The Caldera 10s blend nicely with my Wharfedale EVO4.2s (big bookshelf speakers). The 10s were initially a little boomy in my small room, but blocking the vents yields pleasingly crisp bass. I plugged my integrated amp & the 10s into a "smart power strip" - so that switching on the amplifier energizes the outlets for the 10s. I'm really pleased with my purchase, and I'm relistening to my whole collection to hear the improvement.
Having ordered and installed two of these in the past, one on my Lampizator DAC and the other on my PrimaLuna Evo 400 preamp, I was smitten as these devices made perhaps the largest difference in sound quality for the smallest expenditure I had ever made. So, two more were ordered for my tube mono block amps, they arrived, I installed and both popped as soon as the power was turned on. I contacted Mark and we both agreed that the inrush was too great for the delay so he graciouslly agreed to send me two more with an extended delay to fix the issue. As much as I’d like to say the second set worked perfectly they failed in the same way only it took a little longer. I once again contacted Mark and he then had his engineer get hold of me and we solved the problem by simply doing an amp draw at start up. The new units were designed to work with my amps start up draw and they worked perfectly. My thanks to Mark and his crew for taking the time and having the patience in dealing with this frustrating issue. Now, what have they done for the amps, all I can say is they have an extended range, I am hearing more music, there is a clarity that just wasn’t there before and I find myself listening far more than before. Very pleased with the purchase and very pleased with the company.
I suggest an amperage control to make this device adjustable.
Not a lot of subwoofer experience but after reading reviews by a trusted reviewer and based on affordable price, I took the plunge. Not regretting anything about it. My experience so far has been very satisfying.
If this is all the money you can eek out, you can quit looking here. I can't imaging any other sub that can perform this well for this price.
I used this in conjunction with the snub way noise defender. Bass is fuller, treble is sweeter and instrument separation is enhanced. Overall a noticeable improvement in all aspects of sound quality. My system is: Zu Audio DW6 superfly speakers, HiFi Rose RA 280 amp, Denon DCD1700 ne CD player, Eversolo DMP A6 streamer, Schitt Jotunheim II headphone amp and Audio Technica ath WP-900 headphones. Cables/interconnects are Zu Audio Mission II's.
Definitely one of the best investments I have made to my system. I would never have believed it had I not heard with my own ears. Everything opens up and it brings out details I have not heard before.
I will be adding more to my other components in the near future.
I am convinced that the Swiss Digital Fuse Box makes an improvement in the sonics of my system. The idea of an out-board fuse is novel, effective sonically and cost-wise the way to go.
I'm up to 5 SDFB now! The latest is for my DSPeaker X4. Cold out of the box with a new piggy tail, everything is noticeably improved. You immediately notice the ease of delivery, what we used to refer to as 'space between the notes' when describing analog vs digital back in the day. Over the next 24 -72 hrs, the sound continues to settle with improvements across the board. The balance appears to warm up, but with no loss of detail. The soundstage increases in all dimensions, images become more palpable, depth expands but with additional specifity. Most importantly, I am listening to many more recordings from start to finish including ones that are new to me. And appreciating all of the artistic nuances of singers, instrumentalists, recording engineers, etc. This product has finally stopped me from spending a small fortune each time I try to squeeze out a 1% gain in the performance of my system. These units have no peer. Well done Mark!
I’m based in the UAE, and we’re already in the heart of summer. While the temperatures rise, there’s still so much to enjoy—cool breezes by the beach, busy streets full of life, and even air-conditioned bus stations that make city life comfortable. That said, during this season, with all the cooling systems running constantly, our power grid can occasionally introduce high-frequency (HF) electrical noise.
About a month ago, I installed the SnupWay Noise Defender and Main Stream Line Conditioner from Vera-Fi into my unused power outlets. Initially, I was skeptical. I did notice cleaner high frequencies, but the sound felt slightly dry at first—something was happening, but not exactly what I expected.
I reached out to Mark L Schifter, and he encouraged me to give it 400 hours of continuous use. True to his advice, after four weeks, the system truly opened up. Now, the sound is natural, warm, musical, and full of depth and detail, with excellent transient response.
Even though I already had a solid power setup, Vera-Fi’s products added an extra layer of refinement—bringing out the best in my system despite the seasonal challenges. Highly recommended for anyone seeking to elevate their listening experience, especially in dynamic environments like ours.
Very surprised at the quality for the price.
After I installed Vera-Fi's Main Stream, SnubWay and the Swiss Digital Fuse Box, my patient wife asked me if I was happy with my latest upgrade to my power tube sound system. I answered in the affirmative, I'm thrilled! She knows how hard I am to please when it comes to what my ears hear. I'm always trying to get that last percentile of quality out of my stereo. And right now I couldn't be happier. In closing, CroTone Tubes are the best sounding tubes made in the USA.
Really great speakers. And the best part: excellent customer service if you need anything!
The project scope and requirements were clear: significantly upgrade the audio portion of our family room video set-up without killer expense or upsetting my wife's aesthetic sensibility (listening room / office is all mine for aesthetic, rest of the house, not so much :)). Out went the old, but decent, stereo amp and a pair of well known and highly praised but LIFELESS budget speakers, in came a trio of VS's to go with the in-place Caldera sub (for a 3.1 system) and KAPOW! Life in the audio portion, dialog clarity, frequency extension, and more, fitting at last for the picture on an LG OLED TV. Mission accomplished thanks to Mark and his crazy helpful way of doing business. Buy a pair. Buy 6 pairs and give 5 away. You can't go wrong and what a great speaker for the budding audiophile in your life.
Once this unit is hooked up and balanced, its tough to beat for value. It makes cheap speakers sound better and better speakers punch way above their weight class. Very solid and versatile piece of kit. Glad to own it.
So…
I plugged the Mainstream and Subway, sat and, well nothing! No change at all. A little disappointed to say the least. And then, literally a couple minutes later it began and increased over the rest of the evening. By the end of the week I was astounded and promptly ordered two more! Improvements across the board, most noticeable was a greater musicality, richness and body to the music. More natural, less harsh or forced.
When the second set arrived it was the same thing. With two pairs in my system now, it’s a component level change. Once of the best improvements for the costs ever. Thank you
I had check-boxed fuses off as a facet I wouldn't bother toiling over after 'sampling' a couple Hifi fuses and coming back to the stock fuse the manufacturer supplied and used while designing and trialing their product on both counts.
In short, I had come to the conclusion that Hifi fuses are not for me as both added coloration.
Enter the SFDB. It works without adding coloration. Everything opens up, is more resolved and dynamic, and with a noticeable drop in 'digitus'. I am not a believer in Hifi fuses, but can hence highly recommend the SFDB.
Additionally, communication with Mark, and others at Vera-Fi Audio, has been a pleasure.
After integrating both the SnubWay and Main Stream into my system for an extended period, I can confidently say they have become indispensable components in my setup. From the very beginning, the improvements in low-frequency articulation and control were immediately apparent. The bass not only gained in weight and presence but also exhibited a remarkable refinement, offering better layering and definition without overwhelming the rest of the spectrum.
The SnubWay contributes by subtly reducing background noise, allowing micro-details and textural nuances to surface more effortlessly. Meanwhile, the Main Stream enhances the power delivery with a natural, unforced energy, resulting in an organic flow to the music that feels both more vivid and coherent.
What impresses me most is the way these two devices elevate the emotional engagement of listening sessions. The system now breathes more easily, with a blacker background, sharper imaging, and a more lifelike presentation across genres—from classical orchestration to complex jazz ensembles.
It is rare to encounter accessories that make such a profound impact without altering the core character of the system. I am truly grateful to Mark for offering these outstanding products, which have taken my system's performance to a new level of musical realism and immersion.
I purchased the this little subwoofer after watching several YouTube videos where the reviewers were impressed by the build quality and sound. With a 3 year warranty, I felt I had nothing to lose, so I bought it. When I hooked it up, something wasn’t right, so I called Veri-Fi Audio customer service and left a message. The owner of the company soon returned my call and walked me through some steps which had the sub working perfectly. I am very happy with the sound of this unit and plan to keep it. I am even more impressed with the service I received. Dedication to customer satisfaction is rare these days, and Mark from Veri-Fi Audio has made me a life-long fan! I will be buying more products from them soon.
That's nothing to be said. Fantastic products and still purchase more.
Howard.
I wasn't sure what to expect when I initially ordered a SDFB and graphene sluggo for my DAC. After reading many positive user reviews and speaking to a dealer in my area who recommended them highly, I decided to take a chance and place an order with Mark.
After an easy installation process, I was quite shocked with the sound improvement. Vocals are now much more present, improved separation, soundstage and depth/layering. The music flows from my speakers with a relaxed ease. I was so impressed with the results, I immediately ordered 3 more. One for my preamp, power amp and switch. Each fuse box made noticeable improvements in my system, especially the ones on my DAC and switch. Very impressive performance improvement for a relatively low cost compared to the other components in my system. The only negative thing I can say about the fuse box is if you try one, you may end up wanting one for each component in your system!
Everything you've read but Mark in the other reviews is absolutely true. He's a truly wonderful guy to deal with. He was always quick to respond to all my messages and went out of his way to ensure I got the properly configured fuse boxes for each of my components. If you have any questions, don't hesitate to send him a message, he's a real pleasure to deal with.
Vera-Fi Audio has quickly become one of my favourite Hi-Fi companies in 2025. Highly recommended!
I received fuses a month ago for three Pass Lab amplifiers used in dual amplification: two Pass 60.5 XA for low frequencies and one Pass 30.5 XA for high frequencies. After changing the fuses I can say that the swisse box do a very good job. At first I used them with gold sluggoes, already with very good results, at a later time I replaced them with graphene sluggoes (obtained on very good terms and being able to take advantage of an offer although I had bought them a few weeks earlier). Thank you Mark I appreciated this sales ethic in a profit-driven world.
I must preface this by saying that what convinced me to purchase, beyond the enthusiastic comments I read on these pages, was the logic behind this project. Those who, like me, compose their systems with countless electrical devices often get the result of both enhancement and degradation. In addition to EMI and RFI interference, ground loops, and noise generated by each device that is added, one should not forget the degradation caused by these funnels that are the fuses that actually multiply the bottlenecks in the acoustic signal path in proportion to their use: in my case a cascade of switches, a Clock, a streamer, a DCC, a converter, a preamplifier, and three power amplifiers. The project of removing these bottlenecks seemed to me a simple and enlightened idea to pursue the most neutral position, which is that of a device with the best possible power supply. I will give below some suggestions to eliminate in my opinion the risks due to the suppression of the physical fuse with the electronic one.
I waited a break-in of a hundred hours before moving on to a critical listening of the results obtained. Not only were the changes already convincing, but there was further obvious room for progress with the graphene sluggo version. After swapping the old Synergestic fuses (orange and purple in my case) for the swisse fuses with the gold sluggoes, I caught a better homogenization between the two frequency bands in the bi-amplification. Another rather noticeable nuance emerged in the spatial delineation of instruments, particularly voices. The previous fuses seemed to enhance the midrange or treble depending on the model, but at the expense of the edges of the instruments and voices, which found themselves no longer placed in a delimited space relative to other voices or instruments. In other words, it seemed to me that in the old fuses the greater efficiency was achieved at the expense of the separation and contours of the elements on the soundstage being less precise. With some recordings, such as Pergolesi's Stabat mater in Abbado's recording, the voices of Margaret Marshall and Lucia Valentini Terrani are now better separated and more similar to the reference obtained in headphones. With the graphene sluggoes the whole range and in particular the basses have improved in articulation, speed and in the case of the basses have become tighter and more dynamic. Very often we remedy one of these degradations by unbalancing other parameters. In other words, we correct an alleged imbalance by introducing other imbalances in a chain of errors that balance each other out. The temptation, needless to say, is to proceed with the elimination of the other bottlenecks, wallet permitting.
A word of advice to finish up : in the use of fused swisse in amplifiers or other devices with stand-bye set-up precautions are to be considered. Due to the fact that swisse fuses take a few seconds before the green light comes on making the defense of your hi-fi devices effective, following a blackout of the mains or home electrical panel, the stand-bye position could result in power arriving before the electronic fuse is activated. I therefore recommend that you take the precaution of turning the device off, wait for the light to change to green before putting it on standby.
Thank you in any case to Mark and his team for the pleasure this new listening brings me.
Alessandro
Very pleased with the Graphene Sluggo. Not fully cooked yet and might take a while longer as I don't leave my amp powered up, but the easiest way to put it is smooth with an increase of information. Pleased enough that I will be ordering for the rest of my gear in the near future.