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.

My initial experience has been overwhelmingly positive—Mark L Schifter and his team are consistently responsive and supportive whenever I reach out. Beyond that, his products deliver outstanding performance and excellent value. I’ve already placed additional orders, and a few more items are now on the way.

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!

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.