FiiO S15 Silver

The FiiO S15 is a desktop Hi-Res audio streamer and DAC that sits at the top of FiiO's separates range, combining a flagship-grade digital-to-analogue converter with a full streaming platform into a single full-width chassis. It is designed for audiophiles who want a single source component capable of network streaming, local playback, and USB DAC duties, all processed through a premium analogue output stage.

Flagship DAC Architecture

At the heart of the S15 is an AKM dual-chip DAC combination pairing the AK4191 digital processor with the AK4499EX converter. This arrangement separates digital filtering from conversion, allowing each chip to operate in its optimal domain. The analogue output stage uses OPA1612 low-noise precision op-amps in the IV conversion and low-pass filter sections, and the entire signal path is fully balanced from input to output. Two ACCUSILICON AS318-B ultra-low phase noise femtosecond crystal oscillators -- one for 44.1kHz multiples, one for 48kHz -- govern clocking throughout, eliminating jitter at source.

Network Streaming and Android Platform

The S15 runs Android 12 on a Qualcomm Snapdragon 660 processor with 4GB RAM and 64GB internal storage, expandable to 2TB via microSD. This gives access to streaming services directly through their native Android applications, including Tidal, Qobuz, Spotify, Amazon Music and any other service available on Android. The unit supports AirPlay, DLNA, UPnP, SMB and WebDAV for network audio, and is Roon Ready certified. Wi-Fi covers both 2.4GHz and 5GHz bands, and a 100Mbps Ethernet port is provided for wired network connections.

Outputs and Connectivity

The S15 provides both balanced XLR and single-ended RCA analogue outputs, each in fixed-level and variable pre-amplifier configurations, giving four analogue output options in total. Maximum output levels are 8.9Vrms balanced and 4.5Vrms unbalanced in pre mode. Digital outputs cover optical, coaxial, AES/EBU, HDMI ARC and HDMI I2S. On the input side the unit accepts USB-C (for USB DAC operation), optical, coaxial, AES/EBU and HDMI, as well as Bluetooth 5.1 reception with support for LDAC, aptX Adaptive, aptX HD, aptX, aptX LL, AAC and SBC. Two USB-A ports allow connection of flash drives or portable hard disks for local playback.

Pure Music and Multiple Operating Modes

Beyond Android mode, the S15 offers a Pure Music mode that bypasses the Android layer for audiophile-grade playback, along with dedicated USB DAC, Bluetooth receiving, AirPlay, Roon Ready, optical, coaxial, AES and HDMI input modes. FiiO's DAPS (Digital Audio Purification System) enables non-resampled audio playback throughout, preserving the original sample rate of each source. A 10-band high-precision parametric EQ with plus or minus 12dB adjustment per band and an All-to-DSD conversion option are also available.

Build and Control

The S15 occupies a standard 430mm-wide equipment rack width and is constructed from an all-metal body with a 7.84-inch full-colour touchscreen display running a custom landscape interface. A front-panel volume control knob incorporates a codec and sample rate indicator light. A Bluetooth remote control and companion mobile app provide additional control options. The unit is powered by a 35W low-noise linear power supply with four 4700uF ELNA capacitors.

The S15 won the EISA Best Product Award for 2025-2026 in the Hi-Fi Component Streamer category.