Swiss Digital Fuse Box, the fuse reinvented

Less resistance and resonance I would suspect.
When I had Magneplanars, one of the hot tweaks was to bypass the fuses for the elements.
The filament wire inside the fuse body along with the fuse body itself both resonate and the filament has a voltage drop across it.
I am watching the comments on this device closely.

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Hi, in Germany there is a company that pushes the topic of efuse even further:

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Interesting read.

Confirms my basic understanding of how and why the SDFB works….

Thanks for posting.

They should include some sort of sticker you place on the component with a warning explaining that this unit must be used with the SDFB. That way if anything ever happens to the original owner and the component gets sold down the road, the next person won’t burn his or her house down.


Wow good point!!!

I could not disagree more.

It’s simply a matter of replacing a Sluggo with a fuse if you want to take the SDFB out of the path of the current.

Does the equipment you buy used come with a sticker that says, “Please make sure the required fuse is installed before powering on”?

Personally, when I buy something that has a user accessible fuse, I make sure the fuse is in place before I turn it on.

I just don’t see the likely hood or extent of the hazard you are concerned about. Proper caution(s) are all that are required.

To each his own.


Sounds good in theory, but in reality how many people who buy used gear actually check all the fuses in their gear?

Update (now that I have sorted most of the SQ issues with the new Holo Red):

No issues with the SDFB, and no plans to return it.

Highly recommended.

One new observation:

I seem to have much better resolution of details at lower volume levels and can enjoy more music with the volume turned down.



FYI, I agreed to accept another SDFB specified for the PSA DS DAC (MK I) on a trial basis. It will be interesting to see if the observed effects are cumulatively beneficial.

As a reminder, the first one was installed in lieu of the fuse for my PSA P10 Regenerator.

More to come…

I’m interested in this product, but really curious how much difference the power cord that goes between the outlet and the Fuse Box makes.
Is it still a worth while upgrade over the stock fuse if say you use a mediocre grade power cord starting at the outlet? If not, I’d be more inclined to just use a premium fuse instead.

Good questions. Not sure of the answers, in practice…

I am trying to use the power cables I have already as much as practical to keep the value proposition as high as possible.

I would say this though – I believe the SDFB is addition by subtraction, at least in theory.

IOW, if the system sounds better without the “congestion” (for want of a better term or explanation) the fuse adds to the power supplied to a component, then the power cables would matter to the same extent (assuming they matter) they mattered when serving the system before the fuse was removed and the SDFB was inserted into the system.

FWIW, I have yet to hear a very material and consistent improvement with different power cables. My system seems to have benefited overall from the hodgepodge of used “better” power cables I have accumulated over the years but the SDFB proved to be different from a power cable switch, in that the (positive) impact on the presentation of the music in my system was immediately discernible and relatively significant.

The standard qualifiers apply (YMMV, IME, in my system, etc.)



Unfortunately I can hear significant differences with upgraded power cords, but I’m just not willing to spend a ton of money on them, would rather upgrade a component instead.
I’ve settled on the Synergistic Research Foundation line of power cables which are reasonably priced and made a significant improvement in my components.

That’s a curse, for sure.


The SR Foundation series appears to be really well received by users and reviewers alike.

Seems like an excellent choice.


It is amazing to me how many people there are in the audiophile world who have no understanding of electricity. Replacing a fuse with a breaker is an upgrade that was done in homes decades ago. (I have no comment other than SMH for the British). I especially like those who believe that if you do anything to a fuse including look at it cross-eyed, your amp will spontaneously combust. I am fine with ignorance; I just don’t like it when they smugly tell me [insert random wrong information here].

I’ve been asking for a breaker to replace fuses for a long time. What surprises me is that the swiss “fuse” doesn’t seem to have an amp rating. one size won’t replace all…theoretically. In reality, the input fuse on your amp generally does nothing. I accidentally left a sub hooked up during a test and blew the onboard amp in it a year or so ago. fuse did not blow. A friend put the wrong tube in a tube amp and a resistor immediately blew–this amp has 4 fuses, one input and 3 on the rectifier. NONE of them blew.

Fortunately, the fuses in your amp are NOT designed to keep your house from burning down. Amps do not spontaneously combust. Instead equipment damage happens. But we all spend thousands of dollars on equipment and if equipment is damaged, we replace it. Problem what problem?


That’s fightin’ talk around here!

We have a company fuse on the incomer (100 amps), individual breakers on each circuit, RCD or two across all of all or two halves of the circuits, a fuse in the plug, and usually one in the equipment too.

You guys run 110 volts (twice the fire risk), and have sockets in the bathroom next to the sink and bath. I rest my case yer honour!

See - fightin’ talk :smiley:

P.S. I’ve seen the results of bypassed fuses in amplifiers that throw a fault more than once.
Not pretty (luckily in the cases I’ve seen no one died).

These fuse replacing breakers actually seem like quite a good idea, but trusting software, and complex hardware, both with multiple failure modes, when I could just trust a fuse that cannot help but blow on over current, is a simple choice to me.

If you’ve never seen equipment caused house fires or injuries maybe it seems daft.
Me, I like to sleep at night :slight_smile:

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I wouldn’t expect a fuse to blow in that case - each individual component is not fused (that would be too much, even for us British :wink: ).

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Also note - I have not said anyone shouldn’t use this, but the risks need to be clearly stated too :slight_smile:
If the user is going to be around when it’s on, not really a problem.
If it’s going to be running 24/7 then additional protection would be wise (whether that’s a fuse elsewhere in the circuit or smoke alarms or whatever) :slight_smile:

@joma0711 So if a short circuit that blows a 10 watt resistor isn’t going to blow the fuse, what will?

As for the British protection system, I’m glad it makes you feel better and sorry for the negative impacts on your sound. You seem very passionate about it.


Depends on the circuit topology - a 10 watt resistor (dependent on circumstances) can easily blow/burn out on a lot less current than the fuses can stand, unless there was e.g. a appropriately sized fuse in series with that actual resistor (and that would be overkill).

Passionate? Well it seems you are correct, in all of my jobs it has, in one way or another, been part of it to figure out the possible failure modes, estimate the risk and impact, and mitigate those risks as appropriate.

Safety ain’t no detriment to my sound, man :slight_smile: