Fuses fuses fuses

I'll vote to leave it up. Even though the thread is more concise than some other fuse-related threads that have appeared in the past (for example the "Fuses that Matter" thread that began in 2012 went on for 17 pages), arguments and rebuttals have been stated pretty thoroughly on both sides of the directionality issue. Taking it down would just increase the likelihood of a similar thread appearing in the future, with the usual protagonists then having to re-compose the same arguments.

Regards,
-- Al
 

It is a fact that jumping out of an airplane at 10,000 feet without a parachute is unlikely to have a happy ending, at least assuming that a very large net is not set up on the ground. To most of those having an extensive background in electronic design the idea that a fuse would be inherently directional seems about as probable as the likelihood of such a jumper being in condition to celebrate with a beer following the experience. Especially when a person having extensive background in electronic design (Ralph) has in this and other threads provided specific experimental evidence supporting an alternative explanation. And especially when another such person (me) has pointed out that a half dozen or so variables that are unrelated to the internal characteristics of a fuse are also being changed when its direction is reversed. And especially when the phenomenon is alleged to consistently occur regardless of the design and the function of the component that is involved, and regardless of whether the component has well regulated internal DC voltages or internal voltages that are completely unregulated.

The point to citing these things is not to deny anyone any pleasure. It is to dispel the promulgation of what appear to many of us to be myths and misconceptions, and to foster what appears to many of us, rightly or wrongly, to be a better understanding of the reported phenomena.

Regards,
-- Al

Excellent, erudite, and IMO entirely correct post, Terry.  Kudos!

Best regards,
-- Al
 

Geoffkait 7-20-2017
Of course, the real interesting thing in the fuse measurements was that listening tests correlated to measurements, i.e., the best sounding directional was ALWAYS the direction with least resistance.

A question:  Where do you see that?

The only reference to listening tests I see in the HiFi Tuning paper is the following statement, which has nothing to do with directionality:

For DC applications it ́s recommended to use the solder type fuse or the cryogenically treated fuses from HiFi-Tuning Germany. 
The drop in resistance up to the factor of 8 is clearly measurable and also could be detected in listening test.

Regards,
-- Al
 

Geoffkait 7-19-2017
However, there is no difference in the data sheets for resistance more than about 0.5%. Thus, your interpretation makes no sense, even allowing for language differences. You could be pulling my leg. Is this a lawyer trick? 😀

I would respectfully point out that the four numbers I clearly cited in my previous post, namely 4.6%, 3.8%, 4.4%, and 3.6%, are all "more than about 0.5%."

Regards,
-- Al

Geoffkait 7-19-2017
... as I already pointed out, ALL measured differences were about an order of magnitude less than 5%. NONE were anywhere near 5% so YOUR INTERPRETATION MAKES NO SENSE. If things were as you say then they could have said "in the range of of 10%%, fortifying their argument. Apparently I was correct, you never read the HiFi Tuning data sheets carefully.

Apparently you don’t read my posts very carefully. I have made the following statement multiple times in this thread (the statement even appearing in what you’ve quoted in your post just above), and also in other fuse-related threads in which you’ve participated:

In fact, all or nearly all of the directional differences in resistance were vastly smaller than 5%, with the exception of the "standard glass fuse."

The paper provides direction-related resistance measurements for two "standard glass fuses," which differ for the two directions by approximately 4.6% and 3.8%, if calculated by dividing the difference between the two numbers by the lower of the two numbers, or by approximately 4.4% and 3.6% if calculated by dividing the difference between the two numbers by the higher of the two numbers. None of those numbers, of course, are an order of magnitude less than 5%.

Regarding the meaning of "in the range of 5%," yes, in casual conversation among most Americans that would be equivalent to saying "generally around 5%," or "in the area of 5%." However given especially that the paper was presumably written by a German, and by someone for whom English is presumably not his or her first language, without particular knowledge of German linguistics it would be presumptuous to exclude the possibility that "in the range of 5%" might have instead been intended to mean the same thing as "within the range of 5%." Which all of the numbers were, of course, and consequently that interpretation would make their statement accurate. And note that I said that their statement was "arguably accurate," the word "arguably" having been intentionally chosen to leave open the possibility that the statement could be interpreted in ways that would make it inaccurate.

What’s bizarre, funny and ironic all at the same time is that you would pick an argument on this point since, you know, it kind of supports your position, not mine. Hel-loo!

My post was not intended to "pick an argument." That’s not how I do things.

Regards,
-- Al

Tim, see Atmasphere's posts in this thread dated 7-13-2017 and 7-14-2017.

Best regards,
-- Al
 

Geoff, regarding your question just above, in one of my posts here yesterday I had quoted the following statement I made in an earlier fuse-related discussion:

... all or nearly all of the directional differences in resistance were vastly smaller than 5%, with the exception of the "standard glass fuse."

However, note that what the paper says is "the difference is in the range of 5%," not "generally around 5%."   Differences that are "vastly smaller than 5%" are WITHin the range of 5%. So their statement is arguably accurate, although highly misleading.

Regards,
-- Al
 

Thanks, Ralph (Atmasphere).

I’ve been assuming that the "m" in the HFT paper stands for "milli." If in fact it stands for "micro" then the 0.000038 ohm figure that has been cited to illustrate how miniscule the differences are in their measurements for the two directions would actually be 0.000000038 ohms!

Although I’m thinking that "milli" may actually be the correct interpretation. For example this Littelfuse datasheet lists for their 3AG Series 313 glass-bodied 6.3 x 32 mm slow blow 2 amp 250 volt fuse a "cold" resistance of 116.9 milliohms. Which is very close to the numbers shown in the HFT paper for a T 2 amp 6.3 x 32 mm "standard glass fuse" if "m" is interpreted as milli and the commas in their numbers are interpreted as decimal points.

Fuses having significantly higher current ratings have much lower resistances, of course, with the resistance of the 10 amp Littelfuse in that datasheet indicated as 8.3 milliohms, which seems consistent with HFT’s measurements of their own fuses having relatively high current ratings. (Their paper doesn’t provide measurements of standard glass fuses rated above 3.15 amps).

Either way, though, I of course agree with everything else in your post, and it is consistent with and further emphasizes what I, some other members, and others who like yourself are designers of highly respected audio electronics have said here in various fuse-related threads.

Best regards,
-- Al

... you haven’t really read the HiFi Tuning data sheets very carefully, have you? 😛

The answer to that should be clear to those who have read one of my posts that I referenced here on 7-13-2017. That being the first of my posts dated 5-14-2012 in the "Fuses That Matter" thread, which appears near the middle of this page.

My response to your (silly) argument concerning precision of measurements, answer me this: why do the (small) measured differences ALWAYS correlate with the listening tests?  

0.000038 ohms doesn't correlate with anything (except perhaps for Mr. Modjeski's butterfly), and furthermore would be completely swamped by countless other factors, one of which I alluded to in item (e) of my post earlier today. I don't mean to be insulting, but anyone with a basic understanding of electronic design knows that.

Regards,
-- Al

P.S:  Thanks, Terry.  No problem if they've given the award to Ralph in perpetuity.  He's definitely earned it, over many years.

Geoffkait 7-16-2017
Mr. Smarty Pants - Why should there be any difference whatsoever in measured resistance if fuses are not directional? They should measure exactly equal. He’ll-loo! None of you Barko Lounger experts have figured that one out, eh?

If you are addressing me, Geoff, one of the quotes in my post just above clearly states three possible reasons, all of them related to sources of imprecision in the measurement process. The measured differences in directionality that were reported in the HFT paper were so miniscule that any or all of those reasons become legitimate possibilities.

And then a fourth possibility would be the butterfly that Mr. Modjeski referred to :-)

Regards,
-- Al
 

Geoffkait 7-16-2017 (quoting the HiFi Tuning paper)
There is a measurable difference in directivity of fuses. Mostly that will be due to the way the melting wire is manufactured. The difference is in the range of 5 % . That is in the range of variations due to the factoring process, but the difference is measurable with all types of fuses.

From the threads I linked to in my post above dated 7-13-2017:

Almarg
In fact, all or nearly all of the directional differences in resistance were vastly smaller than 5%, with the exception of the "standard glass fuse." However, even in that case, if per my comment and Roger's comments the OVERALL resistance for both directions is insignificant, the DIFFERENCE in resistance between the two orientations will certainly be insignificant.

Roger Modjeski
From the Tuning Fuse data sheet their 2 amp slow blow 5x20 fuse has a resistance of 24.077 milliohms in one direction and 24.115 in the other direction and 26.257 in the holder. If a butterfly flew by while the measurements were taking place we might see a bigger difference than the 0.038 milliohm difference in direction. Of course it might depend on which direction the butterfly was flying. But never mind, the direction measurements were made with DC and we are using these fuses in AC circuits. Perhaps if the butterfly flies clockwise vs counterclockwise there will be a difference.

Sorry I just had to put that in to keep up with all the humor that has been presented here.

[Note: 0.038 milliohms is 0.000038 ohms]

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

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....

.... Yet despite all that, and despite similar comments about the HiFi Tuning measurements that have been provided in numerous other posts going all the way back to the "Fuses that Matter" thread that began in 2012, Geoff continues to assert that the HiFi Tuning measurements support the notion that fuses are inherently directional.

Regards,
-- Al
 

Geoffkait 7-13-2017
Almarg, Roger appears to be just another outspoken but deluded amp manufacturer. Do you have a better example? 😬 Besides, you should know better than to use an Appeal to Authority. Does that work in court?

Geoff, I wasn’t using an appeal to authority in my previous post (although I would consider such an appeal to simply be inconclusive, rather than being illogical as you’ve often asserted). I was referring to specific technical points and analyses that have been presented here, which stand on their own regardless of who has presented them. And as it happens some of them were presented by me, as I mentioned.

For just a couple of examples, among many that could be cited:

See my post dated 5-17-2017 in the "SR Red Fuse" thread:

https://forum.audiogon.com/discussions/synergistic-red-fuse/post?postid=1425170

Also see the first of my posts dated 5-14-2012 in the "Fuses that Matter" thread, near the middle of this page:

https://forum.audiogon.com/discussions/fuses-that-matter/by_member?username=almarg

Regards,
-- Al

Geoffkait 7-13-2017
If it’s so easy to measure why don’t you or one of the other naysayers measure it? You’re just guessing. Why is it the folks that are already on board the fuse directionality AND Wire Directionality train are supposed to be the ones to measure it?

He did measure it, Geoff.  That has been stated or clearly implied multiple times in his posts and in excerpts of his posts I have quoted, including in this thread.

More to the point HiFi Tuning data sheets already show the measured the differences in fuse direction. Not just their fuses, all manner of fuses, including stock fuses, ceramic fuses, cryo'd fuses.

Those measurements have been totally debunked as being supportive of inherent fuse directionality, ***even if it exists,*** on innumerable occasions and in great detail in numerous fuse-related threads here, all of which you have participated in.  By me, by Roger Modjeski of Music Reference and RAM Tube Works, and by others.  Surely you remember?

Regards,
-- Al

Should i up the rating say from a 4 amp to 5 amp?

That’s been debated extensively in the "Synergistic Red Fuse" thread, with disagreement even among the technically-oriented people. Given that detailed information defining the technical parameters and blow characteristics of the SR and most other audiophile-oriented fuses is not available, and given also that the answer may very well depend on the unspecified surge currents ("inrush currents") that briefly occur when a component is turned on (which in turn will vary widely in both magnitude and duration among different components), there is probably no way to provide a definitive answer.

But FWIW the opinion I expressed in the SR thread was basically that the various reports of failures that have been posted (by at least seven people in the past year or two) suggest that a 5 amp SR fuse may actually be closer in its blow characteristics to a 4 amp "standard" fuse than a 4 amp SR fuse would be. Which if true would say that the rating that is used should be higher than the rating of the stock fuse. Others disagree with that philosophy, however.

Regards,
-- Al

P.S: Dave, thanks for the nice words. Best to you.

Careful, George!  You may find yourself accused of being "irrational," as I appear to have been in the second post following my previous post :-)

Best regards,
-- Al

First, to be sure it’s clear, the point of contention in this thread does not concern the efficacy of fuse upgrades. It concerns the OP’s question no. 3, regarding fuse directionality. And in that regard there appears to be a reasonably compelling body of anecdotal evidence, especially in the long-running Synergistic Red Fuse thread, that changing the direction of a fuse can make a difference, even if it is an AC mains fuse.

However, the problem is that establishing that changing the direction of a fuse makes a difference does not establish that a fuse is inherently directional, as many seem to automatically assume. One does not necessarily follow from the other, especially given Ralph’s empirical findings that I cited above (which he reported to be both measurable and audible), and also given that in the opinion of many of those having an extensive background in electronic design there is no means by which that is possible. As I put it in my post in the Synergistic Red Fuse thread that I referred to earlier:

[Inherent directionality in fuses] is fundamentally irreconcilable with any reasonable understanding of how electronic circuits work. Which is not to say, of course, that an understanding of how electronic circuits work can explain or predict everything about what we hear or don’t hear from our systems. It certainly can’t. But it can often help to provide a perspective on what does or does not have a reasonable possibility of being audibly significant.... And again, none of this is to say that I doubt the accuracy of most of the reported perceptions, it just means that in cases where those perceptions are accurate I believe that the cause was something else.

When the direction of a fuse is reversed all of the following variables, or at least potential variables, are being changed simultaneously:

1)Contact area.
2)Contact pressure.
3)Contact resistance.
4)Oxidation between the mating surfaces.
5)Warm-up state of the equipment.
6)Contents of "volatile" digital memory elements that may be present in the design (i.e., memory elements that don’t retain information when power is removed).
7)The states of other circuitry that may undergo re-initialization at turn-on.
8)Probably other variables that I haven’t thought of.
9)The direction of the element in the fuse.

In order to conclude and legitimately be able to claim that no. 9 is responsible for the difference that is heard, given especially what I and four different experienced designers of well regarded audio electronics have said in posts here which **strongly** point away from that possibility (again, see my post dated 10-28-2016 in the Synergistic Red Fuse thread), at the very least it is necessary to reverse and re-reverse the fuse multiple times, reinserting it each time with varying rotational orientation. To verify that the perceived difference is repeatable, and that it is not due to the phenomenon Ralph has reported, or to other variables.

And as I and Davehrab both said earlier, it appears that no one posting in any of the various fuse-related threads here who has claimed to have found that fuses are directional has done that. Which is understandable, given that significant time and effort would be required to do so with reasonable thoroughness. What is not understandable, though, to me at least, is failure to recognize that any of the other variables I listed may be responsible.

Regards,
-- Al

Are any of these aftermarket fuses UL listed?

Isoclean fuses, which are only made in slow blow versions, are indicated as having UL and other such approvals. Not sure if there are any other UL listed audiophile-oriented fuses.

Regards,
-- Al

Geoff’s statement above is correct. See the first of my posts dated 10-28-2016 in the long running "Synergistic Red Fuse" thread, in which I quote posts that have been made here by Ralph and several other designers of well regarded audio electronics on the subject of fuse directionality. I quoted Ralph’s comment (which had originally appeared in another fuse-related thread) as follows:

Ralph Karsten of Atma-Sphere:

… Fuses are inherently incapable of having directionality in any way whatsoever.

… I joined this thread recently with some results on testing. Those results are that the directionality appears out of coincidence and that actually greater improvement can be had by rotating the fuse in the holder for best contact…. Reversal is improving the contact area because fuse and holder are not dimensionally perfect and the fuse might sit better in the holder in one direction. By rotating the fuse in the holder without reversing it gets the same effect only more profoundly.

Also, in the numerous fuse-related threads that have appeared here over the years I can recall exactly two members who have reported experimenting with fuse rotation: Ralph, and a member named SGordon1, who posted in the Red Fuse thread on 5-3-2016 about having done that. Both gentlemen reported that significant differences resulted.

Also, as far as I can recall none of the many people who have reported hearing differences as a result of reversing the direction of a fuse have ever indicated that they went back and forth between the two directions multiple times, reinserting the fuse each time with randomly varying rotational orientation, to verify that their results were repeatable and that they were unrelated to rotational orientation.

Now, does it seem unlikely that rotating a fuse in its holder would have a reasonable likelihood of making an audibly significant difference? In the absence of empirical evidence, such as Ralph has provided, my technically-based instinct would be to consider it as being unlikely although possible. However, I would think it to be vastly more unlikely, and in fact impossible, for a fuse to have **inherent** directional characteristics, to an audibly significant degree. And as I mentioned, several other designers of respected audio electronics whom I quoted in the post I referred to above agree with me.

Regards,
-- Al