ЦАПы — FiiO K13 R2R

FiiO built the K13 R2R for the desk, combining an in-house resistor-ladder converter with a balanced headphone stage and a line output for active speakers or a power amplifier. It went on sale in September 2025 at USD 319, with black and silver versions offered.

Key specs that matter

FiiO designed its own four-channel, fully differential 24-bit R2R array for this unit, with 48 thin-film resistors per channel and 192 in total, each held to 0.1% tolerance and a temperature drift of 30 ppm. USB Type-C accepts PCM up to 32-bit/384 kHz and native DSD256 through an XMOS XU316 receiver, coaxial takes 24-bit/192 kHz and DSD64, optical handles 24-bit/192 kHz, and Bluetooth 5.4 supports LDAC, AAC and SBC. Headphones connect by a 6.35 mm single-ended jack or a 4.4 mm balanced jack, and the balanced output delivers 2,400 mW per channel into 32 ohm, or 600 mW per channel into 300 ohm, against 150 mW per channel from the single-ended jack at 300 ohm. From the balanced output FiiO quotes an SNR of at least 115 dB, THD+N below 0.0173% and output impedance under 1 ohm. The aluminium case measures 210 x 188 x 42 mm with feet and weighs 0.98 kg.

Engineering and use context

The signal stays fully differential from the resistor array through the low-pass filter and volume control to the headphone amplifier, which uses two OPA1642 and two TPA6120A chips from Texas Instruments. A NOS mode keeps the original sample rate, while the OS mode upsamples to the maximum rate before the ladder. A 10-band parametric EQ can be adjusted in the FiiO Control smartphone app or through a browser interface. Power comes from a built-in 30 W switching supply in a nickel-plated shield, or from an external 12 V, 2.5 A adapter, and is split across 18 low-noise LDO regulators and 5 DC-DC converters. A window in the top panel exposes the resistor array, the 1.1-inch LCD shows settings, an RGB logo changes colour with the sample rate, and an infrared remote, three gain levels, separate volume curves for line and headphone outputs and a 1 to 99 minute sleep timer complete the controls.

Pairing

As a preamplifier the K13 R2R feeds powered monitors or a stereo power amplifier through balanced XLR or single-ended RCA line outputs with its volume control active. The high balanced output drives planar headphones with low impedance and high-impedance dynamic models alike, and the lowest gain setting suits sensitive in-ear monitors.

Alternatives

The FiiO K11 R2R is a lower-powered desktop R2R DAC and headphone amplifier.