How & why are fuses directional?!

So I’ve recently purchased a Synergistic research Pink 13A fuse for the Audioquest Hurricane cable that connects to my MusicWorks G3 Accuplex distribution block.

Before delivery I enquired with Audioquest about the directionality of the fuse in the mains plug as the live, earth & ground wires cannot be seen in the plug.

This is the image I’ve been sent and right away I realised I had my silver plated Bussman fuse installed the wrong way. So I corrected the orientation and fired everything up again.

Initially I got a flat sound as I expected after power down of the gear.

I’ve just sat down after a few hours of low level playback and the slightly hot/sharp treble I was getting from my setup has completely disappeared. I’ve often read that if the fuse is in the wrong direction, one will hear a less detailed sound but in my experience the sound will be uneasy. When corrected the sound will be more calm and composed. Yes I hear more detail but it’s sort of like the focus on a lens has been corrected.

So these are my findings, similarly to how I corrected the orientation of my NAC A5 speaker cables and had the same experience.

The puzzling thing for me is how can the tin fuse wire have directionality?! I wonder if fuse manufacturers such as Bussman are actually aware of this. I imagine they don’t care about fuses for audio purposes and therefore their staff are trained to put the fuse wire in any direction during manufacturing. After all the fuse will blow in any direction.


Looks like a fake Bussman in that picture. :thinking:

Unconscious bias does all of that.

The real truth is that of course fuses aren’t directional.


Ofcourse they are not directional.

If they were, they would only be directional 25 times a second, as its AC.


But signal cables are according to naim. What is the difference?

I’m pretty sure naim place the fuse in the same direction on all their power cables too.

The fakes always sound better :wink:

It’s a good question. We were told that Naim would listen to a sample piece of cable taken from a newly delivered cable drum, and decide which way sounds best. I bet no one is doing a listening test on Bussman fuses

Hi :slightly_smiling_face:

With that theoretical view,.you have definitely not listened practically.
I am inserting a text below about this that Fredrik Lejonklou wrote earlier.
Fuse directionality is probably one of the most laughable audio tweaks around. Most people shake their heads and dismiss you as a moron before they actually hear the difference themselves. I have no explanation for the effect other than that the sound difference it produces is very similar to what you get when you reverse the direction of a mains cable (power cord or a piece of cable inside a machine).

One reason why fuse directionality appears silly could be that it’s so small. People tend to think that since the piece of wire inside the fuse is so short, the possible directionality should be close to nonexistent. But the thing is that directionality, in my opinion, does not increase with the length of a wire. Reversing a short wire makes about as much difference as reversing a very long wire.
So take and test and evaluate this yourself,.I think you will be surprised.
I always do this when I install and optimize music-systems for others.

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Some people worship the fakes.
They love being ripped off. :rofl:

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I can’t answer the how or the why, but at Naim we certainly found a preference for the equipment fuses being oriented one way over the other. According to Jason Gould, “If the kite safety mark is embossed on the edge of the of the fuse’s conductive cap the fuse value should point towards the bottom of the fuse holder. Should the kite mark be embossed on the very end of the fuse’s cap then the fuse value should face the top of the fuse holder”.

However, note that this is relevant for Northern hemisphere. In listening tests that I did with Chris Murphy in both UK and NZ, we confirmed Naim’s preference when we listened in the UK but found we preferred the fuses in the opposite direction when in NZ. Weird but true and I have no explanation for it…


If speaker cable can be directional then, logically, I don’t see why fuses can’t. Either they both are or both aren’t, unless a fundamental difference between them that I’ve missed can be pointed out.

@Neilb1906’s point about AC is irrelevant, unless he’s also claiming that speaker cable - which also passes AC - isn’t directional either (and, therefore, that Naim are wrong to claim it is).

I can’t help noticing that those who claim X is directional usually cite as evidence their personal experience of it, express surprise and that they don’t claim to have an explanation. By contrast, those who deny directionality rarely cite personal experience and simply state it can’t be, also without explanation.



Synergistic research fuses are directional. How or why is another subject, but they are superb. Whether they’re superb for Naim equipment is also another subject.


I think there might be a reason why this thread is in the ‘Lounge’.


Fuses are usually shorter than loudspeaker cables, which I suppose you haven’t missed, but maybe forgotten.

What a great start of the weekend!


Well I guarantee that I won’t ever do this. There are so many actually interesting things to do instead.


Yep, i came to the same conclusion. As i was clipping my toenails listening to Sade, it never once came to mind that i might have a fuse in the wrong way round and have missed the magical musical moment.

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Did you do your left toe first?

You’re missing out pal. Try it and see. It would be a shame not to unlock the full potential of your system.

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What if turn it round and listen to Sade as you are clipping your toenails is it better?

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