FiiO is an audio brand with a wide range of portable and desktop products and its latest release is the brand-new K13 R2R. This desktop DAC and headphone amplifier uses the latest discrete resistor ladder decoding technology with an ultra-low noise architecture and desktop-class driving power.
FiiO says the K13 R2R serves up “flagship sound quality” in a compact, versatile and future-proof unit. It even has a window on its top-plate showing so users can see the full configuration of chipsets used.
Offering what FiiO describes as “a true hi-fi sound for your laptop, tablet or phone,” the K13 R2R can be used on a desk, a bedside table or in an existing hi-fi set up. Users can also add the FiiO DM13 CD player and SP5 speakers to build a full hi-fi system.
Discrete R2R
At the heart of the K13 R2R is a fully discrete resistor ladder DAC. Made of an array of precision resistors configured for true multibit conversion. FiiO says the R2R’s decoding delivers a more natural and organic sound.
The K13 R2R’s resistor network is paired with FiiO’s proprietary error-correction algorithm for precise matching, linearity and ultra-low distortion. FiiO claims the result is a sonic presentation that combines technical accuracy with a sense of warmth and a natural flow that’s good for analytical listening as well as long musical sessions.
To fully unlock the potential of the discrete R2R ladder, the K13 R2R brings together an FPGA + DSP system that takes care of the digital signal processing, clocking and oversampling. The unit can handle audio files up to PCM 1536 kHz and DSD1024, for full compatibility with the latest hi-res formats.
With 2,400mW of power, the device has enough headroom to drive everything from a sensitive pair of IEMs all the way up to a demanding pair of planar magnetic headphones with complete control.
Selectable gain levels enable users to fine-tune the output for different types of headphones, ensuring quiet backgrounds for sensitive monitors as well as sufficient muscle for driving a pair of 600Ω headphones.
Connectivity
When it comes to connectivity, the K13 R2R has a choice of Balanced XLR and 4.4mm headphone outputs. It also has a single-ended 6.35mm headphone jack as well as balanced and single-ended line outs for driving a pair of active monitors such as the FiiO SP5 or external amplifiers.
FiiO claims that it’s this level of flexibility that can turn the K13 R2R into the centerpiece of a desktop or home audio setup, running anything from a minimalist headphone set up to full-on audiophile system.
With the K13 R2R, FiiO has created a DAC and a platform. Equipped with XMOS XU316 USB receiver, the device supports USB, optical, coaxial, and I2S inputs, making it compatible with PCs, streamers, CD transports and more. There is an OLED display with intuitive UI for control of input selection, gain, filters and output modes.
Audiophile Standard
Low-noise LDO regulators and dual-independent power supplies used in the K13 R2R provide both isolation and stability while premium film capacitors and precision resistors are there to deliver consistency in the R2R ladder.
The unit is housed in an all-aluminum chassis with precision CNC machining to provide both durability and efficient heat dissipation. The knurled volume knob has been engineered for precise and tactile control.
Despite its innovative internals, FiiO says it has designed the K13 R2R with usability in mind. It’s display and intuitive menu system offer instant feedback on input, sample rate and filter settings. There is a full suite of digital filters for anything from a smooth roll-off for relaxed listening to sharp filters for maximum accuracy.
The FiiO app can be used to control the unit and it also provides access to Parametric EQ for creating personal sound profiles.
Pricing and Availability:
The FiiO K13 R2R will be available through authorized retailers in September 2025 at £279, $319, €319. Pre order at Advanced MP3.
Tech Specs:
- Color: Black, Silver
- Main control chip (MCU): ESP32-S3
- USB chip: XMOS XU316
- DAC: Fully differential true 24Bit R2R DAC resistor arrays
- Volume control chip: NJW1195AV
- R2R and LPF op-amp: OPA1642 x 4
- LO buffer op-amp: LTA8092 x 2
- Headphone amplifier: OPA1642 x 2+TPA6120A x 2
- USB input: 384kHz/32-bit, DSD256.
- Coaxial input: 192kHz/24bit, DSD64.
- Optical input: 96kHz/24-bit.
- USB connector: Dual Type-C.
- Bluetooth 5.4.
- Display: Custom LCD.
- Power input: AC 100-240V 50/60Hz; DC 12V/2.5A.
- Dimensions: About 210 x 188 x 42mm (including feet).
- Weight: 980g.
- Single-ended power output 1: L+R≥1220mW +1220mW (32Ω, THD+N＜1%) (32Ω/SE/high gain).
- Single-ended power output 2: L+R≥150mW+150mW (300Ω, THD+N＜1%) (300Ω/SE/high gain).
- Balanced power output 1: L+R≥2400mW+2400mW (32Ω, THD+N＜1%) (32Ω/balanced/high gain).
- Balanced power output 2: L+R≥600mW+600mW (300Ω, THD+N＜1%) (300Ω/balanced/high gain).
- Frequency response: 20Hz~80kHz: Attenuation＜2.9dB
- SNR: ≥116dB (A-weighted).
- Noise floor: PO＜9uV (A-weighted); BAL＜18uV (A-weighted)
- Output impedance: PO＜0.7Ω (32Ω load); BAL＜1Ω (32Ω load)
- THD+N: About 0.0173% (1kHz/-6dB@32Ω).
