FiiO at Audio46


Product SKU: K3 New


Out of Stock

Currently unavailable to ship. See our form to sign-up to be notified when it's back in stock!

30 day Returns

Sometimes it's not meant to be. Let us know within 30 days.

Authorized U.S. Dealer

Having issues after 30 days? Comes with FiiO's 1 year limited warranty

 Earn 5% back in rewards! Learn More

This item is NOT eligible for promotional codes.
You may still earn and redeem Audio46 Rewards .

$109.99 Sale

zero units left

Email me when available

Email me when this product is in stock again

(Fun fact: By filling out this form, you let us know there's demand for this item!)

We will only send you a follow-up email once the product becomes available. Your email address will not be shared with anyone else.

Need help or product is sold out? Call (212) 354-6424, Chat or Email us

Product Details

(Specifications and appearance of this product are subject to change without notice)
↓ Details provided by FiiO

K3 Headphone Amplifier & USB-C DAC

Pocket-sized Power Flexibility

2 USB audio modes | PCM384k/DSD256 decoding |
Dual headphone outputs Dual digital audio outputs | ADC volume control

Boost your computer's sound with capable decoding

Equipped with an XMOS USB receiver chip, the K3 is capable of decoding up to 384kHz/32 bit PCM and native DSD256 – the same as many DACs costing much more. The K3's dual crystal oscillators ensure that any digital audio signal being fed into the DAC are exactly correct for further enhanced sound quality. Just connect the K3 to your computer via USB to instantly upgrade to high-fidelity sound, and enjoy your music the way it was meant to be heard.

Highly optimized architecture for maximum potential

The K3's well-thought-out internal design consists of two main layers, working  together perfectly in harmony. Digital processing is carried out by the high- performance AKM AK4452 with 32-bit VELVET SOUND technology and fully differential outputs for true balanced output, while the analog signals are handled and amplified by a design consisting of LPF/voltage amplification and a current drive circuit.

Wash away the noise with low-distortion op-amps 

The combination of the proven OPA926 with its low-distortion, low-noise, and high output swing along with the professional-grade TI OPA1612 acting as the low-pass  filter (LPF) ensures the K3 effortlessly provides highly resolving sound, pumping out 320mW at 16Ω from the balanced output.

Simply reliable USB power

The K3 adopts the modern USB Type-C input interface for a more reliable and stable connection, including that of power. However, care to ensure an uncompromised power supply doesn't stop there – the K3 implements overvoltage protection (OVP) and a double-filter circuit to ensure power supply stability, while the digital and analog audio circuits each get their own power supply to greatly reduce crosstalk.

No more channel imbalances with ADC volume control

The secret to effectively eliminating channel volume imbalances is to use an ADC volume control, which is implemented in the K3. Plus, an added side benefit is that by reconstructing the ADC curve, the user is able to smoothly adjust the volume to a more accurate and finer degree, allowing the K3 to be used with headphones of all kinds of sensitivity for a variety of listening needs.

Gain and bass switches to enhance your experience

The switch for high and low gain ensures that you  can use the K3 with a wide variety of headphones, and that your listening volume needs are covered. The hardware bass boost switch enhances the dynamic range of the lower frequencies and gives them some extra punch to really make your songs, games, and movies come to life.

Tiny round goodness in the palm of your hand

The all-aluminum black body has been painstakingly CNC-machined, anodized, and sandblasted to ensure that the K3 feels robust yet perfectly textured for a great feel in your hands. Combined with its small size, you  can easily take the K3 wherever you need to.

Two modes for many situations

Sometimes, you may not have access to a device that can connect to the K3 via USB  Audio Class 2. In these situations, you can go to USB Audio Class 1 mode with just  the flick of a switch.

For certain situations, you can use the 1.0 mode to enjoy up to 96kHz/24-bit PCM audio without needing any drivers.

In high-performance applications, you can use the 2.0 mode to enjoy up to 384kHz/DSD 256 decoding.

*Using the 2.0 mode requires downloading and installing the FiiO USB driver
*After switching USB modes, you need to either turn the K3 off and on, or unplug and plug in the USB cable.

A distinctly cohesive tactile audiovisual experience

The volume knob, with 45° notches etched onto its surface and perfectly sized to allow easy one-finger operation, is designed to perfectly blend in with the curves of the K3's body for a distinctive touch. Next to the volume knob is an RGB light that indicates what kind of digital audio is being input to the K3, visually confirming what you are hearing in your music.

Different connection options for different scenarios

1. Connect it to a desktop computer

2. Use the driverless 1.0 mode for business trips

3. Make it a digital turntable connected to an external decoder

4. Connect it to a speaker, using the K3 as a DAC

Dual headphone jacks

Being optimized for indoor desktop use, the K3 is equipped with both 3.5mm single-ended and 2.5mm balanced headphone jacks. Both outputs have audio jack detection, which means that when headphones are inserted into the balanced out, balanced boost automatically kicks in resulting in about a 50% output power increase compared to the single-ended out.

Line out connector

The 3.5mm line out is driven directly by the OPA1612 op-amp, to ensure as little sound quality reduction as possible. The line out output is also adjustable with maximum power output up to 2Vrms, to ensure compatibility with a wide variety of active speakers and external amplifiers.

*When using the line out, please disconnect any headphones

Coaxial and Optical digital outs

The XMOS USB receiver chip in the K3 directly converts any USB audio input to digital signals output via the coaxial and optical connectors, allowing you to connect to speaker systems, amplifiers, or other external decoders.

*The volume knob does not control digital output volume *The K3 can output digital audio signals up to 192kHz and DSD64 over DoP. Please adjust the settings of the device you are connecting the K3 to if the device does not support the digitally output format.


Model Name K3 Color Black
Weight 82g Dimensions 70×58×22mm
Volume Knob ADC Audio Input USB Type-C
USB Audio USB 1.0 / USB 2.0 USB Chip XMOS XUF208
Driver OP AMP OPA926×2 LPF OP AMP TI OPA1612
Gain Boost L/H Bass Boost 0/+6dB
Headphone Out 1 3.5mm single-ended output Headphone Out 2 2.5mm TRRS balanced output
Line Out 3.5mm Coaxial Out RCA for 192kHz, support DSD64 DOP
Optical Out Up to 96kHz Drive Ability 16-150 Ω
Output Power 1
(3.5mm headphone output)
220mW(16Ω); 120mW(32Ω) Output Power 2
(2.5mm headphone output)
320mW(16Ω); 200mW(32Ω)
Power Input Recommend DC5V 500mA Battery Capacity N/A
THD+N ≤0.004% Output Impedance <1.04 Ω
Frequency Response 20 Hz~80 kHz SNR >113 dB (A-weighted)
Line Level 1.9Vrms Crosstalk ≥70 dB (1 kHz)
MAX Output Voltage 7.39 Vp-p MAX Output Current 81.6 mA

Product Reviews



Your cart