Is that really a streamer or a preamp with streaming capabilities?
I’d like to share a few thoughts on Fosi Audio S3 Streamer
The Fosi Audio S3 is an ambitious all-in-one streaming component that combines a network streamer, DAC, and preamplifier in a compact chassis. Designed to serve as the digital heart of a modern Hi-Fi system, the S3 focuses on flexibility, balanced audio performance, and seamless wireless streaming.
One of the most appealing aspects of the S3 is its connectivity and streaming capability. With dual-band Wi-Fi 6 and Bluetooth 5.3, the unit provides stable and fast wireless audio transmission. It supports popular streaming protocols such as Spotify Connect, TIDAL Connect, AirPlay 2, and Google Cast, allowing users to stream music directly from their favorite apps. The device also supports playback from local network storage (NAS), making it suitable for listeners who maintain their own digital music libraries.
At the heart of the S3 is the AKM AK4493SEQ DAC, paired with OPA1612 op-amps in a balanced circuit design. This combination is known for delivering a clean, detailed sound signature. The specifications are impressive for the price category, with THD+N as low as 0.00018% and signal-to-noise ratio up to 120 dB, suggesting a very quiet background and accurate signal reproduction. The balanced XLR outputs further enhance performance when connected to balanced amplifiers, potentially offering better channel separation and improved noise rejection.
The S3 also functions as a digital preamp, allowing it to directly control power amplifiers or active speakers. This flexibility simplifies system design, especially for minimalist setups. In addition to analog outputs, the device provides multiple digital connections and features HDMI eARC, which makes it easy to integrate with a television for a simple 2.1 home theater system when paired with a subwoofer.
Ease of use is another strong point. The Fosi Audio mobile app provides straightforward control over playback and system settings. A built-in 5-band equalizer allows users to fine-tune the sound to their taste. Multi-room playback via AirPlay 2 or Google Cast also enables synchronized music throughout the house if multiple S3 units are used.
From a design perspective, the S3 follows Fosi’s typical approach: compact, clean, and practical. Thermal management, trigger control for system power synchronization, and built-in protection circuits all contribute to reliable operation in everyday use.
Overall, the Fosi Audio S3 stands out as a versatile and well-equipped streamer for modern audio systems. By combining streaming, DAC, and preamp functionality in one unit—and including balanced outputs and high-quality DAC architecture—it aims to deliver serious Hi-Fi performance at a relatively accessible price point. For listeners looking to build a streamlined digital front end without sacrificing sound quality, the S3 appears to be a compelling option.
In my system, I connect WiiM Ultra as transport with Optical output to Fosi S3. CD player connects to S3 with RCA, and from the S3 to my amplifier. This setup allows me to experience three different DAC configurations. Each configuration produces noticeably different sonic characteristics.
Using the WiiM Ultra alone connected directly to my preamplifier, the sound is very clear, clean, and transparent, with excellent detail retrieval. The soundstage is precise and well focused, but the overall presentation can feel slightly thin, with lighter bass weight and a somewhat lean tonal balance.
When I connect the WiiM Ultra to the Fosi Audio S3 and use the S3’s AKM DAC, the sound are still clear and clean but also more natural and balanced. The midrange gains a little more body, and instruments such as piano and vocals sound more lifelike. The soundstage also feels slightly wider and more relaxed, while bass notes have better weight and smoothness. I personally love this configuration the most.
Using the Fosi Audio S3 by itself as the streamer and DAC produces a very natural and musical presentation. The tonal balance is slightly warmer and smoother, with a pleasing midrange that works especially well for vocals and acoustic instruments. While the ultimate level of transparency may be slightly lower than the WiiM Ultra alone, the S3 delivers a more organic and comfortable listening experience, making long listening sessions very enjoyable.
Overall, each configuration offers its own strengths, and the ability to experiment with different signal paths makes the system both flexible and engaging.
Overall, the Fosi Audio S3 proves to be a surprisingly capable and flexible digital front end. Its ability to handle multiple input sources and streaming services including Apple AirPlay 2, while offering a smooth, natural sonic character makes it a very enjoyable component in a modern audio system. In comparison, the WiiM Ultra excels in clarity and transparency, but pairing it with the S3’s AKM DAC introduces a fuller and more organic presentation that many listeners may prefer for long listening sessions. The S3 may not chase extreme analytical detail, but it delivers a balanced, musical sound that works well across many genres. For listeners who value versatility, ease of use, and a natural tonal balance, the Fosi S3 is a compelling addition to a streaming-based Hi-Fi system.
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