Stfoth, you’ve raised a number of excellent and sincere questions during the course of this thread. Regarding your most recent question...
Note, however, that for the reasons I stated earlier in this thread I for one do not totally rule out the possibility of wires (as used in cables) being intrinsically directional in **some** applications, to at least a small degree. In contrast to my opinion about fuses.
Best regards,
-- Al
Are the believers trying the fuses or wire switching at multiple times, trying to verify that the perceived result wasn’t due to one of the variables and trying to make sure the result is repeatable? As much as a skeptic might not even try it, might some believers not make the effort before advocating?... you may find the following excerpts from posts I’ve made in the recent thread on fuse directionality to be of interest:
Almarg 7-8-2017And also this comment in that thread:
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 [Atmasphere] 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:
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.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, 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.
Almarg 7-10-2017
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.
Note, however, that for the reasons I stated earlier in this thread I for one do not totally rule out the possibility of wires (as used in cables) being intrinsically directional in **some** applications, to at least a small degree. In contrast to my opinion about fuses.
Best regards,
-- Al