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Direction of aftermarket fuses (only for believers!)

It is with reluctance that I start another thread on this topic with the ONLY GOAL for believers to share their experience about aftermarket fuses.
To others: you can call us snobs, emperors w/o clothes,... etc but I hope you refrain posting just your opinion here. If you did not hear any difference, great, maybe there isn’t.

The main driver for this new post is that I am starting a project to mod my NAD M25 7 ch amp for my home theater. It has 19 fuses (2 per channel, 4 on the power supply board, 1 main AC) and I will try a mix of AMR Gold, SR Black and Audio Magic Platinum (anyway that is the plan, I may try out some other brands/models). As it is reasonably difficult to change them, esp the ones on each channel module that requires complete disassembly, I would like to know what the direction is for these models mentioned and of course, others who HAVE HEARD there is a difference please share your experience on any fuse model you have tried.

Fuses are IME directional:
Isoclean is one of the first to indicate the direction (2008/2009) on their fuses. Users of HiFi Tuning (when the awareness rose quite a bit amongst audiophiles) have mostly heard the difference.

As an IEEE engineer, I was highly skeptical of cabling decades ago (I like the speaker design of John Dunlavy but he said on many occasions that cables nor footers matter at all, WRONG!). Luckily, my curiosity proved me wrong as well. I see the same skepticism that I and many others had about the need for aftermarket cables many, many years ago now on fuses and esp on the direction on fuses.

Another example is the direction of capacitors (I do not mean electrolytic types). Even some manufacturers now and certainly many in the past did not believe it can make a difference sonically. Maybe some do but it takes time in the assembly to sort and put them in the right direction/order (esp as some of the cap manufacturers still do not indicate "polarity") so that maybe is one argument why this is not universally implemented.








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almarg
9,670 posts
 
Jim, I believe that Ralph was saying that he has observed a 2 volt difference in line voltage, as received by the circuitry in one of his amplifiers, to result in a 40 watt difference in the amplifier’s power capability. Not that any of his measurements across fuseholders were ever that large. And as I read his post he was providing those numbers for the purpose of illustrating how sensitive the performance of some components can be to variations in the voltage they receive.

Note that that reference was immediately preceded by this quote from one of your posts:
Millivolts...... If that was the reason, wouldn’t the same reasoning hold true for the AC mains line voltage feeding the fuse? In other words a small VD in millivolts on the mains feeding a piece of equipment could/would have an impact on the SQ of the piece of equipment. Not hardly....
And his response began with:
You are correct in your first statement of this paragraph.
Also, I recall him mentioning the 2 volt 40 watt figures, or numbers that were very similar, in a thread a few years ago that involved voltage drops across power cords.

I of course agree with the rest of your post just above. I would also point out that the greater the amount of current drawn by a particular component, the greater the effects mentioned in your last paragraph will be, everything else being equal. And of course different components will have differing sensitivities to those effects, as Ralph stated.

Best regards,
-- Al

jea48
4,626 posts
 

Al,

Thanks for the clarification.

Jim

bdp24's avatar
bdp24
10,081 posts
 
I’d like to hear from AC power cord designers/manufacturers. Do any of them test the wire they make their cords with for directionality? They can't simply be reversed by the user though, of course.
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geoffkait's avatar
geoffkait
23,365 posts
 
bdp24
1,256 posts
06-01-2016 10:08am
"I’d like to hear from AC power cord designers/manufacturers. Do any of them test the wire they make their cords with for directionality? They can’t simply be reversed by the user though, of course."

And the answer is...

Not all cable manufacturers agree on the dodgy subject of directionality. Here’s what Audioquest says on the subject:

"DIRECTIONALITY: All audio cables are directional. The correct direction is determined by listening to every batch of metal conductors used in every AudioQuest audio cable. Arrows are clearly marked on the connectors to ensure superior sound quality. For best results have the arrow pointing in the direction of the flow of music. For example, NAS to Router, Router to Network Player."

Addendum: One would expect in this day and age and in light of the fact that most high end cable manufacturers employ cryogenic treatment routinely (as do some aftermarket fuse manufacturers) that high end cable manufacturers are aware of directionality and have taken appropriate steps to deal with it. Whether that's true or not would take some research. For power cords, while they are most likely directional like all cables, though they employ stranded conductors, directional arrows are not used since they aren’t necessary for power cords.

cheerios,

geoff kait
machina dynamica
advanced audio conceits

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