FiiO K13 R2R combines a true 24-bit R2R DAC, powerful balanced headphone amplification, Bluetooth reception, PEQ, and preamplifier functionality in one versatile desktop audio center.

FiiO’s proprietary four-channel R2R DAC uses 192 precision thin-film resistors with 0.1% accuracy and 30ppm low temperature drift, delivering a rich, natural, and musical presentation.

Why it stands out

True 24-bit R2R conversion

FIIO’s four-channel fully differential resistor-ladder DAC uses 192 precision thin-film resistors, giving listeners a genuine R2R alternative to conventional delta-sigma desktop DACs.

NOS and OS playback modes

Switch between non-oversampling and oversampling playback instead of being locked into one presentation. NOS prioritizes the direct R2R signal path, while OS applies digital oversampling for a different response.

Strong balanced headphone amplification

The 4.4mm balanced output delivers up to 2400mW + 2400mW at 32Ω in high gain, while the 6.35mm output supports conventional single-ended headphones.

One hub for digital sources and stereo systems

Connect computers, phones, televisions and digital transports through USB-C, Bluetooth 5.4, optical or coaxial input, then listen through headphones or feed an amplifier or active speakers through RCA or balanced XLR.

Best for

• Desktop R2R listening with headphones
• Balanced stereo systems requiring XLR output
• Users who want Bluetooth plus USB and S/PDIF inputs

Not ideal for

• Portable or battery-powered listening
• Users requiring analog audio input
• Driving passive speakers directly

EMiUZEK Buying Notes

• K13 R2R accepts digital sources only; it has no RCA or XLR analog input for a turntable, cassette deck or other analog source.
• Bluetooth works as a receiver for audio from a phone, tablet or computer. It does not transmit audio to Bluetooth headphones or speakers.
• RCA and XLR are line or preamplifier outputs for an amplifier or active speakers; they cannot power passive speakers directly.
• The quoted 2400mW + 2400mW output is for the 4.4mm balanced connection at 32Ω in high gain. Start with low volume and choose gain according to the headphones being used.

FAQ

How should I choose between NOS and OS mode?

NOS plays through the R2R ladder without digital oversampling and is the mode to try when you want the most direct R2R presentation. OS applies oversampling and may suit listeners who prefer a smoother, more controlled presentation. Neither mode is universally better, so you can switch between them without changing the rest of the system.

Do I need a balanced headphone cable to use the K13 R2R?

No. Headphones with a standard 6.35mm plug can use the single-ended output. The 4.4mm connection is for headphones wired for balanced operation and is required to access the highest quoted output power. Do not connect a single-ended plug through an unsafe balanced adapter.

Can the K13 R2R be used with an amplifier or active speakers?

Yes. Use the RCA output for a conventional stereo connection or XLR for a balanced connection. Select the appropriate line or preamplifier mode for the receiving equipment. Passive speakers still need a separate amplifier because the K13 R2R is not a speaker power amplifier.

What sources can I connect, and what does Bluetooth not do?

Computers and compatible phones can use USB-C; televisions and digital transports can use optical or coaxial output; phones, tablets and computers can stream to the unit through Bluetooth 5.4 with SBC, AAC or LDAC. Bluetooth is receive-only, and there is no analog audio input.

HOW TO CONNECT

Computer and wired headphones

Source icon: Computer
Source: PC / Mac
Connection: USB-C
Output connection: Headphone output
Target icon: Headphones
Output: 6.35mm / 4.4mm

Note: Select USB input, choose a suitable gain level and begin with the volume low.

Phone or tablet and wired headphones

Source icon: Phone
Source: Phone / tablet
Connection: Bluetooth
Output connection: Headphone output
Target icon: Headphones
Output: 6.35mm / 4.4mm

Note: The phone sends audio wirelessly to the K13 R2R, but the headphones remain wired.

TV or digital source to a stereo system

Source icon: TV
Source: TV / digital transport
Connection: Optical / coaxial / USB-C / Bluetooth
Output connection: RCA / XLR
Target icon: Amplifier or active speakers
Output: Line output / preamplifier output

Note: For television use, select PCM digital output. Passive speakers require a separate amplifier.

Technical Specifications

Feature	Specification
Product type	Desktop R2R DAC and headphone amplifier
DAC	FIIO-developed four-channel fully differential 24-bit R2R
USB controller	XMOS XU316
Amplifier	2 × OPA1642 + 2 × TPA6120A
Bluetooth	5.4; SBC, AAC and LDAC
Digital inputs	2 × USB-C, optical and coaxial
Headphone outputs	6.35mm single-ended and 4.4mm balanced
Line outputs	Stereo RCA and balanced XLR
Maximum USB decoding	PCM 384kHz/32-bit; native DSD256
Balanced power	≥2400mW + 2400mW at 32Ω
Dimensions	Approx. 210 × 188 × 42mm
Weight	Approx. 980g
Power	AC 100–240V or DC 12V/≥2.5A

What's in the box, manuals and downloads

Refer to the current FIIO K13 R2R regional packing list. Use the EMiUZEK download center or FIIO support center for manuals and firmware.