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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.








jazzonthehudson
jazzonthehudson's avatar
jazzonthehudson OP
277 posts
 
UL in the US (VDE in Germany is a very well respected organization) have drawn up standards for low-voltage fuses (e.g. UL Standard 248-x). Besides adhering to low variance in expected values like breaking range, arc time & temperature, cut-off current, every part (body, fuse dial gauge, end caps, filling material,...) must lie within well-defined specs and even the process of fabrication is scrutinized. Those standards can be purchased from UL.
We're of course talking about UL certification which is a must for consumer goods, mostly done by independent labs who got their accreditation from UL.

For those who really know what they are into (and willing to take the risk), drilling into fuses is like riding a bike w/o hands, it can be fun but not recommended if you are prudent. Sometimes I like skydiving!

Bypassing fuses is not an unknown alternative and practiced by quite a few, even (small shop) manufacturers and I know at least two of them very well. Still, I like the presence of a great fuse, IME the SQ is better.
jea48
4,788 posts
 

Give me me one example, Mr. Smartypants.  Bet ya can't.
A  $100 bucks payable by PayPal? You game?
stevecham
3,340 posts
 
jazz, i like the way you increased the number of independent variables with brands of fuses in various places in your nad, in addition to the large number of orientations possible.

well done sir, well done!

in fact i'm beginning to believe
geoffkait's avatar
geoffkait
23,365 posts
 
Jea48 wrote,
Give me me one example, Mr. Smartypants. Bet ya can't.
A $100 bucks payable by PayPal? You game?

Just as I suspected.  You can't.

jazzonthehudson's avatar
jazzonthehudson OP
277 posts
 
Not sure how to comment on your last entry stevecham:
1. ) If I had not a limited budget, I would probably have selected something in the price range like SR Black. I have so I aim to increase the music listening experience in my HT, hence the emphasis on L+R.
BTW, in Home Theater setups, if you have noticed, people have different speakers and furthermore, if you have read up more on DIY, you would see people using different bypass caps for different drivers (in the same speaker).

2.) It is not uncommon that HT setups have one amp for the L, R, C and another for the surround channels.

This is an exercise to improve the sound in my second system, not one in statistics.
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