PS Audio PWD MKII HiFi Tuning fuse direction

....I would, however, discount any reports of perceived differences in which the person did not go back and forth between the two orientations at least several times....

I personally would discount any reports that are not confirmed in double blind test, where the observer repeatedly picks the optimal orientation.

I totally agree with Al and Edorr, but for the sake of your peace of mind, Knghifi, install back to front as you noted in your op. This was discussed on the PS Audio forum.

Cheers!

_Ben

Almarg wrote,

"Some will say that fuses are directional because energy is being transferred through them in just one direction, or because during manufacture the conductive material they contain was "drawn" in a certain direction. Whether or not fuses in fact have any directional characteristics, the relevance of those facts is IMO speculative at best, and most likely unprovable."

I suspect one need look no further than the measured data for fuses of various types, including standard and HiFi Tuning, to see that fuses not only measure differently but are directional electrically.

http://www.kempelektroniks.com/Site_files/43/4300d6c0-5d8a-4774-bfde-f8b0088606b8.pdf

GK
MD

Hk_fan wrote,

"It doesn't make a difference in cables or fuses. Electrons do not care what arrow direction a manufacturer may put on a label."

Electrons don't carry the signal so I suspect we can probably rule that particular theory out. In fact, electrons in the conductor are kind of just sitting there, drifting along at a couple centimeters a minute.

GK
MD

The differences in directionality are only reported in a DC circuit. The AC measurement do not have a direction 1 and direction 2 measurement, because in an AC circuit there is no directionality. The flow of current changes direction 60 times per second.

Even the difference in directionality in the DC circuit are methodologically suspect.

First, the report does not say if the best measurement for the allegedly directional fuses correspond with the recommended direction. If you do two measurements there will always be a random difference between two measurements. To proof directionality, you need a batch of allgedly directional fuses, measure each one multiple time and show that the recommended direction measures better within statistical margins of error. There is no indication at all this is what they did. The report does not even say what the standard diviation is for the measurements, and therefore you cannot tell whether or not the differences are statisically significant or random.

Second, the difference between direction 1 and direction 2 measurement is higher in the non directional cheap fuses, than in the allegedly directional high end fuses. If the expensive fuses were explicitly designed to be directional, you would expect the exact opposite.

In conclusion, directionality of fuses in AC circuit is bogus, and in DC circuit highly suspect.