly attributable to changes in the voltage of the battery in the measurement meter, from measurement to measurement (each measurement imposing a slight drain on the battery), and from minute to minute. Or if the meter was AC powered, to the very slight differences in AC line voltage that may occur from minute to minute, as various loads are turned on and off at nearby locations.

(c)Very possibly attributable to differences in contact pressure and contact area between the meter’s probe tips and the contacts on the fuse. The paper presents separate measurements of fuse resistance as measured in a fuseholder (for just one direction), indicating that the direction-related measurements were performed by touching the meter leads directly to the contacts on the fuse.

(d)Perhaps even contributed to by differences in the resistance of the measurer’s body, that would have been paralleled with the resistance of the fuse if he or she had fingers on the probe tips and/or the fuse contacts while the measurements were being taken.

(e)If Geoff’s comments about all wires being significantly directional are to be believed, then these differences would be totally swamped by both the resistances and the alleged direction-related resistance differences of the vastly longer associated wiring. In the case of mains fuses, that would include the power transformer and the power wiring in the component, as well as the power cord and the AC wiring in and outside of the house.

Best regards,
-- Al
 
Atmasphere wrote,

"Occam’s Razor has something to say here! Given that a fuse has to be used in AC circuits and given that people report differences by reversing the fuse, and also understanding how fuses are inherently incapable of having directionality in any way whatsoever, the explanation that they somehow have an effect by reversing them in the holder is a fairly complex explanation: some sort of unknowable, unmeasurable quality of the fuse itself."

i actually wouldn't be quite so hasty to dismiss fuse directionality out of hand. Let me give you exhibit A, interconnects. A certain kind of interconnect, one without a shield. The keen eared listener will discover that interconnects are directional, too. Just like fuses. Just like any metal wire conductor. This is precisely why many cable manufacturers mark their cables, the unshielded cables, with arrows, so that the cables are connected on the correct direction. Anti Cables marks their cables and they are just copper with lacquer covering. Audioquest and others mark their cables as well. Obviously some companies mark their cables with arrows only for the purposes of the shield.  If you have interconnects that don't have shields it's worth reversing them and seeing if that sounds better. I suspect this is true for both solid core and stranded. Speaking of which, the only way fuses or wire wouldn't be directional is if the conductor was some amorphous material like carbon or even lead, just for example, you know, non crystalline.

Hi Al,

Just read your post. I should have done a better job of what I was trying to say. After reading your post, I can see why Ralph took it the wrong way.


atmaspere said:

Its more than just millivolts- I can measure the effects with a 3 1/2 digit voltmeter. Mitch2’s suggestion by the way is excellent and is also measurable. Some fuseholders (like panel mount units) won’t allow this.

In response to my post:

Millivolts...... If that was the reason, wouldn’t the same reasoning hold true for the AC mains line voltage feeding the fuse? In other words a small VD in millivolts on the mains feeding a piece of equipment could/would have an impact on the SQ of the piece of equipment. Not hardly....

Your explanation makes more sense, at least to me, that the directionality of the fuse has to do with a VD, voltage drop, across the fuse element itself. That assumes the VD across the fuse would be measured in millivolts.

Millivolts...... If that was the reason, wouldn’t the same reasoning hold true for the AC mains line voltage feeding the fuse? In other words a small VD in millivolts on the mains feeding a piece of equipment could/would have an impact on the SQ of the piece of equipment. Not hardly....

Sorry if I was not clear. The resistance I was referring to is that of the fuse element itself inside the fuse. Not the resistance that can be created from a poor fuse to fuse clip connection due to corrosion and or poor contact pressure.

Jim

Took a look at hi-fi tuning measurements and they are meaningless. The data presented indicates the measuring instrument has a resolution of 0.001 milli ohm. The readings shows an average of 40 micro ohm difference in each direction.

That is the proof of directionality? Hardly. If the ambient air temperature should rise by 0.1 degree C as you change the probes around, that would be enough to close the difference to 10 micro ohms. Not to mention that the surfaces of the fuse contacts must be accurately milled for those readings to occur everywhere around the fuse. Not to mention the fuse elements have to be cut to the precise length and diameter each time.

If you hear a difference in one direction over another, you get no argument from me. But don't show me numbers and say this proves it.

Atmasphere 5-27-2016 12:57 pm EDT
I was not at any time suggesting that the holder was directional.
Yes, that was very clear in your post, Ralph.  It was also clear to me that Geoff's response represented a complete misreading of what you said.

Jea48 5-27-2016 9:17 am EDT
Your explanation makes more sense, at least to me, that the directionality of the fuse has to do with a VD, voltage drop, across the fuse element itself. That assumes the VD across the fuse would be measured in millivolts.
Jim, I believe that you inadvertently omitted the word "than" in the first line quoted above, and that you were intending to say:
Your explanation makes more sense, at least to me, THAN that the directionality of the fuse has to do with a VD, voltage drop, across the fuse element itself. That assumes the VD across the fuse would be measured in millivolts.
I wouldn't normally point out a seemingly minor omission like that, but with that word not included it took me a while to interpret your comment (with which I of course agree).

Best regards,
-- Al