Fosi S3 Streamer/DAC/pre

https://youtu.be/I_AnXrt44t8

Missing from Fosi‘s catalog, without a doubt, was a streamer, and many people-including us-wondered when and if the manufacturer would venture into increasingly rough terrain, given the wide competition ranging from the inexpensive WiiMs, which we have tested far and wide, to Bluesound or Marantz, to name but two. But what does the name Fosi mean? Foresight, Openness, Sincerity and Innovation, meaning vision, openness, sincerity and innovation. The company is relatively young in the hi-fi scene, but its growth has been extremely rapid and significant. Founded in Shenzhen in 2017 by Ryan Huang, it was born with a very clear goal: to make high fidelity accessible to a much wider audience than the mainstream-a mission common to many of these emerging companies. The brand story starts in an almost artisanal way, in a very small space, with a strong focus on value for money and direct online sales. First compact class-D amplifiers and small desktop devices, which allowed it to emerge quickly in the global market, especially thanks to distribution on platforms such as Amazon; then the turning point in 2019 with the increase of models in the catalog and in particular the BT20A, which has been a huge commercial success.

Hence the decision to gradually expand the catalog, introducing DACs, preamplifiers, and headphone amplifiers, while developing a strongly user-oriented model, gathering feedback from the community to directly influence the design and features of new products. Today Fosi Audio is considered one of the most dynamic emerging players in the entry-level hi-fi industry, with global distribution covering more than 100 countries. The Fosi S3 could not be missing from the catalog. Fosi Audio is now well known for its amplifiers, but it needed to address the more complex segment of today’s hi-fi, where it is no longer enough to “sound good,” but to also offer a user experience that is up to par. The S3 is a streamer/preamplifier with built-in DAC: a good first step, no doubt, but with some critical issues.

Excellent hardware

In terms of construction, the S3 features the classic Fosi design: small size, metal supporting structure, understated finish, and a certain solidity that, in relation to the price, continues to be one of the strong points of the manufacturer’s production. The form factor clearly recalls that of the brand’s most popular amplifiers, thanks in part to the unmistakable orange aluminum knob, but it does not replicate it consistently. The proportions are slightly different, the footprint does not, for example, match the ZA3-with which it can be purchased as a bundle-and this makes it difficult, almost enigmatic, to place side by side or stack neatly with other Fosi components. Even less convincing is the handling of the front interface. The minimized system of small LEDs is unreadable and requires some familiarity to interpret correctly. In normal lighting conditions it can be almost invisible and, during daily use, ends up making it less immediate to understand the status of the device.

Nothing to say on a strictly technical level: the S3 is extremely complete, as is the Fosi tradition. Network streamer, DAC and preamplifier with excludable volume control in one chassis make it extremely versatile. Connection possibilities are extensive and include both traditional digital (optical) and HDMI eARC inputs, making the device usable in mixed settings between hi-fi and television. There is an optical output for an external DAC, an RCA IN for any analog source, as well as a subwoofer out that is not filtered, however: convenient for connection, but relatively unhelpful. Compatibility with services such as Roon, Tidal Connect, Qobuz Connect, Spotify Connect and AirPlay 2 provides maximum flexibility, which also extends to files: PCM up to 32/768 and native DSD64 and DSD128, with a software update downloaded the day we shot the video.

Where the limitations of a still young project are felt, however, is in the software component. The proprietary app does its job and is also available through the browser by pointing to the IP address, but it remains relatively undeveloped. The interface is simple, the essential functions are there, but it lacks that feeling of completeness found in many competitors. This is not-let’s be clear-an unusable or slow app, far from it; however, it is clear that there is ample room for improvement. Useful features include a fairly accurate 11-band equalizer, with no presets: available only flat or inserted. Added to this is the absence of features that are now becoming almost standard, such as multi-room management and room correction systems. The S3 thus remains a device designed for single, traditional listening, with no ambitions for advanced integration within the home. It is also true, however, that many streamer manufacturers are making a different choice: since there are Connect apps, which manage the device directly, a proprietary app seems entirely superfluous, destined to go unused.

Listening, a big surprise

Thanks to the fact that we participated in the development of the product, the S3 has been used in many different systems, even those far above its segment level. This has not been a purely theoretical exercise: each listening has helped to return an increasingly clear picture of the true potential of this DAC/streamer, beyond what the list price might suggest. The S3 is equipped with XLR and RCA outputs, but it is inherently balanced: to express itself at its best it needs equally balanced amplification, and in its price segment there are almost none, except at Fosi. This detail is not secondary: the balanced topology ensures better rejection of common noise and sharper channel separation. It is precisely this feature that made it permissible-and in some ways inevitable-to test it on chains of quite different stature. It therefore came naturally to us to connect it and listen to it with some excellent amplifications transitedthrough the listening room, from Vitus up to Luxman, via Canor. Pairings that under normal conditions would seem out of context, but actually had the merit of eliminating any disturbing variable from the chain, allowing us to precisely isolate the S3’s sonic contribution. We also conducted a further test, replacing the supplied plug-in power supply with a high-end linear power supply-specifically a Keces, which was certainly oversized compared to the S3. That was what we had available at the time, and curiosity was high. However, experience confirmed to us how a power supply upgrade, even with less expensive but still refined products – such as iFi power supplies or some linear ones that can be purchased on Aliexpress – can significantly improve the S3’s audio performance.

The results, let’s be clear, surprised even us. The S3 is clean, free of coloration, with a well-centered tonal balance. It does not try to please first impressions through timbral shortcuts, does not artificially emphasize either low or high frequencies to create an immediately spectacular effect. Its sound is honest, and this honesty-which at first distracted listening might even sound like cold neutrality-turns out instead to be an uncommon virtue, especially in this price range. The low end is controlled, dry, and maintains good articulation even on complex passages, such as electric bass lines or jazz double bass. The low register does not overflow, does not swell, does not try to impress with a semblance of weight that does not belong on the recording. On a tune like Miles Davis’ So What, Paul Chambers’ double bass maintains its rhythmic identity without turning into a shapeless mass; the same precision is found on more modern material, where the synthetic bass tends to challenge less rigorous components. There is not that feeling of artificial warmth or excessive contrast typical of many inexpensive devices, which also manage to be seductive in the first few minutes of listening, only to reveal their nature as time passes. The midrange is equally convincing. Voices emerge naturally, are never too forward and maintain good intelligibility even at low volumes. This is especially appreciated in evening sessions at lower sound levels, where many devices betray some loss of coherence and presence. The S3, on the other hand, retains its linearity even when not pushed: voices-both male and female-preserve body and definition without requiring compensation in volume. On acoustic recordings, such as small jazz ensembles or chamber music, the S3 returns a credible soundstage, with instrument separation far superior to its price category. The soundstage has its own spatial logic: instruments occupy stable positions, not floating, and the depth of the soundstage is convincing enough to distinguish planes. On a string quartet, for example, it is possible to clearly perceive the difference in distance between the two violins and the cello, without everything collapsing into a two-dimensional plane. We are not at the levels of a top-class product, of course, but the result is surprising for a component in this range.

Surprising, with few reservations

Thus, it remains a product with a dual nature. On the one hand, a solid hardware base, sound quality that exceeds expectations, and versatility that makes it suitable for many uses. On the other, a number of limitations that mainly affect the user experience: the form factor inconsistent with the rest of the Fosi range, the unreadable front LED system, the absence of multi-room and room correction, and a still immature app. The result is a streamer/DAC/pre that represents an excellent entry point into the world of hi-fi streaming, capable of offering high-level performance at an affordable price, but also hinting at how much room there still is for full maturation of the design.

Technical characteristics:

• Chipset: Amlogic A113X, AKM 4493SEQ, OPA1612
• Network: 802.11 a/b/g/n/ac/ax dual-band Wi-Fi (2.4 GHz and 5 GHz) 10/100M Ethernet
• Bluetooth: Bluetooth 5.3, A2DP, AVRCP, BTLE; supports SBC and AAC codecs
• Sampling Rate: 32/384, DSD128
• Streaming protocols: Google Cast, AirPlay 2, DLNA, Roon Ready, Spotify Connect, Tidal Connect, Qobuz Connect
• Dimensions: 17.3X17.3X4.7

Manufacturer: Fosi Audio

Distributor: Fosi Audio, Amazon

To buy S3 click here