FiiO has expanded its desktop audio lineup with the K17 R2R, a combined DAC, network streamer and headphone amplifier that places the company’s own resistor-ladder conversion stage at the center of a full-featured hi-fi hub.
A desktop hub with FiiO’s R2R PRO conversion
The defining change in the K17 R2R is its digital-to-analog section. FiiO uses its proprietary segmented R2R PRO resistor matrix, specified at 24+5 bits, replacing the DAC architecture while retaining the broader K17 hardware platform.
For the upper five bits, the design uses 31 resistors with thermometer coding. FiiO’s stated aim for this approach is to reduce error accumulation compared with a conventional R2R ladder arrangement. The result is a version of the K17 intended for listeners who want FiiO’s take on discrete-style ladder conversion within a modern desktop component.
The chassis combines an aluminum body with real wood side panels. The silver version is paired with white ash, while the black finish uses walnut, giving the unit a more furniture-like appearance than a typical all-metal desktop DAC.
Discrete class AB headphone amplification
Beyond conversion, the K17 R2R includes a fully discrete headphone amplifier operating in class AB. Its amplifier stage uses an op-amp-based circuit with transistor current amplification built around ON Semiconductor MJE243G and MJE253G devices.
FiiO specifies the balanced headphone output power at not less than 4000 mW + 4000 mW into 32 ohms with THD+N below 1%. The company also cites low output impedance, positioning the unit for a range of headphone loads.
The analog architecture is described as fully differential from the DAC through I/V conversion and low-pass filtering to the headphone amplifier. Texas Instruments low-noise precision operational amplifiers are used in these analog stages.
Headphone and line-level connections
The front panel covers the main headphone formats expected from a desktop headphone amplifier. Users get a 6.35 mm unbalanced output, a 4.4 mm balanced output and a four-pin XLR balanced output.
For integration with external hi-fi systems, the K17 R2R provides RCA and XLR line outputs. It also includes analog line inputs on RCA and balanced XLR, allowing it to function as more than a USB DAC or network playback device.
Digital inputs include USB, coaxial and optical. This gives the unit compatibility with computers, transports and other digital sources, while the analog inputs allow separate source components to be routed through the same control and amplification platform.
Network streaming, local playback and Bluetooth
The K17 R2R supports Roon Ready operation, AirPlay, QPlay and NAS playback. Network connectivity is handled via Gigabit Ethernet or dual-band Wi-Fi on 2.4 GHz and 5 GHz bands.
For home library access, the device supports SMB and NFS, enabling playback from network storage. It can also work as a USB DAC, coaxial DAC, optical DAC, Bluetooth receiver, or play music locally from a USB storage device.
Bluetooth 5.1 is included with support for SBC, AAC, aptX, aptX LL, aptX HD, aptX Adaptive and LDAC codecs. That codec list gives the K17 R2R a broad wireless compatibility set alongside its wired and network playback options.
Control options and equalization
FiiO provides several ways to operate the K17 R2R. Volume and mode changes can be made using the physical controls on the chassis, the 3.93-inch touchscreen, the supplied infrared remote control or the FiiO Control app.
The unit includes a 31-band lossless PEQ and AUTO EQ. Equalizer and device settings can be adjusted through FiiO Control, which is also used for saving and loading profiles.
Taken together, the control system reflects the K17 R2R’s role as a desktop centerpiece rather than a single-purpose converter. It is designed to manage local, network, wireless, digital and analog sources from one chassis.
The FiiO K17 R2R brings a ladder-DAC version of the K17 concept to desktop listeners, combining R2R conversion, network audio, Bluetooth, extensive wired connectivity and a high-power balanced headphone amplifier in two wood-trimmed finishes.
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