Fuse direction in K50

Fuse value is small 1A slow?

What direction does the current flow when removing the tray?

The fuses we use are as below…

0001.2508 Shurter Fuses


Hold the red connector the way you would in order to insert it into the receptacle.

On the right side the direction is from the back to the front. On the left side the direction is from the front to the back. This is true whether 115v or 230v. But in some countries you are wise to also try reversing the polarity of the power cord (EU for example and that is easy to do with a Schuko) because of how they separate the phases of their power delivery.


Is it the same for the K40?

Yes indeed, the same

If any of you find the ideal orientation for your fuses, please report back here.

I have oriented both of my blue fuses in the same direction, but according to the above, one of them needs to be flipped.

If the fuse is on the AC (alternating current) line then the current and voltage potential changes direction 50 or 60 times a second. The way a fuse is inserted should have no effect.

That’s only true if the fuse is beneficial because it’s effecting the flow of current. If the benefits are instead related to addressing how noise enters the component, then directionality not only matters, it might be essential to get it right to achieve optimum benefit.

Synergistic’s UEF material aims to clean up high frequency noise. There are particles in that stiff that get excited by EM fields and (I think) turn that energy into heat. The benefits we hear from fuses largely come from that.

I think many have misconceptions about how energy actually flows. This is a cool video I encourage everyone to see:


Not sure about the fairy dust but as long as they are UL (not UR) or CSA approved or other local authority, why not.

Video was interesting.

I learned about much of what was presented in that video over 30 years ago when I attended engineering school. I’m less inclined to refer to Synergistic’s material as ferry dust because of what I learned back then. I think it’s s really innovative approach to addressing noise reduction that Synergistic is pursuing.

Shunyata also exploits materials to reduce noise. In their case they use a ferroelectric material. By doing so they are able to reduce noise without harming dynamics the way traditional filters do.

I think my most important lesson from my time in the engineering world was to be humble because we can’t know what we don’t know. Most engineers don’t get that. They think being an expert in one area makes them an expert in most. It was seeing how stupid their hubris made them that encouraged me to always try to be humble.

I think I know what the UEF stuff might be doing but whether or not I understand it won’t determine whether I will try their products. I recently tried some of their brand new Carbon Tuning Discs. These were fun to play with and they also delivered a good bang for the buck when optimally placed. A few places I tried them they actually harmed the sound.

I just recalled another learning from back in the day. Senior year I took a materials engineering course. We looked at grain in metals and their impact on conductivity. Fast forward 15 or so years later and I learn of OCC “single crystal” wire. All the smartest people told me that this is “snake oil” and that it couldn’t possibly matter. But I knew that there were sound engineering reasons why these conductors are a great choice for audio. It doesn’t surprise me at all that many audiophile cable manufacturers are using this stuff in their products these days. It’s just unfortunate that some are too smart to appreciate the benefits themselves.


As I said, as long as they have been approved for use as a fuse by UL, CSA so that one can be sure of providing their actual function, use them. The rest is a manufacturer’s claim that can only be certified by the ears of the listener.


That’s the way I inserted the new fuses in my K30


Does anyone know the right polarity for both EX and CX? I don’t want to open the boxes but would like to know the position of the phase pins of both. Please describe this with the right point of view (seen from back or front).

Apologies for this, but ‘back’ then means the aspect of the fuse holder that is flush with the rear of the K50, and ‘front’ is the aspect that is inserted into the K50?

And would other devices that have a similar fuse holder e.g. Mutec Ref 120 be likely to have the same current flow?

(5) CX, EX, K, S, Antipodes, Owners Unite | Page 18 | Headphone Reviews and Discussion - Head-Fi.org

Flip the fuses, I found the direction by accident, as it sounded best to me although I could not work out the direction of flow, later to my surprise Mark confirm the direction.
PS I know electric does not flow but in in simple terms A to B to explain the fuse direction if that makes sense ?

Looking at the rear of the unit, on the right side using an SR Purple fuse
the “S” points to the rear.
On the left side the “S” points to the unit.



Just for those who don’t know, read sbout QSA fuses.

BTW I have a lot if Synergistic Research stuff, it works very well.

As the saying goes, if you need to ask how much they are then you can’t afford them. :rofl:

As I understand, the low cost QSA fuses perform better than the higher cost Synergistic Research. But if you really wanna burn some money, you can do that with QSA too.


The SR purple runs with the QSA violet

The QSA Red is the fuse to get!

So in your opinion, SR Purple (US$200) is equivalent to QSA Violet (US$711)?