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.
I delight in our OEM work as well. Most know we build all of the owned products of Underwood's business (LSA, Core Power and Emerald Physics) as well as the new loudspeaker products for Thomas at Galion. We did build the new Bob Carver products as well and I really enjoyed that as Arnie (Nudell) introduced me to Bob over 40 years ago.
We do build for others that can't be mentioned.
The guys I work with are the real heroes. Grateful for them. Peter Madnick, Dr Viet Nguyen, JP in Germany, Darko in Serbia and Alina in Romania - big shout out to Ace Delorito in the Philippines too. There are others... but without this group nothing gets done.
I'm on the downward arc now - but still having s ton of fun. I have other ideas that you'll see very soon.
Thanks for your post - it's very meaningful to me.
@verafiaudio
I spent several decades in product development and innovation - food innovation to be more precise. It is clear to me that you are a gifted innovator in the audio industry and perhaps in other industries. I have been very impressed with your product ideas and development over the years. Fun stuff!
In the EU - most are at the component as it's easy to send one of our Piggy Tails to them for this part of the connection and theeir cable from the Wall to SDFB IN
'We are working on this. Lots of Discussion with Peter Madnick about this. Both of us want to get the new Swiss Digital Active Cable out first... we think this is pretty special.
I agree moving forward Mark could offer an IEC built-in that would plug into the component. Of course that does not take care of folks like you and I that have the current version. The other thing Mark needs to consider is there are a lot of folks that want to plug the box into the wall or conditioner. Many don’t have room behind the component. In these instances they would need a box with a male three prong connector on it not an IEC. Mark would then need to build two different options 🤓. Not ideal. Many considerations here.
The only thing that needs to change is the AC outlet on the SFB should be an IEC Female.
That way the power cord just plugs into the SDFB and the Female IEC plugs into the component. The problem would be the amount of real estate at the back of the component.
@ozzyYour build is certainly an option and your particular build is very high quality. I think an adaptor of high quality would be potentially as good sounding, lower cost, and for some a less cluttered option. I will build one per my plans above and report back.
Not sure of any made (future) adapter quality. That is; with the connectors, or the wire used.
This is what I posted earlier.
I actually made my own 1-footer jumpers out of the Nanotec Power Strada #308 cable with Furutech NCF fittings. Surprising, the extra cord does not seem to be a hindrance, after all the wire coming through the wall is 10-gauge Romex.
I suppose I could have made it 6" long, (or maybe shorter) perhaps that would be the quick answer?
I am thinking of using AC connectors like these in the link below. This is just an example as there are several well priced options for AC connectors I have used in my past cable builds. Remove the outer cases/shells of both and connect them with an inch or so of great wire or a long Sluggo type of conductor. I would carefully damp and encapsulate to finish.
Be great if you made a high quality adaptor that could plug into the component or wall. Nothing out there right now and I will have to make my own. Not sure of the design yet, but I really don’t want another cord. I also think a top quality adaptor design will sound best.
The cheap ones for $5 don’t use high quality conductors or construction.
Purchased two Swiss Boxes and will report back vs SR Master and Purple fuses. Decided to go with cheap adaptors until I can make my own of much better quality.
All part of the "Graphene Magic" (which is really just a healthy dose of science)
Further - our Black Friday is on and we are getting ready for the release of Swiss Digital Active Cable. Fully Active all Conductors (not just the Shield) - more to follow
@ozzyI have 3 Graphene sluggos now and feel they were a noticeable improvement over Solid Silver, Hollow Silver/Rhodium and Gold plated copper. The graphene sluggos sounded very good new and have improved with curing hours. Mine are at about 200 hours and seem to continue getting slightly better. I do notice they get quite hot compared to the other sluggos.
Please note that Graphene requires "curing time"- but very worth it
40 hours - 75 percent
150 - 85 ish
400 - 99 percent
So, my return comment to him was:
Thanks for that information. First listen and I do not detect much difference from the copper sluggs I was using.
I don't believe it to be possible, but can they also be directional?
ozzy
I think, I have read that they can take a little time to break in. Not sure if I understand why but can anyone with experience with the Graphene sluggos comment.
You can build four awesome, top tier 9.75 inch power cables with 1 meter of Furutech DPS 4.1 cable, and four pairs of Viborg VM503R/VM503F connectors. They will total to about $132 each. Or build three at 13 inches long for a little more. (See vh audio and AliExpress)
Or you can use the cheaper Furutech FP-TCS31 cable and they will be $100 each.
Lastly, you can use cheap IEC C13 to NEMA 5-15P to IEC adapters (in the US), and they are only $6 each and sound good because the length is so short, but they will bend under the weight over time.
Sound quality is DPS 4.1 > FP-TCS31 > C13-to-5-15P adapter, but the sound quality differences are somewhat less impactful in the position upstream from the SDFB than whatever power cable is used downstream from the SDFB, and which connects directly to your component.
I would recommend the DPS build route for people like you, and the adapter route for people on a budget.
I hear ya about the need for another power cord. I am using AQ Dragon power cords to my amps.
I actually made my own 1-footer jumpers out of the Nanotec Power Strada #308 cable with Furutech NCF fittings. Surprising, the extra cord does not seem to be a hindrance, after all the wire coming through the wall is 10-gauge Romex.
Something to consider is all these audiophile fuses degrade in sound quality over time according to Synergistic Research owner Ted Denney. I was going to try a Pink fuse, but knowing this I am not sure I would spend money on these fuses with this information. I like that he was honest.
The Swiss box is interesting, but bulky and will the added pigtail hurt sonics when added in series to my “awesome” sounding power cord 🧐 If one could avoid the pigtail and use an adaptor, then that may be the best sonic option?
To me, in my mind, the claim to fame of the Swiss Fuse Box (SFB) is in the fact that it eliminates the very skinny wire in a fuse and replaces it with a more robust connection (sluggo). However, my amps are very powerful and each Mono Block takes a 20A fuse, so the fuse wire cannot be that thin.
I have had every iteration of the Synergistic Research (SR) fuses and the Pink seems to be the best. The bass is more accurate and the sound stage is wider. But I did think that the upper frequencies were perhaps a little more subdued. Possibly a plus for some amps/speakers that may be a little bright.
My first impression (cold out of the box) of the SFB Max variant, I thought they provided more liveliness. And the upper frequencies sounded more involved. But this could be due to the need for more break in. The next day a little more bass depth appeared. And now after 70 hours the soundstage is expanding. I was playing a few live tracks last night and I was impressed with the width and the depth with the SFB compared to the previous SR Pink fuse.
The sluggo I am using is the super copper emersion version. I do wonder if the Graphene version would be even better. Or is the graphene version more useful in source equipment? I dunno, but I would like to experiment with that version someday.
I found a small, immediate improvement in my Aries Cerat Kassandra two Reference DAC. In general, I think at least 50 hours and many people would say you need 300 for any tweak to totally settle in.
I will be comparing the Swiss Fuse Box to a Synergistic Research Pink fuse. My amps require 20A fuses, so it took quite a while to get 20A versions of the Fuse boxes, but they finally arrived.
Question:
As usual, most things audio do take some time to break in. Anyone have a recommend time frame?
@thecarpathian Thanks for walking back a little there.
The learning about and practice of forgiveness is one of the most profoundly important things in human life, at least that’s how I see it. There is also the intention to understand rather than to judge, without being naive and taken advantage of.
Many people on this discussion forum have been aware of Mark’s somewhat distant past for a significant length of time, and yet they have still given him business and high praise regarding their actual experiences in interacting and transacting with him. I’m one of those people, even though I don’t think I’ve bluntly stated it online... until now.
You’re right, that was a bit harsh. You honestly seem quite a decent fellow.
Here is what I don’t understand;
How can someone, especially a decent fellow, so enthusiastically advocate for a product knowing what they know about the man heading the company?
Personally, I couldn’t do it. I don’t care how amazing one may think the product is. I simply can’t separate the two, and wouldn’t lift a finger to benefit such a person.
I read the article you guys are referring to some time in early 2023, so I’m aware. It has nothing to do with me or what audio products I discuss here. The above comment that my posts here "amounted to nothing but advertisements praising his products" and the "read between the lines" comment are twisting facts to vaguely accuse me of some sort of malfeasance. My historical contributions to audio related discussions here vary greatly, including some criticisms of VeraFi Audio products. I don’t like being wrongly accused, so I’m defending myself, not "deflecting".
It’s not accusatory, it’s correct. I do like your ’conspiracy theory’ and ’benevolent intention’ comments though. Nice attempt at deflection. By benevolent intention, do you mean like how the owner of the company benevolently scammed people out of their money and charities like children’s cancer research? Despicable.
That is very accusatory, to say the least. This isn’t a conspiracy theory website, it’s for discussing home audio products. Save your keystrokes for something else -- perhaps consider focusing on a benevolent intention.
Small update -- I’m now waiting on a couple more graphene sluggos to arrive and burn in a bit before doing final, focused testing between the G-slugs (😁) and the mirror-polished copper slugs, as there’s some subtle differences that I’d like to define better in my mind before trying to language it here.
It’s hard to believe that we now have a Sluggo that is better than the mirror-finish polished copper Sluggos, all of which I hand polished myself and have exclusively been using in my components almost this whole time.
More thoughts to come soon about the Graphene Sluggos...
I Purchased a Swiss digital fuse box and installed it in my PS audio P5 power regenerator. My only issue now is whether I should buy two or four more.
I do not need to be saved. You do not need to worry about my money and how I spend it.
I do not appreciate comments from people who do not own or use this product. If you have not installed it in your system, you have no idea what it will do for you. Also, if you installed one in your system and your house burned down, I would love to hear from you.
Nice to see the review in Positive Feedback. However, I’d have some choice words for Bruce.
Let’s just cut to the point of what a review regarding the SDFB should make very clear. By removing the thin gauge fuse from the power signal path, it’s basically removed the resistance caused by a traditional fuse. Plain and simple. If a system sounds worse with the SDFB installed (e.g. brighter), it’s because THAT’S HOW THE COMPONENT ACTUALLY SOUNDS. It’s not the fault of the SDFB. The SDFB merely allowed the component to sound as it would if there were no restrictions in the power path.
There should be no apologies for that. The veil was lifted from the component. You can only polish a turd so much, as they say. If you find out a component sounds like a turd after installing the SDFB, it sounds like a turd because it’s a turd. Don't blame the SDFB for disrupting the synergy between components. Sheesh.
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.
Copying emails I sent to Mark regarding my experiences with the SDFB:
2/10/24
I’ve had the speaker amps powered on for 10 days straight now. The best description I can give would be the SDFB’s modify the sound akin to a sampling rate upgrade from 44.1 to say 96kHz. Everything is cleaner and more detailed. Soundstage is wider, deeper and taller. Cymbals sound more like cymbals. Imaging is sharper and sounds project forward into the soundstage like never before. If the soundstage is not flat in the recording, it comes through now. Decay is more apparent due to the lower noise floor. The sound is now finally coherent. When I first listened with the SDFB’s plugged in it did not have the coherency top to bottom as after 10 days of burn-in. I’m pretty sure the Paradigm Active 40v2 speakers are maxed out performance-wise with these. With my Job 225 amp & Ascend Sierra Towers w/ RAAL tweeters I can probably discern more of an in improvement in bass frequencies, but I suspect the 40v2’s have reached their potential. If anything, they now sound closer to what I would expect from good quality mid/near-field studio monitors (e.g. ATC, PMC, K&H) in regards to detail retrieval. The 40v2’s are never going to compete with the transient response of RAAL tweeters or my Rythmik F12 subwoofer which has servo technology to reduce distortion.
2/13/24
I recently decided to have a listen to one of my favorite acoustic playlists and in all honesty, the Active 40v2’s sound better than I can ever recall the Ascend Sierra Tower w/ RAAL + Job 225 combo. I’m definitely looking forward to pairing the Job 225 with a SDFB to compare. Based on the results that I’ve heard so far with the Paradigm’s, my money is on the SDFB taking things to the next level. As you are well aware, the SDFB’s are the real deal. I’m sold, literally.
All in all I’d say the SDFB’s are the single best purchase that I’ve ever made. Previous experience with changing interconnects and power cords led me to believe that replacing the fuses in my gear would result in a noticeable upgrade in sound, but I didn’t want to take the chance that a fuse would randomly blow and my investment would be all for naught. The fact the SDFB’s aren’t at risk of going bad led me to take the plunge and I am thrilled with the result. The power cords I’m using with the Paradigm Active 40v2’s are Iron Lung Jellyfish, which can be had on Amazon for $17/ea.
If you’re on the fence about ordering these, you really have nothing to lose since there is a 30 day no questions asked money back guarantee. However, as I told a friend of mine, if you order the SDFB you’re not going to want to send it back.
I thought I would weigh in. I originally ordered the SDFB for a Puritan PM136 power conditioner. Unbeknownst to Mark and I the new ones do not appear to have a fuse. He had done some SDFB for the Puritan in the past, but those must have been older models. So we couldn't use it there. I decided to try in on my McIntosh MA 8950 integrated amp. I had my reservations about trying it there because I had an expensive power cord (Hijiri Takumi) and didn't want to put anything in the chain to mess with that. I had to wait a few days for a newly programed SDFB and Sluggo for the MAC. Came in and set up was easy. I started playing some tracks and I was thrilled with what I was hearing. I really liked the sound of my system before the SDFB, but with it in, the sound from my Polk R700s expanded, got bigger, or better sense of space and everything sounded so much more relaxed, but not in a boring way. I texted Mark, that I didn't know the Polks could sound like that.
A pair of these finally arrived. Speakers are Paradigm Active 40v2, DAC is Chord Mojo, source is WiiM Mini (optical), format is Apple Music lossless.
Just posting a quick impression. Details to follow later. The SDFB’s have been plugged in for less than 24 hours. The upgrade in sound is akin to, and and in some areas exceeds the jump going from 16-bit 44.1kHz to 24-bit 96kHz. These are legit. Mark stated the increase in resolution won’t reach ~75% until they’ve been powered up for 40 hours so this is a great start.
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