Fiio K11 R2R - Black - Silver

Description

Fully Differential R2R Desktop DAC/Amplifier
The FiiO K11 R2R represents a milestone in entry-level desktop HiFi design, outfitted with a self-developed true 24-bit fully differential R2R DAC, powerful amplification, and a meticulously engineered audio circuit. With NOS/OS dual operating modes, high-quality power regulation, and customizable display features, the K11 R2R provides an audiophile-grade listening experience in an elegant and compact form.

True 24-Bit R2R DAC Architecture
At its heart, the K11 R2R employs FiiO’s own four-channel fully differential R2R DAC, with each channel featuring 2×48 precision thin-film resistor arrays (192 resistors total). With 0.1% tolerance and 30ppm low temperature drift, this design drastically reduces distortion and FFT harmonics, producing exceptionally low noise and delivering a darker, purer background. Compared to typical DAC architectures, the fully differential R2R configuration enriches musical textures with a natural, charming timbre.

NOS and OS Dual Modes
The K11 R2R offers dual DAC operating modes:

1. NOS (Non-Oversampling) Mode: Maintains the original sampling rate for unaltered playback, presenting an organic and realistic sound character. 
    
2. OS (Oversampling) Mode: Upscales signals to 384kHz, enhancing detail for a crystal-clear presentation.

Supporting up to PCM 384kHz/32bit and DSD256, the K11 R2R effortlessly renders hi-res music with precision and depth.

High-Performance Volume Control and Gain
A NJW1195A 4-channel electronic volume controller ensures smooth, low-distortion adjustment across 3 gain levels with 3 independent volume curves, allowing optimized performance for everything from sensitive IEMs to high-impedance headphones. Combined with selectable output modes (PO/LO/PRE), the K11 R2R adapts seamlessly to any setup—headphone listening, preamplifier integration, or line-level output.

Specially-Designed Audio Circuit and Expanded Power Supply
The internal circuit routes digital audio through FPGA processing before decoding via the fully differential resistor ladder DAC. Output is filtered through precision OPA1642 op-amps, volume-controlled by the NJW1195A chip, and amplified with SGM8262 op-amps to deliver robust, balanced output.

Power delivery is handled by 17 precision LDO regulators, dual DC-DC converters, and a custom 12V external supply, feeding rail voltages from ±7.5V to 1.2V. Together with high-quality Beryl solid capacitors offering ultra-low ESR and high anti-interference, this ensures clean, stable power and exceptional audio purity.

Strong Output and Safety Systems
The K11 R2R provides up to 1300mW+1300mW (32Ω, balanced), capable of driving most modern HiFi headphones. An upgraded thermal design combines silicone gel with a precision aluminum body for effective heat dissipation, while shielding with phosphor-copper metal adds protection against external interference. Built-in protection includes DC output protection, pop noise elimination, overload safeguards, and intelligent power saving, ensuring both device safety and extended service life.

User Experience and Style
A custom LCD screen displays sampling rate, volume, and gain with clarity and durability, remaining always on without burn-in. The iconic RGB-illuminated FIIO logo is adjustable for brightness, color, and patterns, providing quick visual feedback on playback quality.
Control is centered around a multi-function volume knob, giving users intuitive control of menus, gain, volume, and switching between headphone and line outputs in a streamlined manner.

What’s in the box
FiiO K11 R2R unit
Power adapter
Power cable
USB data cable
Headphone adapter
Quick start guide