Fosi Audio Box X5 Phono Preamp Reviewed

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It’s easy, as a columnist, to forget the “why.” Sure, it’s fun to review oligarch audio and even high end into the multiple kilo bucks range, but a vast majority of music enthusiasts just have more important things in life to spend their hard-earned money on than a $10,000 piece of audio jewelry. I am not poo-pooing expensive gear. The clockwork precision and detailed engineering that goes into some high-end gear represent some of the finest works of art imaginable. The unity of art and engineering in truly high-end gear not only comes at a price, but it paves the way for trickle-down technologies and circuit topographies that ultimately find their way into the everyday. It is the reason I will never toss aside my Bricasti Design M1 Series II DAC (review here). I am still waiting to hear a better-sounding DAC …

Ultimately this is the “why” of why it is important to deeply review and understand $109 pieces of gear like the Fosi Audio Box X5 phono preamplifier, especially for those enjoying the vinyl resurgence. Though, for full disclosure, I want to puke each time I am in Walmart and see albums for $49. There is an inherent responsibility for a publication like Future Audiophile to leverage their experienced staff for everyone, especially our music lovers on a budget. Fosi Audio has not failed to deliver affordable and disruptive gear, at least to my ears, in their ZA3 Amplifier and ZD3 DAC so my expectations for the Box X5 Phono preamplifier were pretty damn high. I was hoping to be once again humbled by Fosi Audio’s capability to keep fidelity high and gear affordable, so let’s get this shindig started.

The Fosi Box X5 phonostage in a slick little vinyl-first system.

What Makes the Fosi Audio Box X5 Phono Preamplifier So Special?

The Fosi Audio Box X5 is packed full of audiophile-grade components. Madonna may be living in a material world, but Fosi is thriving in an audiophile one. Fosi has done so by packing their electronics with high-end electrical components at the circuit level. Like all phono preamplifiers,the Fosi Audio Box X5 is an analog device. Precision is especially important in the handling of analog signals because, unlike digital, there is no magic way to recover information or fudge the numbers. It’s analog, man, and that groovy little analog wave can never be recovered once it is tainted. Precision resistors with 0.1% tolerances and low-noise copper lead Nichicon brand capacitors, as well as quality op-amps, are the kinds of thing you will find in phono preamplifiers costing 10 times or more the Box X5’s $109 MSRP.
The Fosi Box X5 has selectable output gains. Depending on the phono cartridge being used, there may be different levels of preamplification required to optimize the sensitive analog signal from the Box X5 phono preamplifier to a stereo preamplifier. Fosi has made these necessary gain adjustments possible in the Box X5, allowing greater set-up flexibility.
The Fosi Box X5 has flat frequency response through the human hearing range. The frequency variation from 20 Hertz to 20 Kilohertz is less than 0.015 decibels. That’s world-class good. Need more? Both channels track together with the same precision, making for a very coherent and smooth soundstage.
The Fosi Box X5 accommodates both moving magnet and moving coil-type cartridges. As one grows in their analog journey, one of the first steps from beginner to novice is to swap a moving magnet (MM) -type cartridge for a moving coil (MC). By the nature of its operation, an MC cartridge is more expensive, but can resolve information better, and is more sensitive to small dynamic changes. It also requires different impedance matching. The Box X5 accommodates this impedance difference via a selector switch on the back.
The Fosi Box X5 matches the same size format as the rest of the Fosi lineup. I had the pleasure of evaluating the Fosi Box X5 with the Fosi ZA3 balanced amplifier and the Fosi ZD3 balanced DAC. Together, the components look lovely and make one hell of a complete high-performance system.

The Fosi Box X5 is one of the best bang for the buck $109 upgrades in the audiophile business.

Why Should You Care About Fosi Audio Box X5 Phono Preamplifier?

Ever since vinyl became popular again, it is simple for a company’s engineering intern to whip up a phono preamplifier circuit and have it made in some bulk electronics factory for pennies. It is 2026, not 1976. This technology is old news and matured decades ago. Thanks to this simplicity, cheap (in both price and quality) phono preamplifiers have flooded the market. The Fosi Box X5 may be inexpensive but sets itself apart by not being cheap. Good analog is hard to do, since it is a very sensitive signal. Quality counts, and the Fosi Box X5 proves this to be true. It has been four years since I reviewed the Schiit Mani 2 phono preamplifier (read here), and the Box X5 is the first phono preamplifier since the Mani 2 that competes with the Mani 2’s ridiculous performance for its meager price. This makes the Box X5 an extremely strong value at $109.99, and it may even be difficult to find a phono preamplifier that sounds significantly better without spending $1,000 or more.

Some Things You Might Not Like About the Fosi Audio Box X5 Phono Preamplifier

The Fosi Box X5 may just be a little too precise for some. Precision is a good thing in audio. The last thing we want to do is distort the signal in any way. However, that is the exact game vintage audio junkies play on the regular. If you have vintage gear, looking for a “vintage-sounding” phono preamplifier, the Fosi Box X5 is not for you. If you are looking to maximize the fidelity of your sound, then the Box X5 will deliver.
The small switches and selectors of the Fosi Box X5 are all crammed on the back panel.Fat fingers beware. If your system has tight cables, it may be difficult to see them and set the switches on the rear panel. Exercise caution and try not to create any accidental ground loops that will blast you out with a 60 Hertz buzz by unplugging an RCA cable while trying to tune in the Box X5’s switches.
The Fosi Box X5 is not a standard-sized component. Yes, the Box X5 goes lovely with other Fosi offerings but, no, it will not fit into a standard stereo rack.

Michael's cat is not really bad luck, he tells us. — Michael’s cat is not really bad luck, he tells us.

Listening to the Fosi Audio Box X5 Phono Preamplifier

For listening evaluations, I primarily used the Fosi Audio Box X5 with the Fosi Audio ZA3 balanced amplifier, the Polk Audio Reserve 200 Anniversary Edition loudspeakers (Check out the review), and my Rega P6 Turntable with an Aria MC cartridge. I ran the whole system with Cardas Clear interconnects and fed my loudspeakers with AudioQuest Robin Hood loudspeaker cables.

Remake after remake after remake – how many times can they possibly remake and remaster an album? Earlier on in my audiophool stage, I fell for buying differently-engineered renditions of albums that were supposed to be better than the originals, but usually ended up just, well, different. A few years ago, Pink Floyd’s Dark Side of the Moon got its 50^th anniversary re-issue. It was the first re-issue in many years I actually sprang for and was not disappointed by its fidelity. The Fosi Box X5 did not disappoint with this well-known classic. The resolution was high enough to snap me to attention once “Time” started. The dynamic signature from the clocks to the first few chords and drum echoes were bold, even by hi-rez digital standards. Once the band entered, the soundstage was acceptably wide and deep, with the instruments and the effects as well-placed as I have heard in more expensive phono stages. The treble was extended, and bass was tight without sounding constrained. During the guitar solo, the guitar was a little more forward than I am used to but never got annoying. I ended up listening from “Time” through the rest of the album.

While I do not go crazy scouring the corners of this blue marble for new vinyl, I am not against checking the clearance bins now and again when I am at Walrmart getting cat litter, or at the local mall acting like the good little consumer that I am. It was on such an occasion that I found a $12 copy of the Twenty One Pilots album Blurryface. Bonus: it was a two-album set on 180-gram vinyl. There is a silliness to music that was mixed then mastered on digital consoles, only to be later dumped to analog, but some music gains a different texture when listened to on vinyl, even if its birth was digital. On the Fosi Audio Box X5 phono preamplifier, Blurryface came to life with an analog magic I deeply enjoyed. On the track “Ride,” the calypso-like beat hopped with a natural flow I did not find to exist in the digital version. The hit of the drums, both on the snare and hi-hats, were true to the instruments, and the small inflections put into the beat were all present with the Fosi Audio Box X5. I found the vocals a little buried in the total picture of the music at times, and a little softer than on the digital version. Not exactly a bad quality, since it made the whole picture of the song more mellow and listenable. I also found the imaging exceptional, thanks again to the Fosi Audio Box X5’s tight-tolerance components. When compared with my SPL phono preamplifier, there was a good deal of information missing, but the Phono is also 25 times the price of the Fosi Audio Box X5. Blurryface was another great listen on the Fosi Audio Box X5 phono preamplifier.

I am a music lover before I am an audiophile, and this means I do like some old jazz and big band. I have found Jimmy Rushing’s album Five Feet Of Soul (buy at Amazon) to be an underrated big band album, anchored by Rushing’s deafeningly powerful voice. The best part is you do not need to get some exotic, unobtanium version of it, it’s simply an affordable gem. The Fosi Audio Box X5 phono preamplifier does Five Feet of Soul justice, too. One very beautiful thing about music made in 1963 is how human it is. There is no digital editing or synthesized instruments. It is all real people, playing real instruments, to make real music. To capture the small timbre changes, imperfections, and dynamic inflections in the individual instruments that create the macro picture of the song is not easy for a component. The Fosi Audio Box X5 captured everything well, and translated the art of the music. Isn’t that what we all hope for when that needle hits the plastic? The Box X5 brough Rushing into the room with me, and the ballsy band blasted into my listening space during the track “’Taint Nobody’s Biz-Ness If I Do,” but was subtle and engaging during the track “Trouble in Mind.” The Fosi Audio Box X5 did what was needed right, even if there were times I wanted a little more. I am not sure I can give a bigger compliment to a $109 phono preamplifier.

Will the Fosi Audio Box X5 Phono Preamplifier Hold Its Value?

The Fosi Audio Box X5 is $109. There is not a large used market/deprecation worry. At these budget levels, components are practically consumable, with no used market.

What is the Competition for the Fosi Audio Box X5 Phono Preamplifier?

Earlier, we touched upon the Schiit Audio Mani 2 phono preamplifier (review here). Schiit sells the Mani 2 for about $40 more than the Box X5, putting the Mani 2 at $149. Beyond the gain adjustment of the Fosi Box X5, The Mani also has cartridge loading and filtering selections to fine-tune your analog system’s performance. The Mani 2 is also the only phono preamplifier under $1,000 that will give the raw performance of the Box X5 a run for its money.

Pro-Ject swings in the affordable game with their $149 Phono Box DC (buy at Crutchfield). Aside from being built by a long-standing, analog-dedicated company that is known for high performance and a delicate but neutral timbre, the Phono Box DC utilizes a dual-mono design that lowers distortion. The Pro-Ject Box DC offers accommodation for MC and MM phono cartridges, but no gain adjustment to fine-tune your system like the Fosi Box X5 has.

A close up of the Foxi Box X5 at Michael Zisserson's place. — A close up of the Foxi Box X5 at Michael Zisserson’s place.

Final Thoughts on the Fosi Audio Box X5 Phono Preamplifier …

The $109 Fosi Audio Box X5 is a high-fidelity phono preamplifier made possible through a focus on quality components and sensible design. The performance for the Box X5’s price is outstanding and important since, in the budget audio world, it is often difficult to sort the wheat from the chaff, never mind finding diamonds in the rough like the Fosi Audio Box X5. The X5’s fidelity may be a little too clean for some who are looking for a more vintage sound to their vinyl, but I had to pick nits somewhere. The reality is, once you get past the $1,000 mark in phono preamplifiers, the Fosi Audio Box X5 begins to lose its luster as more customizable features and higher fidelity become normal. Does it really take a $1,000 phono preamplifier to dethrone the Fosi Audio Box X5? I believe so, and I am pretty sure anyone with a capable set of ears on their noggin, paired with some common sense, will think so, too. Finding extremely high-value components like the Fosi Audio Box X5 phono preamplifier is why I am grateful to be an audio journalist, and sharing these finds with Future Audiophile readers is icing on the cake.

No AI was used in the writing of this article.