PS Audio PWD MKII HiFi Tuning fuse direction

I use these fuses to excellent effect in my vintage Sansui tuners and directionality makes an obvious difference. Why would it make a difference on e.g., interconnects but not fuses?

Neal

Because interconnects sit in a DC circuit, where current flows in one direction. The fuse on the PWD sits in an AC circuit meaning the polarity switches 60x per second. How can directionality of a fuse make a difference when the direction of the current flowing through that fuse changes direction 60x per second?

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

I have hard time rationalizing directionality of cables and fuses, but in a DC circuit we can at least entertain the idea it makes a difference. In an AC circuit in my view it is categorically impossible there is a difference.

Why would it make a difference on e.g., interconnects but not fuses?

There are at least two relevant differences between the two situations:

1)Many interconnects are asymmetrical by design, having a shield that is grounded at only one end. The intent being that noise which may couple into the cable will be conducted to the output of the component that is driving the cable, and not to the destination component.

2)Most and perhaps all cable effects, at least those that are technically explainable, are proportional to length. Obviously the length of the conductor in a fuse is miniscule compared to the length of an interconnect.

Interconnects sit in a DC circuit, where current flows in one direction. The fuse on the PWD sits in an AC circuit meaning the polarity switches 60x per second.

Actually, the first sentence is not true. DC is a frequency of zero Hertz. While the circuit stages that generate and process analog audio signals are powered by DC, the analog signals themselves are a mix of AC components that are at many different frequencies, mainly between 20 and 20,000 Hz. There may be trace amounts of DC that are present for various reasons, but the speakers can't reproduce it and we can't hear it.

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.

Count me as being in the skeptic part of the spectrum, but with a mind that is not totally closed on this issue. 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. Not only to assure that perceptions were accurate, but to rule out the possibility that extraneous variables were responsible, such as contact integrity, warmup status of the equipment, changes in line voltage or noise conditions, etc.

Regards,
-- Al