Closer Examination

The FiiO K19 is a desktop class DAC/headphone amplifier all-in-one device, akin to some others we have seen before from FiiO. But that is where the similarities end, with the K19 adopting a different form factor, and indeed preferred orientation, compared to the behemoth K9/K9 AKM/K9 Pro ESS units also being sold alongside. Those were bulky and heavy compared to the K19 which is longer but comes off petite instead, at 250 x 225 x 36.7 mm while weighing ~1.8 kg. This is made possible with the use of a die-cast unibody aluminium alloy that is designed to be shock-proof and gets polished by a multi-axis CNC machine to look fancier than just the industrial aesthetic FiiO went for before. It comes in black or silver color options with plenty of ventilation to aid in passive cooling. FiiO says it initially planned to have transparent glass where the honeycomb mesh currently is but decided it was going to compromise on cooling and performance more than it felt comfortable with. The end result is what we see above, with FiiO branding on the top—if used horizontally—with three headphone outputs on the front in the form of a 4-pin XLR and 4.4 mm for balanced connections, as well as a single-ended 6.35 mm (1/4") out. There's also a 1.3" TFT LCD color display (240 x 240 pixels) similar to what we have seen in the FiiO Q7 before. I also appreciate the easily accessible USB Type-C input right here for people to connect their mobile devices, say. Next up are two rotary knobs with one handling power/volume and the other being a menu selector. These are small compared to the large, single volume wheel on the K9 series and the accompanying writing also suggests how the K19 is intended to be used vertically, with indicator light rings around them.


A look from the side shows even more ventilation, with FiiO taking the passive cooling seriously. In fact, the outer chassis is part of a heatsink-based cooling system wherein the relevant components inside have heatsinks/thermal pads to help transfer heat outside. The form factor of the K19 also allows for more I/O options on the back including, for the first time in FiiO's desktop DAC/amp product line, HDMI 1.4/2.0 in as well as HDMI 1.4/2.0 out with ARC capability allowing the K19 to be part of a proper home media setup. Additionally, we see a bidirectional 12 V trigger allowing you to sync compatible devices and turn them on/off together. A ground/lift switch underneath can help reduce device interference and crosstalk too. FiiO has moved away from USB Type-B in favor of Type-C inputs only, including one dedicated for data as an RS-232 port. There's also Bluetooth input as well as coax and optical in/out and analog RCA and dual 3-pin XLR outputs as expected, although an I2S input would have been nice to see here. Those who prefer to use an external clock are also out of luck here as we end things with power inputs in the form of DC or AC with a switch choosing between the two and a tiny switch turning the device on or off. We don't see a voltage selector switch as before on the K9 series, but this is because the K19 is now more compatible with different operating voltages around the world.


I am thankful that FiiO has decided to leave all other branding and certification stickers on the bottom, although this will be a visible side if used vertically. Here too we see more of the same honeycomb style mesh and there is a finer mesh screen underneath too. The corners are where you will install the provided rubber feet if using the K19 horizontally. I suspect most will go vertical though and this is where you will need to find a sticker on the side alerting you about two sets of screw threads that you use with the metal feet, screws, and screwdriver also provided in the box. The end result is a stable base allowing the K19 to rest vertically and take a lot less room on your desk. There is also a side benefit of going this route if you use the provided headphones stand accessory which simply gets pushed in place at the top, and now you can rest your favorite headphones on it as seen above. This does block some of the vents, but I have not noticed any cooling deficits causing performance issues.


Disassembly of the FiiO K19 is not trivial because of the unibody construction and the screws securing the chassis to the internals are underneath the mesh screens on either side. FiiO says it will publish a video showing how to disassemble the K19 for anyone interested, but in the meantime I have to go by the brand's own images to discuss what is making the K19 tick. We see the digital and analog sections, including their individual power supplies, are on completely different PCBs on different sides of the chassis to help with isolation and reduce any potential interference. There's plenty of shielding too with the mesh screen also aiding in this. As expected from a flagship device, the FiiO K19 uses two flagship ESS Sabre ES9039PRO 32-bit 8-channel DACs. More exciting is a dedicated SoC for digital signal processing (DSP) using the Analog Devices SHARC+ core, thus making the K19 far more than just another device using an XMOS encoder, although we still get an XMOS XU316 USB bridge for desktop users and a Qualcomm QCC5125 for Bluetooth support. Amplification is fully balanced courtesy an 8-channel THX AAA 788+ linear op-amp setup. All these provide excellent numbers for those prioritizing source measurements as seen on the spec sheet and will no doubt be independently verified by others soon.