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

Showing 35 responses by verafiaudio

@yoby 

Thanks so much - we have High Purity Copper with Gold Immersion Sluggos in stock now.

Brass the same way too

More Sluggos for next year plus 3 x new DC Snubbers with some very cool tech 

Many thanks

Mark 

@vandy357 

 

Welcome to phone me on my mobile phone - 303.594.7586

 

Happy to help anyone that needs any questions answered.

Thanks - Mark 

As posted elsewhere - thank you guys 

 

Greetings 

Happy Holidays 

Thanks to all of you guys for sending people to us for the BF Deal 

Appreciate it 

We have 8 units left and then no more until mid December as we are waiting chassis from Japan

Thanks again - Mark 

Forgot

Thanks for your e-mail JCA – our 30 days No Questions Asked Guarantee is in place for this product just as we offer for Puron etc.


 

Good Morning

@gladmo

Thanks for the wonderful review. I think you’ve said it in fine fashion.

SDFB is catching on quickly, but there hasn’t been a lot written really except by a few others. I am really happy reading this again this morning.

I sent this to several friends last night after it was published. Lots of feedback this morning.

I’ll do my best to stay out of this and answer only when necessary


@thyname

No need to worry – very safe
😊

Many of you have my phone number – call or text is fine – email too



 

@tksteingraber

Works everywhere, but on my two rigs amps made a game changing experience happen


@gnu

I shared this with Walter last night.

Most of you know that I lead the Underwood DEV TEAM (going on 11 years) re LSA, CORE POWER and EMERALD PHYSICS – lots of new products shipping this month and next for The Wally…

The new Bob Carver products as well for Jim and Bob

Wally has his way of doing things. He’s pretty dang good at it
😊


@audioman58

You are spot on.  I leave the B+ rail fuses alone and head for the Power Side of the Fuse requirement.

New Sluggos are in-bound (FINALLY) now from my supplier in China – but we also have some very special ones being made in New England by my buddy Dana B with C101 Copper – SUPER HIGH PURITY – 99.99% PURE COPPER that has 0.0005% oxygen content.

As well, thanks to groovy sauce over at Decware forums I’m bring in some Super Coated Plated Sluggos with Rhodium Plating etc.

And yes, polishing too.

Now that the new Carver Amp is in production, I can get back to listening more – this is pure enjoyment for this old man.


Thanks – Mark

 

@gladmo

In between lunch and a business meeting but I can share this -

The default condition for the relay is OPEN, so if there is any failure no current can flow to the attached device.

 

@cleeds

That’s kind of a Wally-thing. I long ago let this go and I just don’t enjoy arguing it out with him or others that copy Reviews for their web sites or Promo Materials.

Thanks - Mark

 

@gladmo 

PS - when the new Sluggos arrive from various sources I will gladly let you (or others) test... 

@tweak1

 

Today I received (finally) the first of the next gen of Sluggos. I love the name Slug Club

Trying coatings, polishing and exotic materials.

 

Thanks – Mark


@thyname


 

So glad to read this. I’ve had one of those amazing days. Just incredibly glad for you and the others that have stepped up

Very nice fellow in the 901 that tried a SDFB for this BHK 250. His results make me so happy for him – and my guys in Switzerland that made this all possible for us. The note was incredible. More of this daily now.

 

@gladmo

Register that name. 😊

I love it

Best to all – Mark

 

Just logged in to read all of this. 

Opinions are fine with me - just NOT conclusions without examination

I have offered @recklesskelly a FUSE BOX for himself. 

We have good Science and a TON of testing 

Will wait for a reply. 

Thanks - Mark 

@recklesskelly 

 

No Validation being sought for any of the Certificates as discussed

I appreciate your willingness to participate 

My sincere thanks

Mark 

@pinwa

Thank you for your question

We require direct feedback with this end user at this time. We make absolutely sure that we are programming your SDFB to precisely what is required. In many cases, we even double check with the manufacturer. 

Once we have the data... we program, burn in and then ship. 

@thyname 

We are in process right now with developing new and more "advanced" Sluggos. 

This includes materials - and "treatments" . Some pretty exotic variants are coming.. Tremendous help by several of you in this process

The two new reviews (TONEAudio and Stereotimes) are driving demand really well right now. 48-hour turnaround is still the norm for now. 

Happy Holiday All - Mark 

Good Morning

Happy Memorial Day

@carlsbad2

Your post was a welcome birthday present – thank you for that.

This is just Audio and it should be fun – it’s that here, and I’m still enjoying myself.

Appreciated your perspective…


@ozzy

Well spoken and well said. We are all just trying to eek out all we can from our systems.

I learned long ago that everything in the chain matters. EVERYTHING.

Those that want to be exposed visit and enjoy the space here. Glad for people like you…


@vandy357

Enjoying right along with you. I think that too often the point is missed – lets get all we can from our huge investments here. I’m doing that – and I’m really pleased with the results.


@lalitk

To be candid – I’m not sure yet. Won’t be a fortune as that goes against my personal goals for this product and just in general how I view the INSANITY that’s going on with prices

I am aware of several people developing Sluggos that are REALLY Cutting Edge – can’t say what how much these might be – but again, not silly sauce money. M


@thyname

You have it exactly correct in both areas. Thanks…

Talking about Car Audio SDFB next.

you guys think WE are crazy……… 😊


Best wishes – Mark

@lalitk 

I'm so busy with birthday stuff I forgot to answer a very important question...

We give EVERYONE 1 free re-programming of a Fuse Box 

If you decide to re-program yet again... it's easy, but we will charge 25 dollars

Many thanks for the nice e-mails well received - I WAS missing some important facts. 

Appreciate the very nice interest in the SDFB

Best to all - Mark 

 

@thyname 

Oh yes - jasonbournexx - the gift that keeps on giving.

My favorite part is this

This thing is just an SCR crowbar! It is made of four parts: a silicon controlled rectifier (thyristor), a zener diode, a resistor and a capacitor.
 

My word. SDFB is under MicroP Control ++ Hall Effect etc. etc. 
 

What can I say... 

@lalitk - if you need some advice - here to help   verafiaudiollc@gmail.com 

 

There are two really wonderful things I love about my job

I really enjoy bringing musical enjoyment into the lives of people in some small way

and – getting to know many of you…

All the rest, it’s just part of what’s in between.

@ozzy

Please continue to keep us in the loop 

The SDFB is on a nice roll with great reviews and more end users being added daily.

Thanks - Mark 

@pinwa

Super good question – and the answer is YES, and we’ve delivered several SDFB’s for the magnificent BHK Amps

You need a 10 amp SLOW BLOW with an option we offer for High Inrush Current. Having this under Micro Processor Control allows us to program in .5 Seconds before Power as opposed to .25 Seconds (our normal spec)…

 

Our forum denizen, ozzy has this programming on his twin SDFB’s. In fact, he helped us with this option (thank you ozzy)… You live – You learn (hey wait – that’s a song https://www.youtube.com/watch?v=GFW-WfuX2Dk)

 

Glad to help you in any way with this.

Best wishes – Mark

@ All Canadian Customers

We just made an even better deal with UPS – so no more USPS (waiting and waiting)…

UPS is FAST and Easy to deal with.

Ref the above song – We Lived and We Learned.

Thanks – Mark

@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 



 

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

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 


 

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 

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

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.  


 

@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 

@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 

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 

@thyname 

Thanks so much for the ongoing faith ands trust in our product 

New Reviews about to emerge that will further define what we are doing with SDFB.

Best wishes - Mark

Good Morning

Sad to report that my business e-mail account was attacked according to Google – this account is verafiaudiollc@gmail.com

My backup account is fine – feel free to contact me there – that account is verafiaudio@gmail.com

 

Google says 2 days to fix and recover – maybe.

Thanks – Mark

 

Thanks MacF

Lynn and I surely do appreciate the thanks 

I know your gear well - and I'm very pleased to know we are making a difference in your system. 

Good read - with sincere appreciation

Lynn and Mark 

@jeenam 

Many thanks for your feedback and support of the Swiss Digital Fuse Box. 

Your e-mails really make me very happy and inspire my next steps with this Tech.

Super review just published today from Bruce Kinch at Positive Feedback. An incredible read on many levels

https://positive-feedback.com/reviews/hardware-reviews/swiss-digital-fuse-box/

 

Feeling very proud and happy. 

I've not been spending much time here on AGon - but really do wish to thank all of you that stepped up to try our products. The new web site is up and running - but still a few things to sort. 

Thanks again - Mark 

 

@lexphin 

Always want to share my sincere thanks and appreciation

@kclone 

Thanks for your patience and going on this ride with me 

Best to all - Mark