Hi all, if any of you have HIFI TUNING FUSE with P10 or P5, may you share the arrow pointing into machine or toward the fuse holder cap, which comes with better sound?


I too would like to know the direction people are finding better.

My new Hifi tuning fuse I put pointing into the machine. I am breaking in some other equipment, so will be a while before I try changing directions as my sound now seems to be a little uneven during the days/night.

May ps audio team let me know which is the correct electric flow? Blue arrow or pink one?

PS’It’s not hifi tuning fuse in the photo, it just was the fuse I fed the P5 I ever had previously, the photo is just for discussion.


The best advice is to try the fuse in your intended piece of kit and determine your preference.


Yes I know and actually that’s what I’m doing now.

I can judge by my ear, but still would like to know the electric flow and hear the experience from other guys.

Thanks for your advise.

Elk said The best advice is to try the fuse in your intended piece of kit and determine your preference.

And what have you concluded sounds best?

d8953903 said May ps audio team let me know which is the correct electric flow?
In principle the fuse is placed where the current and voltage are alternating so the direction of the fuse shouldn't matter. Without a clear explanation of how the fuse works from the fuse manufacturer there's no way to tell you the "correct" direction of the fuse.

For that matter I don’t know that the manufacturer keeps track of the fuse’s “direction” before they label it.

Also I’m not convinced that the mechanism isn’t somewhat system specific anyway (perhaps it’s dealing with low frequencies differently than high frequencies.)

Without more information from the fuse manufacturer it’s purely a personal preference. If you can’t tell which way you like it, then does it matter?


Currently pointing into machine sounds better to me, shape is better, bass frequency energy is stronger, sounded wider and more natural.

Hi Ted

Thanks for your comment, I agree with you opinion. Maybe it depends more on personal preference.

Actually HIFI TUNING told their user that pointing arrow can be a reference for installation even after a lot of people test, it seems not always so.

I’m still looking forward the answer of electric flow direction from ps audio team. It’s only a reference, not meaning I will just wait & follow. I trust my ear more. ^^!

d8953903 said I'm still looking forward the answer of electric flow direction from ps audio team.
I did answer: the fuse is in the AC side of the circuit where the current flows both ways equally.

Hi Ted

Thank you for your reply~

BTW I tried FURUTECH fuse and Hifi tuning fuse these days, always I got different sound with different installation direction.

It’s interesting. Originally I thought the difference might relate to fuse wire characteristic (one way with more resistance, like RCA cable).

maybe better sound results from the match between fuse direction&current flow.

But if current flows both ways equally(neither Blue arrow nor pink arrow in the photo above), I can not figure out how the difference comes from~

Just curious.

Anyway, thank for your reply again.

PS’ I’m not really good in English, sorry for my poor expression.

I can think of multiple ways they could work. But truth be told I don’t really care enough to run some experiments to find out1_gif

Ted, if you would be so kind, I would be interested in a listing of possible ways fuses could be directional, fully understanding this fully hypothetical. It makes no sense to me how a piece of wire in an A/C circuit could be directional without acting as a rectifier.

But the mere fact I do not understand does not mean it cannot be true. laugh

Well first off there has to be something asymmetrical about them. Also non-linear behavior is a given given their function.

If we model them as a perfect diode in parallel to a non-linear resistor, then having a little less conductivity in one direction must have a positive effect. Then there’s the possibility that they are only asymmetrical at some frequencies and not others, e.g. they may limit the high frequency kick back when the power supply’s diodes switch.

Anyway with a half wave rectifier power supply the chances for interactions seem clearer: e.g. flipping the fuse may limit current spikes differently.

Another approach is to look at, say a world where the noise we are interested in is a positive impulse. If the noise is from the outside obviously a asymmetrical fuse could keep it out or let it in. Similarly if the noise is from the inside…

I just balk when the manufacturer talks about which way the current flows: which current? With a full wave rectifier or other symmetrical power supply topologies that doesn’t give any explanation or guidance at all.

Even with a symmetrical power supply topology it seems like there’s both the possibilities of uneven current draw from the device that’s correlated with the line voltage or conversely that other half wave power supplies in the rest of the system have flattened the top of the AC waveform more than the bottom… These all leave room for an asymmetrical device to make a different difference depending on polarity.

The only thing I can think of is that removing and reinserting the fuse might clean off a bit of oxidation and improve signal flow. I wouldn’t think the effect would be big enough to notice, though. And if that’s the reason, removing and reinserting in the same direction should have the same affect as removing and reversing the direction. The fact that I can’t think of anything else just shows my personal limitations, of course.

Thanks, Ted. Fun to mull over.

But if the fuses are truly directional I would expect the manufacturers to carefully mark this and to make a point of it. I don’t recall anyone cutting one of the specialty fuses apart. My bet is they have a single piece of wire in them, just like any other fuse, but better quality materials with improved contact with the end caps. They are just expensive enough I cannot get myself to buy one just to tear it apart.

Cleaning contacts of interconnects and speakers cables and power cords, even just by unplugging and plugging, seems to improve the sound. This certainly could apply to fuses as well.

I think what could be learned here is that Ted did not say that turning the fuse is utterly bs, so I guess this tell something about most of us staying open for perceived experiences, still if it defy our fact-based belief.

It is always worth keeping an open mind; audio is all about subjective experience.

And even if there is no physical actual difference it does not matter. A placebo effect that pleases you is just as real. I do not mean this disparagingly. If your comfy robe makes your system sound better to you, wear it. smile

I use HiFi Tuning Supreme fuses with my P10s and my P5. The best sound in each case was with the fuse arrow pointing toward the rear of the P10/P5.

HiFi Tuning says generally, the best sound will result when the arrow points away from the end in which current enters the fuse holder. For the P5 and P10, the current enters at the rear (cap) of the fuse holder, but there was greater clarity of sound and more space between instruments with the fuse arrow pointed toward the rear of the fuse holder.

GECOM did a study on HiFi Tuning and some other audio grade fuses, as well as ordinary fuses, in January of 2010. There were minor to significant differences in resistance depending on fuse direction.

GECOM Fuse Tests January 2010

I checked my P5 with a multi meter and the direction of the circuit seems to be like this on my P5.

Not that it might matter but buzzing one leg on the 3pin input power on the back and to the fuse holder.

I can’t get behind my P5 while in the rack, so not 100% sure.