Vera-Fi Audio Swiss Digital FUSE BOX by Greg Voth

A while back, I received an inquiry from Vera-Fi Audio, asking if I’d like to offer my impression of their Swiss Digital FUSE BOX. When I agreed, we discussed the fuse values in some of my components. My SBS Design S2 Pro power amp was off limits because its fuse complement consists of four individual fuses (and QSA Red-Black). With a current FUSE BOX limitation of 10 Amps, the SBS was out of bounds… but my Opera Consonance M100SE tube integrated fit the bill nicely.

Two other Swiss Digital FUSE BOXes (herein SDFB) arrived, one for my Conrad Johnson PV-5 and the other for my LSA Discovery Warp 1 power amp. The Warp 1 has had a Quantum Science Audio “Yellow” fuse in it for some time. The PV-5 suddenly developed a non-playable condition, and I’ve yet to send it off for diagnosis and repair. When demonstrating the SDFB to my brother-in-law, who also has a Warp 1 amplifier, he was so enthusiastic about the Swiss Digital FUSE BOX that he borrowed the Warp 1’s SDFB to hear at home and has yet to return it.


Each SDFB is factory configured by Vera-Fi Audio based on a component’s fuse rating info provided by the component’s owner and remains specific for use only with that component. The SDFB manual clearly states that fuse value accuracy is paramount for using this product rather than the component’s internal fuse. The SDFB manual states. “The Consonance M100SE fits the bill nicely since its fuse rating is at the top limit that the current Swiss Digital FUSE BOX SDFB can replace. Also, being integrated, its single fuse handles protection for both its preamp and power stages that might make any improvements during listening tests between the original fuse and the SDFB more evident.”


You Must Read the Manual

Once you’ve contacted Vera-Fi Audio and provided the necessary information about your component’s fuse requirements, a Swiss Digital FUSE BOX will arrive with its manual and a packet of fuse-shaped metal slugs in brass and copper. The fuses in audio components are typically either a .25 x 1.25 or 5mm x 20mm: they send 1 of each in brass and copper. Note: There are no internal settings that the customer can alter themselves – should you wish to use your SDFB with a different component and its fuse value is within the current 10A range of protection offered by the SDFB, you can return it to Vera-Fi Audio for internal setting change. Once differently programmed, the SDFB can no longer be used with the original component.

You’ll see “THE FUSE BOX WARNING” on the cover of the 4-page manual. You MUST read the manual! After all, we’re discussing the proper fuse value that protects your component from harm. Keeping your baby safe is on you. On page 2, you’ll see the following, “If you have gotten to this point in installing FUSE BOX in your system, it means you have acknowledged and accepted the consequences of improper use of this product.

“If you are having second thoughts, please STOP RIGHT HERE AND DO NOT OPEN THE SEALED BAG CONTAINING FUSE BOX. BY OPENING THE BAG, YOU ARE ACCEPTING ALL RESPONSIBILITY FOR ITS USE” There are ample warnings throughout the Swiss Digital FUSE BOX manual that protect you and its maker from physical and financial harm.

The Swiss Digital FUSE BOX

With all that intense jargon out of the way, let’s look at the unit itself. The Swiss Digital FUSE BOX is an unassuming unit, 5” in length, 2.75” wide, and 1.5” thick, with a silver chassis, rounded sides, and black end receptacles, one being a 15A female connector and the other a female IEC. The 15A end sports a green LED to let you know that power’s getting to the unit. A badge sits atop the unit, identifying the SDFB by name, and a label is affixed to its bottom, denoting its setting. In the case of my Opera integrated, the label reads “10 Amp Slow Blow” in easy-to-read font size. To use the SDFB, you’ll need two power cords, as the SDFB sits inline between wall power and your component. Use whatever comes to hand, or order a short cable from wherever you want. Vera-Fi Audio has recently begun offering a high-quality Core Power Technologies power cable PIGGY TAIL 1 Footer, which can be purchased with an SDFB at additional cost. It is a nicely constructed, hefty cable affixed with Furutech hardware on each end. Conversely, one could use a Nema 5-15p to IEC C13 adapter if you can solidly support the FUSE BOX (and power cable) sticking directly out of your component’s IEC 15A receptacle. There are audiophile-quality adapters on The Cable Company site from VooDoo Cable that are cryogenically treated in cold fusion and listed as handcrafted in the USA.

Once you’ve located your component’s fuse and replaced it with one of the FUSE BOX slugs of proper length, you leave your component switched off while attaching cables to each end of the SDFB and connect your cables to your conditioner) and component, prior to switching the component on. Once on, that’s it. Note: The default condition for the relay is OPEN, so if there is any failure, no current can flow to the attached device.

Results of Numerous Listening Sessions.

I’ll cut to the chase. When playing our Consonance M100SE tube integrated using Vera-Fi Audio’s Swiss Digital FUSE BOX, the combination delivered a sense of greater depth and an improved render of acoustic instruments in space. Dynamics are punchier; transients snappier; bass had far more body, and female vocals breathed with added life. The Swiss Digital FUSE BOX accented the intimacy and closeness of the performance and enhanced the sense of stereo as more natural. More heft emanated from the integrated as music entered the room with more “oomph.” Things seemed both more lively and more relaxed. As aforementioned, a waft of greater headroom tickled my senses, along with added resolve. The sound of the SDFB in this simple setup made the music more detailed and smooth, imparting a sense of ease during a listening session. There was just more there, there. I’ll leave you with a few examples that prompted my positive comments above:

Lee Pardini’s homebodies (GroundUP Music) got me through a big chunk of 2021’s pandemic isolation, as I listened to the entire album daily for months. Despite being wholly instrumental, there’s something musically optimistic about this project. With this first play of the opening track “whatsoever,“ with the SDFB and Core Power “pigtail” cable in the tube integrated, I was honestly surprised as far weightier low frequencies jumped forth, and the music flowed with a greater density, adding notable interest. Stage depth was also better rendered.

When I put on “Nublado,“ from Sera Una Noche’s self-titled Ma Recording’s 1999 release, my wife asked me why I play that particular song so frequently. I responded delicately, sharing that the music we know well and frequently hear better informs us of differences in component performance. “Just listen to that bass clarinet,” I said. This oft-played song breathed with added life and greater acoustic resonance; the instruments held a stronger presence in the acoustic space, and the bass clarinet sang with more palpable harmonic detail and instrumental depth. I chuckled as the lyrics came to mind from King Crimson vocalist Adrian Belew on 1981’s Discipline release, “I repeat myself when under stress, I repeat myself when under stress, I repeat myself when under stress, I repeat myself when under stress, I repeat…” (“Indiscipline”). Through multiple plays of two of Melody Gardot’s songs that I play unceremoniously often here, “From Paris With Love (single version),” from Sunset In Blue (2020 Decca Records), and “So We Meet Again My Heartache,” from The Absence ( 2012 Decca Records), Gardot’s voice was warm, fleshy, and tightly controlled as her honey-soaked low, breathy timbre coveted the space between the speakers. The instrumental depth and stage depth was better on “From Paris With Love (single version),” a larger venue. However, both recordings created an intimately nuanced, dynamic, and dimensionally breathing space, perfect for the singer.

The Wrap

For those out there who assume swapping in higher dollar fuses a fool’s errand, the Swiss Digital FUSE BOX offers an option you can wrap your head around. If you need it on a different component with a fuse rating of 10 amps or under, give Vera-Fi Audio LLC your new setting requirements, and they’ll alter the interior settings to suit. Look, Ma, no fuse!


greg voth  

Swiss Digital FUSE BOX: $395US. 

The SDFB has two metal slugs (.25 x 1.25 and 5mm x 20mm), copper, and brass. A Core Power “Piggy Tail 1 Footer” power cable with Furutech hardware can be purchased with an SDFB for a combined price. Vera-Fi Audio offers a 30-day No Questions Asked Return Privilege on everything they sell.


Vera-Fi Audio LLC 




Phone: (818) 584-6870

3 thoughts on "Vera-Fi Audio Swiss Digital FUSE BOX by Greg Voth"

  1. Ryan says:

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    1. ngfmarketing says:

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