The FiiO K13 R2R features a fully differential volume control system and headphone amplifier which means minimal distortion, excellent interference rejection and dynamic range that remains intact throughout the chain.
Specifications:
Main control chip (MCU): ESP32-S3
USB chip: XMOS XU316
DAC: Fully differential true 24-bit R2R DAC resistor arrays
Volume control chip: NJW1195A
R2R and LPF operational amplifier: OPA1642 ×4
Input power: AC 100–240V 50/60Hz; DC 12V/2.5A
Enter and exit:
USB input: 384kHz/32bit, DSD256
Coaxial input: 192kHz/24bit, DSD64
Optical input: 96kHz/24bit
USB port: Dual Type-C
Physical characteristics:
Dimensions: ~210 × 188 × 42 mm
Weight: ~980 g
Output power (single)
L+R ≥ 1220 mW + 1220 mW (32 Ω, THD+N<1%, SE, high gain)
L+R ≥ 150 mW + 150 mW (300 Ω, THD+N<1%, SE, high gain)
Output power (balanced)
L+R ≥ 2400 mW + 2400 mW (32 Ω, THD+N<1%, balanced, high gain)
L+R ≥ 600 mW + 600 mW (300 Ω, THD+N<1%, balanced, high gain)
Frequency response: 20 Hz–80 kHz, attenuation <2.9 dB
SNR: ≥116 dB (A-weighted)
Output impedance:
PO <0.7 Ω (32 Ω load)
BAL <1 Ω (32 Ω load)
THD+N: ~0.0173% (1 kHz / –6 dB @32 Ω)
HR 
SL 
EN