Article Index
FiiO X7
p3 Sound Quality
p4 Conclusion
p5 Measured Performance
All Pages


The player has wi-fi that, FiiO say, facilitates auto-updating, but in our early sample player this did not work and it had to be manually updated. 

The Pure Music mode interface was usable but needed clarification by use of colour in Settings category headlines, for example; its monochromatic nature was neither attractive nor helpful. 

FiiO provide few sound options, Low or High gain (meaning output), Gapless playback, Line/Coax. A 10 band equaliser is available, but only during track play; it has eight presets and a user definable mode. Info/option screens can be slid in from bottom, left and top, with a finger swipe. 

Storage comprises 32GB of on-board memory, that contains Android OS support files, plus a music files folder. You only see the latter in Pure Music mode; you see them all when uploading via USB from a computer. Additionally, there is one microSD card slot that will address 128GB maximum; a card is not supplied.

Like Astell&Kern players, but unlike FiiO’s less expensive players, the X7 has a touch screen, eliminating the rotating selector and offering more screen area. Overall, however, I did not find the X7 easier to understand or use. I am no fan of gratuitous complexity and Android moves the X7 toward a mobile phone-type user interface, with lots of bells and whistles – and my pockets and home already have plenty of these, with clocks, apps., accelerometers, web browsers etc. popping up all over. I may be in a minority here by not being wowed by this stuff – and it is why I like the straightforward simplicity of FiiO’s less grandiose players.



The Settings menu is poorly delineated by same-colour category headers.



The touch screen controls are duplicated on the right side by a transport control and there’s a volume control at left, comprising Up/Down buttons. Start up is a not so fast at 28 seconds, from what FiiO proudly describe as a Rockchip RK3188 CPU. However, more interesting because of its direct relevance to sound quality, was their use of an ES9018S DAC chip in the X7, from the renowned Sabre32 series produced by ESS of California. With four of its eight channels paralleled per stereo side this offers, potentially, 123dB Dynamic range, and most manufacturers (e.g. Audiolab) achieve 120-122dB our measurements show. 

However, in conjunction with an OPA1612 acting as current-to-voltage convertor, and one as a low pass filter, plus OPA1612 feeding an AD8397 headphone driver in the AM1 module, FiiO achieve 117dB dynamic range from the X7 our measurements showed, 5dB below what is possible. All the same, as portables go, this is a good performance – ignoring the 125dB achieved by Chord’s Mojo. 

I must quickly mention that our review sample had early FW1.0 firmware and it would not update automatically over wi-fi from FiiO’s website, as claimed, nor would it update manually from a file downloaded onto a Mac (OSX 10.11.3). Macs automatically unbundle zip files so FW1.8 had to be re-compressed, but still no joy. In the past hidden Mac desktop files were the cause of this problem but these days Mac-zipped files usually run. The X7 only updated from a PC (Windows 7) download, I found, saved straight to the X7’s root directory, so Mac owners are going to have problems unless FiiO either sort this out, or warn of the issue on their website/instructions.



The K5 dock is a small desktop unit 120mm wide and 130mm deep, not including protruding plugs etc. The X7 simply plugs in on top, connecting through its small microUSB OTG connector. This is usually a 5pin serial digital link but as the rear digital inputs are simply pass-throughs to allow file loading from a computer, it seems that X7 connects to K5 through an analogue link within microUSB, not digitally. There is no DAC in the K5 it seems, hence no independent digital input as such: the digital inputs are pass throughs to the player. 


FiiO's K5 dock has a small, plastic flip-up door on top that covers the docking connector

when not in use. Front switches select input and gain.


This link feeds a Texas Instruments TPA 6120 A2 headphone drive chip and it gives quite different results to the X7’s AD8397, delivering a massive 7.7V output maximum to headphones through the large 1/4in stereo headphone socket on the front panel – more than enough to drive any headphones; the big knob at front is a volume control. 

At rear are two 3.5mm stereo jack sockets, carrying Left and Right balanced outputs intended for the balanced (XLR) inputs of stereo amplifiers. There are also analogue inputs and outputs. 

FiiO say K5 has an internal power supply but it does not, coming with an external switch-mode delivering 15V at 1.5A – and unidentified as ‘FiiO’ or ‘K5’ by a sticker, so its identity and purpose will be lost amongst all the other under a desk if it becomes disconnected. The dock charges the X7. 





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