Swiss Digital Fuse Box - "What headroom sounds like"


Swiss Digital Fuse Box (SDFB) is non-sacrificial overcurrent protection device that serves as a replacement for fuses in audio equipment.

There are four devices in my sound system that I’ve replaced fuses with the SDFB, and its transformative capacity to upgrade sound quality beyond that of fuses has compelled me to write a review. I’m not associated with Verafi Audio, the company that sells them, nor did I receive anything from them as "review units". There’s another thread on Audiogon about them that an audiophile friend referred me to, which got me interested enough to buy them. I am now enamored with the sound of my system in its current state, so I wanted to share my take on one of the more significant steps in how I arrived here.

Before getting into details about its form and function, I want to share my impression of what the Swiss Digital Fuse Box (SDFB) does for sound quality. It makes my components sound like they are operating without any limitation of power. It sounds open and unrestricted across the audio frequency spectrum. The sound is dynamic, detailed, defined, and there a sense of harmony and completeness about it. It’s like my components can now output their full frequency and harmonic potential.

A few things about me... I’m more of an artist than anything. I’ve been a music lover for 35 years and an electric bass player for 15 of those years playing in two bands, with which I was the bass player on one full LP recording and one EP. I’ve recorded, mixed and mastered my own multi-layered solo bass recordings and their backing tracks from sampled percussion using digital audio workstation software. I’ve also fine-tuned two of my custom car audio systems using DSP software and built, tweaked, and tuned a high end home stereo system (yes I said *tuned*, without using DSP) . Given this experience and the resultant development of a keenly perceptive and informed "ear", yet having no formal electrical theory or engineering background, I feel comfortable suggesting that the results of using SDFB can be likened to how audio sounds when the device producing it is operating with ample headroom. What does headroom sound like? The term headroom has different meanings in its use within pro audio recording/engineering and electrical circuitry operation, but they are related in a way that the end result sounds uncompressed, undistorted, fully dynamic, and expresses the sense of the effortlessness of unrestricted flow.

Does this sound like embellishment? It probably does. And I haven’t even mentioned the typical audiophile terms like "inner detail", "layering", or "rock solid imaging", nor have I even mentioned soundstaging attributes yet -- even though all of these qualities have also gone through upgrades due to the SDFB’s being installed. Am I merely in an irrational, excited state because my whole system now sounds much more expensive than it is? I don’t think so. I’ve been using all four SDFB units for three weeks consistently, and the initial excitement phase I was experiencing settled at least a week ago. I also think that the more components a system has which have replaceable fuses, the greater the potential upgrade from replacing each of those fuses with SDFBs. Like I said, I replaced all fuses in four of my audio components (six fuses in total), and there were notable step-up improvements in sonics as I progressively installed each of them.

Now I’ll describe the physicality of the device and how to use it. Then, I’ll try to describe specifics about why my previous fuse setup, which was a combination of Synergistic Research Purple and Master fuses, was completely replaced by SDFBs. These SR fuses were already a major upgrade in sound relative to the stock, generic fuses, and the SDFBs transcended the SR fuses in every discernible way.

These things have two separate parts that work together: 1) a small box that is inserted as the middle of a chain created between an audio component and the electrical outlet from which it draws power, and 2) a solid, cylindrical metal slug (referred to as a "Sluggo") which is the same size as the typical fuse. To install a SDFB, first, with your component off, plug its power cable into the AC socket on one end of the box, and on the other end of the box there is a male IEC connector (C14) which you connect to an outlet using another power cable or an adapter. I’m using a combination of two short, homemade mini-cables, and two generic adapters with my four SDFBs for the best sound (details shared in my Audiogon virtual system). Once the box is connected to a live electrical line, it will go through a brief setup period, and after maybe 8-10 seconds, you’ll hear a clicking sound and the small green LED will stay lit, indicating that charge is now allowed to flow through the box. The second and final step, with the component still off, is to replace the fuse(s) with a Sluggo. The device comes with both copper and brass Sluggos. You can then turn the component on. Don’t replace a fuse with a Sluggo without the SDFB in place because you’ll have no overcurrent protection and you’ll incur the risk of severely damaging your component and/or having a catastrophic fire in the even of a short circuit or other overcurrent scenario.

These units monitor current magnetically, and are calibrated to whatever fuse rating is needed when you order them. They are also calibrated to operate as either slow blow, or fast blow, like a normal fuse. When the set parameters are exceeded (too much current), a relay is switched to the closed position and charge is halted from flowing. Being non-sacrificial, you don’t need to buy a new one, you just unplug it from the outlet for about 30 seconds and it will reset the state. Then it can be plugged back in and reused. There’s no damage done to the device due to the overcurrent condition, unlike a fuse which melts due to high heat. Currently, devices being produced are to be calibrated at 10 amps max, so if there is some crazy high current event, perhaps then it could be damaged. I don’t know. I believe that’s pretty unlikely though. I think I remember reading that there’s a 15 amp version in the works.

There is some inconvenience involved with transitioning to SDFB due to the extra weight of the box (not that heavy, really) and extra length added to the power chain, as well as potentially requiring additional investment in more power cables. I feel that I achieved an optimal result for only about $200 of additional investment by using some DYI cable materials I had available, some high quality plugs to terminate the cable with, and some cheapo adapters from Amazon. For me, dealing with the extra weight and length to the cabling and putting in the work to create the best solution for connecting the SDFBs to my power conditioners has not been a big deal compared to the profound jump in sound quality. Totally worth it.

Before I went all SDFBs, the best configuration I found with SR fuses in my system was one small Master fuse in the LPS that powers the modem and router (I have an all-digital streaming system), two small Master fuses in the DAC, one small Purple fuse in the preamplifier, and two large Purple fuses in the amplifier. It’s worth mentioning that total retail cost of this setup is about 33% more expensive than the retail cost of my final SDFB setup. However, if you choose to buy a bunch of new, expensive power cables to connect your SDFBs, that would quickly become more the more expensive option.

I thought the SR setup sounded great at the time. I was impressed with the top end detail that a few of the Master fuses added to the fuller midrange and mid-bass sound of the Purple fuses which I already had. I’ve seen comments from others on this site in agreement about this. This combination is getting some praise. However, when comparing that sound to the SDFB sound, it was like the SR fuses are stuck at a level of trying to boost certain frequency ranges to make up for how restrictive a fuse really essentially sounds.

How do you improve on a small, low resolution, blurry, drab looking photo? Well, you manipulate it in Photoshop, of course! You try to crank up values of various visual (light-based) metrics to make it more attractive. However, that process will never produce something as close to the original subject as when you start with an ultra-high resolution, high-dynamic range photograph. You can’t "add resolution" to something that is intrinsically underpinned to a state of reduced resolution. To me, this is analogous to the task of starting with the tiny, resistive piece of wire in a fuse and trying to add crystals and various substances of specific resonant frequencies inside and around it to end up with something representative of the innate completeness of the source material.

Comparatively speaking, I was surprised to switch back to the SR setup and find that the soundstage was compressed towards the center. It was like there was a somewhat spherical haziness in center stage from which the sound was straining to emanate from, even with the Master fuses in play. I attribute this sense of "haziness" to a combination of reduced dynamic range, and a distortion of the frequency response coming from the system’s components. If the hypothetical ideal response for a natural sound (assuming the important aspects of room acoustics and one’s hearing quality are held constant) is essentially a linear response from top to bottom in both amplitude and purity, then the sound of the SR setup was now perceived as distorted and a deviation from linearity.

The sound of the SDFB setup is far more natural, far more detailed, and imparts a sense of ease while listening. I’m using all copper Sluggos, as their tonality is more natural to me than the brass versions. The soundstage has opened up with more dimensionality and all of that perceived haziness and limitation of full expression is (seemingly) completely gone. Images became more defined and image positioning is on a more advanced level. I can now perceive the two singers positioned near center and side-by-side in the mix, with a gap of about about a head’s-width between their mouths. This wasn’t perceivable with the SR fuses. The positioning of cymbals on a well recorded drumset are precisely locateable in space. Listening to Russion choral music, I can now hear individual tenor and bass voices and their unique tonal qualities. On one excellent recording of a solo harp, there’s beautiful overtones resonating that I’ve never been able to hear before. The sound is descriptively harmonious.

Over the course of a couple weeks, the sound of these units opened up. To begin, there was some minor coloration of the sound, but I’m not sure I can hear it any more. I think most of it has gone away as the units have burned in. Even with the minor coloration in the beginning, the immediate leap above the SR fuses in sound quality was obvious and highly desirable.

One last thing, I did a rough test of the overcurrent protection functionality, as this is obviously a major thing to get right and have working properly. I’ve been told that most refrigerators pull about 1 amp of current, so I used that as a basis for testing since I don’t have any more sophisticated method (I could use my desktop computer PSU which has a wattage display to achieve more accurate testing, but I’d rather not have its power suddenly cut and risk problems). I have two SDFBs calibrated to trip at levels below 1 amp, and two units calibrated at significantly above 1 amp. With each of the two sub-1A units inline with the fridge’s power cable (doing two test rounds for each unit), they immediately tripped and the fridge’s power was disconnected when I plugged in the power chain into the outlet. For the above-1A units (also did two test rounds each), the units did not cut power, and the fridge turned on and operated normally. I feel like this testing demonstrates enough for me to have a boost in confidence in the overcurrent protection operational integrity.

Being able to safely use solid metal slugs in place of fuses is wholly a paradigm shift in a high end audio system’s sound quality potential. These things deserve attention and I’m grateful to have been pointed to them.


https://verafiaudiollc.com

128x128gladmo

Thank you, Gladmo for bringing this to our attention.

And for cluing me in to a 'weak link' aspect I had not encountered yet, fuses.

The Swiss Digital Fuse Box is now on my list - for components.

I wonder what people recommend for speaker fuses.

 

This has been one of funniest threads I have ever read! I can’t believe that that Rick guy is still making contact liquid. It’s so sad it’s funny. 

Good Morning 

@pinwa 

@thecarpathian 

Please do not try "just slugs"

May I please ask you both contact me via email and let me loan you a SDFB.

I cannot afford to put a fleet of these out there - but a few in rotation I can muster up for.

Thanks - Mark 

Yes, but if you're doing it strictly as a temporary test to see if you hear a difference while staying vigilant of the potential dangers, I think it would be a good indicator of efficacy.

@pinwa - replacing a fuse with solid copper not only runs the risk of damaging equipment, it will also invalidate your house insurance if, for example, a lightning strike were to cause a fire. And those things do happen.

I understand the important role of the Swiss Digital Fuse Box in terms of protecting the equipment but if one simply wanted to test for any sonic improvement is there any reason not to simply replace the fuse with a 5x20mm copper rod?  Obviously this risks destroying the equipment, but would the sonic effects be the same as the SDFB and Sluggo?

Whether it's new and improved slugs or next level Fuse Boxes, I'm excited for both. Only improvements to come from this point on.

Post removed 

recklesskelly,

Yes, everything matters. (sometimes). Its only as good as the weakest link...

Rick from the High-Fidelity Cable era is still making a product called "Pro" which he claims is far superior to his previous QT 45 or NPS 1260 signal enhancer gel. I think the claim is it increases conductivity and seals outside RF/EMI interference.

ozzy

@ozzy Very interesting tweaking a tweak? Also what is this "Ricks Pro enhancer"?

I changed the IEC in the Fuse Box to a Furutech NCF version. The blades are much thicker. Fairly easy to do.

I also made my own AC jumper(s) cable out of Furutech cable with Furutech NCF AC/IEC fittings. All internal wiring/connections was treated with Ricks Pro enhancer.

And of course, I am still experimenting with the solid .9999 silver slugs.

The only thing I couldn’t upgrade was the AC plug inlet.

ozzy

@yoby 

 

You are so right. I will get some help and get this done soon.

My web site isn't so spectacular either - just learning how to do this kind of stuff :)

Thanks - Mark 

@verafiaudio: Hi Mark: An instructional You Tube video would be very helpful in showing the different ways of setting these up. Goof listing. Jeff

@vandy357 

Good Morning - YES, everything from Vera-Fi comes with a full 30 day No Questions Asked Money Back Guarantee. None requested for this product. 

I have given extensions of that Guarantee for guys that needed more time for assorted reasons. 

@lalitk 

Thanks. I know of one good guy working on some super ideas for thew SDFB. I'm open to suggestions and improvements. 

Best to all - Mark 

Mark @verafiaudio 

Great post!  Speaking of improvements, I hope next revision of SDFB eliminates the need for pigtail PC or inexpensive male to female plug @thyname suggested. 

I just find it quite amazing that someone other than me can tell me what I hear or don't hear.  I have a suggestion, before you disparage a product why not give it a try, what do you have to loose, as far as I know Mark gives a money back guarantee (correct me if I am wrong Mark).  Look, I was very skeptical before I tried one of these, but changed my mind completely after listening to what it did for my humble system.  Don't knock till you have tried it! 

Good Evening
 

I’m of the “no magic” clan when it comes to Audio in general. Products must stand on their own 2 feet and make improvements with Science as the Spine

I remember very well people thinking that Peter Madnick and I were out of minds making “digital interface boxes” in 1990/91. The DTI (Digital Transmission Interface) became a runaway success story with more than 6200 of these little guys sold with the notion that Jitter was bad for “Digital Audio”. There were no shortages of Disbelievers. I remember it well…

 

Only we were right, and Doug Goldberg and Peter Madnick made something incredible that stood the test of time.  I remember calls from some pretty serious Industry People just praising the heck out of that product


Forward many years later and people said Class D is poopy garbage. It’s not, and the Warp 1 from Dr. Viet Nguyen (and me) continues to confound the experts with it’s amazing sound and unbelievable value quotient

. Take a read on Tom Fine’s (a serious Audio Expert) report for the July Stereophile.

Class D is bad…….. only it’s not.


Just before this Dr. Skip Taylor ( a REAL Audio Legend) came to me and told the story of why GaN amps are better (On Switch Condition etc .etc.). I believe in the man I’ve known for over 35 years and made a GaN amp for Walter at LSA and that amp may well be the best amplifier I have ever heard.

 

Just look at what Peachtree and Java HiFi are doing and ask yourself why people disparage GaN and the like.

GaN rules and you will see more evidence of this soon…

Jon Iverson EK-1 – Electret Based Phono Cartridges are CRAP --- I worked for this man many years…

Only this was the very best phono based system I have ever laid my ears on.


I can go on and on. Arnie Nudel (my Mentor) with Servo-bases subs etc. etc. Expensive and impossible to make sound right….

Only they WORK GREAT and Tactile Bass Response was born.  Infinity started this (Cerwin Vega up the block) and at Genesis we made some pretty killer woofers.


Why am I saying this – simple


That little metal fuse which has been assaulted by some GREAT Companies and people (like Quantum Science and Synergistic Research) that are making something better for something that clearly is not the end all be all…


Swiss Digital has done the same with serious Engineers at the helm and with equally serious companies using and enjoying our product improvement. ARC comes to mind (they have 8 of our little friends) and there are a host of others.

 

SDFB is here to stay. Safe and a REAL Improvement to the normal thinking that pervades audio. There are good people working on improvements to SDFB and for sure you will see some of this soon.


So – I’m not sure if this makes ME A High End Guy – but here I am at almost 4 in the morning wanting simply to say --- there is more and better coming. Of this I am sure. For now, the Swiss Digital FUSE BOX is here to have it’s voice heard. And, it clearly is.  


 

I predict that this brevity free "digital fusebox" laden with hyperbole is another remedy for something that isn't a problem...regular little fuses supplied with gear. Like the ever more expensive SR fuses that have had endless testimony here praising the efficacy of a half inch of wire that's been somehow exposed to magic, this will never catch on with high end audio fans or gear designers to any serious degree. My prediction could be wrong...send an SDFB to Nelson Pass or Dennis Had and see what they say about it...I bet a response from one of them will take up far less space than my prediction. 

I found a new use for the system. I install the Sluggo’s right in my main electrical panel. It works great. I’ve been saving money on my lighting bill for the house. It especially works good when I lather it up with that contact enhancer from that, Rick Schultz guy. He’s such an honest guy. I’ve got so many magnets in my system. It’s running like that CERN place in Europe. . it’s so smooth. It’s like a recto linear rear endoscope. The music just flows out. It’s amazing. Anyways, I’m gonna try this new Swiss fuse system in the 220 V section and see if I can save some money on my air conditioning. Wish me luck

@lalitk : 😂🤷‍♂️. It is what it is. Fuse rails inside would be fine (and untouched) if there was one main power fuse at AC input. Which there is none for Esoteric N-01XD. Having said this, the utility of the Swiss Fuse Box is simple: if one is, or was, able to replace fuses with any of the third party “audiophile “ fuses before (such as those from Synergistic Research), the Swiss Fuse Box will work.

@thyname 

SDFB heard your cry for help and they have gone back to LAB to design a custom multi-fuse box for Esoteric DAC. I know I could use one for my Marantz SACD player which uses 8 fuses 😎

@thecarpathian : if you have an equipment with no "MAIN" fuse (the power fuse that Mark mentioned above I believe), then I don’t think you can do this. For example, I inquired with Esoteric for my DAC (the N-01XD), and I was told this:

---------------

There is no “main” fuse for the N-01XD, but rather 4 separate banks of fuses. 1 bank for each of the left and right analog power PCBA, digital power PCBA, and network power PCBA; a total of 15 in all.

--------------

Which means that I am unable to implement the Swiss Fuse Box for that DAC. Or at least I don’t think I can.

Good Morning

@thecarpathian 

You can replace the POWER FUSE with our Sluggos 

When you say "every fuse in the component" am I to assume that you have a Tube Amp with Fused Power and B+ lines?

If so - just the Power Fuse please

The rest you have correct - Wall to SDFB  - SDFB to your gear 

Super Simple 

Good Instructions On Line too

Here to help in any way

Best wishes - Mark

@verafiaudio ​​​​​@thyname ,

Thank you.

Now, just to get this through my thick noggin:

You place the the fuse box from an outlet in line with a components power cord, and you can use the Sluggos to replace every fuse in the component? 

 

Good Evening 
@thecarpathian 

I have Solid High Purity Copper with a Gold Immersion 

As well - Solid Brass with the same Gold Immersion 

25 dollars each shipped. The results are truly head-turning and a tad mind blowing :) 

@thyname 

Very much appreciated - enjoying this more than ever because of the good people like you and others. 

Best wishes - Mark 

I can answer that as I just ordered two (one each): Solid Brass with the “Gold Immersion”, whatever that is, and silver. Cost for each is very reasonable, peanuts in the grand scheme of things. We’ll see… 

 

I have to say, Mark is a true gentleman, in the real meaning of a human being (forget about the business part), and a pleasure to deal with

Good Afternoon

Not sure how to do this without getting in trouble. 

The Tier 1 Upgraded Sluggos arrived today (at last). 

These were tested in several systems and proved to be a very real upgrade. 

This is a very low-cost solution --- taking the SDFB to the next level. 

Feel free to e-mail for more information. 

I'm not going to post my e-mail - but it's been posted elsewhere, so it should be easy to find me 

Thanks - Mark 


 

Update:

I still have the Silver slugs in my amps. Since I am only playing them maybe 4 hours a day it has probably been less than 50 hours total playing time thus far. I’m going to wait until I get closer to 100 hours before moving back to the copper slug.

But at this point, I am very satisfied in the sound quality. The sharpness first exhibited has completely gone away.

ozzy

klh007

Yes, the copper sluggo replaced the SR Purple fuse in the amp fuse holder. And is inline with the SDFB.

Good Morning 

@klh007 

One SDFB only at this stage - @tubes21 was ready to only go THAT far (at this point?)

He used the SDFB with his very nice amp, The Mac 275 v5 

I think more are in @tubes21 future, but grateful he went outside of his comfort zone to try our product. 

I hope others will post - but sure delighted to read this. 

Best to all - Mark

@tubes21 I completely understand how the SDFB works, are you saying the sluggo is in your power amp and the SDFB is inline with it?

The one fuse box, short pigtail power cable, and one sluggo are not ‘in’ a component. One end of the fuse box connects to the wall outlet via a short cable. The other IEC end connects to the amp via your existing cable. 

That is the basic configuration of maybe 98% of the Agoners who have commented on the SDFB aka fuse box. No other components are involved or desired in their systems, while the other 2% systems are easier to diagram than write about.

For more information please contact Mark Schifter at Verafi Audio. He will respond promptly. Thanks -

@tubes21 : I think @klh007 knows how the Swiss Fuse Box works. He was asking (I think) how many components you are you using a Swiss Fuse Box on. In other words, how many fuse boxes you have and each used on what?

 

Good questions - Yes and no. 

Yes, my comments are based on what I heard after trying out the fuse box in my existing configuration of Equi Core, Deep Core and Puron power conditioners. Pass and Seymour cryoed hospital duplex (Take Five Audio). 20 amp dedicated line. 8 ft ground rod. The before was asking myself if the fuse box is another over hyped new product.

No, in this configuration one fuse box and one copper sluggo. For the details Mark at Verafi Audio is the go to dealer. https://verafiaudiollc.com/

@tubes21 How about telling us how you used the SDFB, in a single component, or as the fuse in your EquiCore with all components plugged into it and all components having sluggos in them?

Thanks for the kind words. If I understand your question correctly, the single fuse box cable is plugged into the wall outlet, and your power cable is plugged into the fuse box. The ‘fuse’ per se is a solid copper or brass rod (Sluggo) that replaces the amplifier fuse and goes into the amp’s fuse holder. 

This is one configuration for adding a fuse box to your system. Another configuration connects the single fuse box to an Equi Core power conditioner for optimizing the jaw dropping energy and dynamics of live music. If you don’t want to stop there, a third and fourth configuration optimizes clarity and imaging by adding a Deep Core and Puron conditioner. For more details Mark at Verafi Audio is the go to man.

@tubes21 Thanks for sharing your experience with the SDFB, what component did you put the fuse in to achieve your stunning results? Was it only a single SDFB?

I’ve learned a lot from the Agoners’ feedback with the Swiss Digital Fuse Box.

My experience started with calling Mark at Verafi Audio and then talking for half an hour as we surveyed the 40 year history of home music vs state of the art vs live music.

Mark graciously broke in the Core 12" power cable and SDFB for 50 hours. And he was good also with a 30 day trial period, if I needed it, because a brand new power cable frequently can sound bad, flat, dull on arrival.

So, when the cable and SDFB arrived, Mark had dealt my concerns with trying to evaluate brand new power cables.

Still, however, I must have been basically expecting one more new product and an incremental upgrade of my system. I did not expect that I could be transported to the real sound of live music - that came out of the blue - especially with my system, my room and my ears.

Previously I had not ever ‘heard’ the authentic sound of live music anywhere, anytime even on the $60,000 - $100,000 systems of high end dealers. Their systems had state of the art gear, excellent listening rooms and incredible recorded music.

But they did not sound like a live performance with nothing between me and the music. Nothing like a Row H seat in a concert hall and nothing between you and the orchestra. Nothing like sitting up close to a singer and her band.

The SDFB ‘sound quality’ was so unexpected, breathtaking ...and realistic. The silence is stunning. The energy palpable. The definition, soundstage, bass, attack, slam, treble extension are all energized, alive, natural and musical.

Albums and streams are heard like You Are There at the original, non-electronic, immersive performance. Nothing between you and live music. You Are There.

My system: Macintosh 275 v5 tube amp, Auralic Altair G2.1 DAC/streamer,  Fyne F502 floor speaker, MacMini with OSX Ventura and six Audio Sensibility PC000X 6N cyroed cables. Power components include Kimber Kable Palladian power cable. SDFB with short Core Cable, Core Equis 1000, Deep Core 1000, and Puron power conditioners.

@vandy357 

I appreciate very much you're adding these thoughts to the thread here. Thank You

It's been a really great 5 or 6 days with positive comments as well as suggestions and great future ideas - I believe tomorrow or Saturday I will be in a position to share some new (great) news

Thanks - Mark 



 

I just added a second fuse box to my system, hooked up to my DAC. The improvement to the soundstage is quite amazing, now the musicians seem to occupy their own spot on the stage. On my first listen I was thinking wow I have never heard that song quite like that before. When I added the first one to my amp it made a difference for the better in the overall sound quality from top to bottom plus made some improvement to the soundstage, this one maybe added just a smidge to the overall sound, but the difference in the soundstage is impressive. I am loving what these things do for the sound of my system. If you decide to give this a try, rest assured that Mark is a great guy to deal with, so accommodating and helpful, it is nice to know there are people like him in this hobby of ours…….Bill