Fosi X5 Phono Preamp: A Budget Stopgap That Surprised Me

I wanted to spin a new jazz record: Preachin’ by tenor saxophonist Gene Ammons. As the needle approached the end of side one, I noticed a crackling in the right channel that was definitely not part of the recording.

The culprit turned out to be my beloved DIY XONO phono preamp. Its right channel had developed a fault. Even with the Clearaudio turntable disconnected, the noise was still there, and the VU meters on my Eversolo DMP-A8 were dancing like crazy. I pulled everything out of the rack, and a weekend of troubleshooting followed. I replaced the BC550 and BC560 transistors, but that didn’t fix it. As I write this, I’m still swapping semiconductors on the defective board to bring the XONO back to life.

What do you do when your phono stage dies?

Vinyl listening doesn’t stop just because the main preamp is on the bench. I needed something cheap that would carry me through until the XONO was back in business, so I started looking at budget options.

I came across the Fosi X5 as recommended by the Audio Science Forum, where users were raving about its performance. Fosi is a Chinese manufacturer that specializes in affordable, entry-level audiophile gear, and I had only ever heard good things about the brand. The X5 happened to be on sale on Amazon for under €100, so I ordered one.

The X5 is aimed at first-time turntable owners, but it also makes sense for audiophiles whose integrated amplifier has a mediocre phono input.

Honestly, I didn’t expect much. I used to own a first-generation Schiit Mani, a decent unit that was easily outclassed by a friend’s HiFiAkademie phono preamp. My DIY XONO beat both in every way, with more dynamics and more resolution across the board. Against that background, a sub-€100 box had a lot to prove.

First impressions and build quality

The X5 arrived in a small cardboard box, and my first impression was how nicely it’s made. The tiny aluminium housing feels solid, and the design is minimalist, with a single orange button on the front.

The back panel is just as spartan. The only adjustment is a gain switch (38 dB, 48dB, 56dB, 66dB are the only choices – I chose 38 dB at 47kOhm which is perfect for MM cartridges and my Clearaudio Maestro MM). The X5 supports both MM and MC cartridges, but you can’t tailor it to your cartridge: no capacitance or resistance loading, no rumble filter, none of the extras that pricier competitors offer. For my Clearaudio Maestro V2 MM, that simplicity is fine. If you like to fine-tune your cartridge loading, look elsewhere.

Powering on and off: To turn the Foxi X5 on, simply hold the orange power button – to turn off, hold that same button for about 2 seconds.

What’s inside

I haven’t opened my unit because I don’t want to risk the warranty, but photos online show a surprisingly sophisticated design for the price:

• Three op-amp topology: two OPA612A op-amps, soldered as non-replaceable SMD parts, and a socketed Texas Instruments NE5532P buffer that you can swap if you enjoy op-amp rolling. I would consider a TI LME49720 or LM4562 which are both pin-compatible to the NE5532 and on paper offer better noise characteristics
• A proper power supply: instead of the usual cheap switching wall wart, the X5 uses a true 16 VAC transformer, converted internally to clean DC by classic LM317/LM337 regulators. That is both unusual and very welcome at this price. Since the X5 takes AC, an aftermarket linear DC supply isn’t an option, and thankfully it isn’t needed
• Good components throughout, which belies the low price tag. It seems the Fosi designers have done their homework here

Listening impressions

My setup for this test: my very own Clearaudio Performance SE turntable, a Clearaudio Maestro V2 MM cartridge, and Elac Vela 404 speakers with Elac AMT tweeters. I was curious how such an inexpensive box would cope with that kind of front end.

From the first record on, the X5 didn’t seem out of place. Everything sounded clean and crisp, just as I’m used to. The only flaw I noticed was a slightly higher noise floor when I put my ear right up against the sensitive Elac AMT tweeter. From my normal listening position, I couldn’t hear any noise at all.

Fosi X5 vs. my DIY XONO: smaller differences than I expected

I didn’t do a direct A/B comparison. The XONO is on the bench, so everything below comes from listening memory. That is a real limitation, but I’ve lived with the XONO for years and know how it presents my records. I expected the gap to be obvious, and it wasn’t. I found surprisingly little sonic difference.

I tested with records whose sound I know very well, mostly Prestige and Blue Note pressings from the golden era, many of them recorded by Rudy Van Gelder:

• Gene Ammons, Preachin’ (Prestige): The record that started this whole saga. Ammons’s tenor kept its warmth and body, and the rhythm section sat just where I remember it. The sax tone was intimate and precise, yet never overpowering.
• Sonny Rollins, Saxophone Colossus (Prestige): A good test of dynamics and Max Roach’s drumming. The drum attacks held up nicely compared to my memory of the XONO, though they may have been slightly less punchy.
• Art Blakey & The Jazz Messengers, Moanin’ (Blue Note): Lots of horn energy, plus crisp piano and brushwork. The front line sounded very lively, and I was swept up in the rhythm and the music without even noticing I was comparing gear.
• Lee Morgan, The Sidewinder (Blue Note): Punchy trumpet and a tight groove, with just the right bite in the horn.

Overall, tonal balance, timbre and energy came across much as I remembered.

If the XONO has an edge, it lies in the finest details, which is what I’d expect from a far more elaborate and expensive design. On some recordings, the XONO seemed to place instruments with more depth between the band members, for example on the track “The Prayer” (Gene Ammons / Preachin’). The difference is slight, though. For under €100, I find that remarkable.

A caveat, memory is a poor measuring instrument, and I’m comparing a unit I’ve owned for years with one I’ve had for days. A proper side-by-side test with level-matched gain will say more, and I plan to do one once the XONO is repaired.

Verdict

I would wholeheartedly recommend the Fosi X5, even to seasoned audiophiles. It never felt out of place in my system, and even without my XONO back for a direct comparison, it came much closer to my DIY reference than its price would suggest. It is also clearly better than my old first-generation Schiit Mani, although Schiit has released two newer iterations since, so that comparison is hard to judge in 2026.

One caveat: with no way to adjust loading or capacitance, the result depends on your cartridge. My Clearaudio Maestro V2 MM pairs very well with the X5, and I’ve heard from others that exotic MC cartridges such as the Hana SL work just as well. Your mileage may vary, but at this price the risk is tiny.

For around €100, do yourself a favour and just try it. The Fosi X5 may well turn out to be your end-game phono stage. It shows that you don’t need to spend a fortune on a RIAA preamp, even in a pricier system.