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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
geoffkait's avatar
geoffkait
14,147 posts
 
Charlesdad wrote,

"Geoff,
I didn’t intend to imply that the SR fuse lettering suggested current flow, rather that this is the orientation providing the best sound quality consistently in my components.
Charles,"

Hi, Charles, can I respectfully suggest you re-read what I wrote? Also re-read what Ted from SR wrote. There appears to be no consistency from fuse to fuse regarding lettering or indication of direction. So you can't go by the lettering without trying both ways.

cheers,
geoff at MD

almarg's avatar
almarg
8,673 posts
 
JazzontheHudson, while you're probably already aware of this you can download a pdf of the service manual for the M25 via the following link, if you first complete a simple registration process at hifiengine.com:

http://www.hifiengine.com/manual_library/nad/m25.shtml

In addition to the schematic you mentioned having, the manual includes printed circuit board layout diagrams and other information that might be helpful.

Thanks very much, btw, to you and Charles for the nice words.

Good luck as you proceed.  Best regards,
-- Al
 
mapman's avatar
mapman
15,679 posts
 
Geoff, as I read it the Op would appreciate your help if not mine which is fine. Don’t just check out because of me. :^)
jazzonthehudson's avatar
jazzonthehudson OP
277 posts
 
Thanks mapman and GK!

Al, thanks for the info, I got most of the manuals there at hifiengine and in this case, got the service manual directly from a good source at NAD. I try to have service manuals / schematics of most of my gear, primarily to understand where they come from design wise. Most tech departments understand why I wanted it and provide the info easily. If the manufacturer remains stubborn, sites like DIYaudio and others may shed a light. 

A side question: I enjoy the zapped products from SR: fuses, wall sockets (though Furutech GTX- D(r) remain my reference, havent tried the new NCF version) , etc. Have you experimented with superhigh voltage to create that tunneling effect in cables?

For others that feel "attracted": I have been using HFC cables for many years with pretty good results. I have stalled in my quest to create my own magnet cable (just for fun) as I can't find a suitable ready-made conductor cable, would be helpful for any practical hints.

*also a* Charles


mapman's avatar
mapman
15,679 posts
 
You are welcome. Good luck.

" Lesson learned, early adopters (we should have been over that for fuses but obviously we’re not) pay the price/scrutiny. "

That is very true. They don’t call it the "bleeding edge" for nothing. :^)  Not for the faint of heart.....
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