PS Audio PWD MKII HiFi Tuning fuse direction

Al, I agree that the measured differences are relatively small compared to what one would expect (to explain the sonic differences heard by users). The manufacturer admits in the text of the data sheets regarding Noise that, "The measurements done so far showed some measurable differences between fuse(s), but didn’t explain completely the sonic differences between fuses." In other words, the manufacturer hears significant sonic differences between various types of fuses. As for fuse directionality, the manufacturer, HiFi Tuning, used to be adamant in his belief that fuses, in particular HIS fuses, were NOT directional - that no matter which direction the fuses were inserted they would eventually Break In to yield the same results. But at some point he changed his mind completely. One assumes he then had to learn how to keep careful track of the wire orientation as it travels through the fabrication process so that by the time the wire winds up inside the fuse the direction of the ARROW on the fuse body is correct.

Edorr wrote,

"Geoff, again, the difference are measured in a DC circuit."

I never suggested otherwise.

"AC current switches direction 60 times per second. Even if the fuse is directional, you would not hear it in an AC circuit."

I never said you would. But, really, what harm could there be in trying both directions, anyway, even in a DC circuit? Stranger things have happened.

"The paper does not even suggest you would."

I never suggested otherwise.

"So lots of reasons to be skeptikal about claims of hearing directionality differences in an AC circuit."

I guess the only way to be sure is try the fuse in both directions in an AC circuit. Better safe than sorry.

Geoff, the poster specifcally asked about application of a (directional??) fuse in an AC circuit.

If something can be categorically ruled out on undisputable theoretical basis, I personally would not advocating trying it anyway because "stranger things have happened" and it is better to be "safe than sorry".

If you take this philosophy to its logical consequences, all bets are off. For example, you could consider moving your DAC to other side off your audio rack and hear if it makes a difference. You should also try the black and silver version of any given component before deciding what to buy...

Edorr wrote,

"....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 think the differences should be obvious to any Yutz with ears right away. But if the listener is hearing challenged or the system is not up to snuff, it won't matter how many A/B tests are performed.

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

I did not see that coming. One wonders, have you ever actually had to sit through one of those double blind tests? Who can sit still and pay attention long enough to get through all the repeated tests? Unplug the power cord, take top off the component to access the fuse, reverse the fuse direction, screw the top back on, plug the power cord back in, listen. Repeat 10 times. LOL

Edorr wrote,

"If you take this philosophy to its logical consequences, all bets are off. For example, you could consider moving your DAC to other side off your audio rack and hear if it makes a difference. You should also try the black and silver version of any given component before deciding what to buy..."

Of course you can come up with all sorts of absurd examples. How difficult is it to try the fuse both ways? What are you afraid of?