2. cables
  3. 124345-1776

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.








128x128jazzonthehudson
jea48
4,320 posts
 

atmasphere,

Again, great post. The best explanation I have heard to date for fuse directionality. I would think it should satisfy those that have experimented with fuse directionality and say they can hear a difference. I would think it should also satisfy those that say they did not hear any difference, when they reversed the direction of the fuse.

Three important parts for a good electrical connection:

Cleanliness. (Free from contaminants and or corrosion)

Contact surface area. 

Contact pressure.



Your explanation makes more sense, at least to me, that the directionality of the fuse has to do with a VD, voltage drop, across the fuse element itself. That assumes the VD across the fuse would be measured in millivolts.

 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....

 


geoffkait's avatar
geoffkait
23,365 posts
 
As it turns out the resistance measurements of the various fuses tested that appear in the data sheets on the HiFi Tuning website were done on the fuses only in both directions. Separate resistance measurements for the fuses in the fuse holder are also provided. Refer to page 2 of the data sheets for the resistance measurements in both directions. The interpretation of measurements is presented on page 3.

http://www.hifi-tuning.com/pdf/wlfr.eng.pdf





jazzonthehudson's avatar
jazzonthehudson OP
277 posts
 
With all due respect for the previous posters, I did reverse an (the same) Audio Magic Platinum in my PS Audio DSD (the same F1 fuse holder on the power supply board) several times and had other listeners present: we all experienced a consistent behavior (with the same tracks): that the direction influences a.o. the soundstage. As mentioned before, I always clean the contact points (fuse holder and fuse itself) before the tests.

To complement my tests, I would suggest, for the sake of experiments, to temporarily test with the same brand with a higher breaking current (e.g. 2A instead of 1A) to see if a lower resistance of the fuse would yield a better SQ.

I applaud those who bring in new technology or devices to enhance the SQ. E.g. the Lorentz force was known since 1865 but it took until recently to see the successful productizing of magnetic audio cables. Graphene’s discovery in 1962 took less time for audiophiles to enjoy it in affordable cable form (reference to a.o. Cerious Technology). I know for sure that one of the quoted examples that the designer -as I spoke to him on many occasions- did not go about scientifically but used his curiosity, his instinct and ears.

In this crazy and interesting hobby, I have learned to go away from my EE (Electric Engineer) trained brain to become more Experimental-oriented and Empirical.

Simply enjoy the music!

[SOAP BOX ON]
Listen to your system with your ears and an open mind, not an oscilloscope and if-I-can-not-measure-it-than-I-can-not-hear-it mind! Those who stated cables matter were almost put on a stake decades ago, look where we stand now (mind you, there are still some flat earthers out there),
[SOAP BOX OFF]

BTW, as a kindly reminder, there have not been as many practical inputs on how certain fuse sound and in which direction I had hoped for when I posted this thread, but then again, given the raised temper and wild directions (pun not intended) of discussions on the other fuse thread, I did not have a very high expectation.

PADIS (=Furutech?) fuses are on their way from Germany and I will hope to share my experience. My NAD M25 is still on the workbench (caps upgrade, did I mention that caps are directional in SQ?)


jea48
4,320 posts
 

jazzonthehudson said:

With all due respect for the previous posters, I did reverse an (the same) Audio Magic Platinum in my PS Audio DSD (the same F1 fuse holder on the power supply board) several times and had other listeners present: we all experienced a consistent behavior (with the same tracks): that the direction influences a.o. the soundstage. As mentioned before, I always clean the contact points (fuse holder and fuse itself) before the tests.

To complement my tests, I would suggest, for the sake of experiments, to temporarily test with the same brand with a higher breaking current (e.g. 2A instead of 1A) to see if a lower resistance of the fuse would yield a better SQ.

Anything is possible in this hobby. I do not doubt for a second that you as well as others could/can hear a difference.


Here is quote from an interview with John Curl.

quote:

"I was working with Noel Lee and a company
called Symmetry. We designed this crossover and I specified these one
microfarad Mylar caps. Noel kept saying he could ’hear the caps’ and I
thought he was crazy. Its performance was better than aluminum or
tantalum electrolytics, and I couldn’t measure anything wrong with my
Sound Technology distortion analyzer. So what was I to complain about?
Finally I stopped measuring and started listening, and I realized that
the capacitor did have a fundamental flaw. This is were the ear has it all
over test equipment. The test equipment is almost always brought on line
to actually measure problems the ear hears. So we’re always working in
reverse. If we do hear something and we can’t measure it then we try to
find ways to measure what we hear. In the end we invariably find a
measurement that matches what the ear hears and it becomes very
obvious to everybody."

http://www.parasound.com/pdfs/JCinterview.pdf

The why? It took time for Curl to find out the why. I just don’t think the why for the differences you and others are hearing is from a supposed difference in resistance of the internal fuse element inside the fuse. Especially when the fuse, as reported by other, is located on the mains supply side of the power transformer of the piece of audio equipment. Here we are talking about 120V or 240V depending on the country.

Post removed 
More to discover