For a large part of users, their relationship with digital music is based on connecting headphones to their mobile phone and opening Spotify or any other streaming platform to which they are subscribed. If this is your case and if you don’t aspire to much more, then maybe the review of FiiO’s new DAC / Amplifier, the K9 Pro, probably won’t interest you too much (or maybe it will… who knows?). However, other types of users have long been acquiring or downloading digital files of the highest quality (Bandcamp is for them a place they go to again and again), or they are subscribed to streaming platforms such as Qobuz, which offer 24-Bit files / 192kHz.
This type of user is the one who, of course, cares about having a decent sound system as well, in which the quality of the speakers or headphones they use plays a prominent role. However, there are not so many who worry about improving the reproduction process of these files, trusting “blindly” on the sound card of the computer or smartphone that they connect to their headphones or speakers. And yet it is in this process, how the digital audio signal is converted to analog and therefore we can hear it, that much of the magic occurs. That is why, more and more, for the playback of music files, having a DAC has become an increasingly popular option.
What is a DAC and why are you interested in it?
The DAC (Digital to Analog Converter) is as its name suggests, the converter that “translates” the zeros and ones of digital music, into analog sound, which is what humans can listen to. This means that all the devices that you have in your house and that are capable of emitting sound, have their own DAC: your computer, your smartphone, your CD player … etc.
What is happening? That generally and with very few exceptions, the quality of the sound card integrated in computers and mobile phones is of very poor quality, so that when playing a digital file, even if it is lossless, much of the information is lost.
By having a dedicated DAC, however, the device correctly interprets all the information contained in the file and reproduces it with total fidelity, which together with good speakers / headphones… a much improved sound experience is achieved. In many cases, the Connecting a DAC to your computer or smartphone is as big a change as having been used to watching VHS videotapes and suddenly starting to watch DVD movies.
That said, is a DAC an investment that makes sense for everyone? Let’s go back here to the beginning of the article. If music is something “accessory” for you or if you are not a big fan, probably not. Now, if you spend many hours a day listening to music and appreciate quality and nuance… if you are passionate about music, then it is an investment worth considering.
An all-terrain DAC with support for MQA
Once we have come this far and have convinced ourselves that the DAC is a worthwhile investment, let’s see what FiiO and its new K9 Pro offer us, a very complete high-end DAC that also includes amplifier functions.
Designed to be used on a desk, the K9 Pro opts for an elegant design on a sober construction in black anodized aluminum, and in which a large wheel with a central volume stands out above all the control elements. To its right, five LED indicators that inform us of the audio source that we are using (USB, optical, coaxial, RCA or Bluetooth); and under these four flat buttons (power on the equipment, source input, gain and the selector of the different modes -heads, amplifier and DAC-).
To the left of that big volume wheel, we find two balanced XLR 4.4mm headphone outputs and 6.35mm unbalanced jack. This is joined on this front, a balanced 4-pin XLR port. What do we find on the back of this device? Basically, the input ports corresponding to these selectors that we talked about before (USB, optical, coaxial, and RCA), to which is added an RCA output connector and a 4.4 mm Jack connector. In other words: connectivity options are not lacking and in our case, being able to benefit not only from its functionality as a DAC, but also as an amplifier, what this K9 Pro offers has been enough for us to connect our PC, a CD player, a record player and a pair of external speakers.
And of course this is important, but as you can imagine, almost all the magic of a DAC occurs inside it, so let’s see what we find in this case. First of all, the Chinese company has opted to incorporate the AK4499 DAC chip from AKM Technologies. In this sense, we are talking about a high-end 32-bit chip, which supports the decoding of high-resolution audio signals with PCM decoding up to 32-bit / 768 kHz and native DSD512.
To give you an idea, a CD is usually recorded at 16 bits, most compressed audio files are encoded at 8 bits, while those found on HD audio streaming platforms do so at 24 bits. On these same platforms, the digital music that we can download has a sampling frequency of 480 kHz. In other words, we are hardly going to find an audio file that cannot be decoded with the highest quality and natively, since these 32 bits are equivalent to what we will find in the recording master of most studios.
In addition to PCM decoding, the K9 Pro supports the new MQA (Master Quality Authenticated) decoding, a very interesting technology since it allows audio encoding that achieves small file sizes (up to one tenth of conventional Hi-Res) and can be reproduced reaching HD quality. It is not trivial, because to reproduce these types of files, we will precisely need an MQA-compatible equipment: although they are lossy files, the technology they incorporate share interpretation protocols that manage to restore the quality of the file that was initially encoded. In this sense, its approach is more akin to aptX technology for CD-quality Bluetooth sending than to the infamous MP3 file.
THX amplifiers for cleaner sound
In its work as an amplifier, the Fiio K9 Pro relies on THX AAA (Achromatic Audio Amplifier) modules, which guarantee the power we need, while also providing a clean sound.
In fact, this is the very goal of THX when designing this module: to provide an amplification system that increases the signal and volume with maximum transparency, that is, without added elements that “soften” the signal.
What we found, as the brand promises, is a good quality in sound amplification with very little distortion, without the need for intensive energy consumption, which favors its positioning in equipment contained in size, such as the new from FiiO. THX further notes that in its new model, it achieves a reduction of crossover and harmonic distortion by up to 40 dB, which minimizes listening fatigue.
A noteworthy part of this equipment is that the DAC / amplifier function will change depending on the speakers to which we have connected the K9 Pro. In this sense, if the speakers are pre-amplified, we will have to choose whether we want to work with the DAC of exclusively (so we will not be able to use the volume wheel) or we choose the PRE option (pre-amplifier). Working in this case with a pre-amplifier will be useful if we have several devices connected to our equipment, since the signal that will reach the amplifier of our speakers (or even another amplifier that we may have) will be cleaner.
That this is a complete device is demonstrated by the fact that we can also play music through Bluetooth. However, and despite the fact that it is compatible with codecs such as AptX Adaptive / AAC / SBC, Bluetooth gives what it does and in this case, we will achieve a maximum transmission speed of 96 Khz. Interesting as an “extra” but of course, no one would be willing to invest 800 dollars in a computer, if what you are most interested in is being able to play music through this standard. The fact that in our tests we have also experienced several micro-cuts here, it does not help to recommend it for this particular point either.
Conclusions
The Fiio K9 Pro is a team that plays in the upper-middle part of the market and it shows in all the details: starting with its construction, continuing with its connectivity options and ending with its commitment to cutting-edge technologies such as the AKM4499 chipDAC or the THX AAA amplification modules.
If we also take into account that in the upper part of the market, these devices can reach 2,000 dollars without too much effort, that Fiio offers a competitive quality for 800 dollars is certainly an element to value.
We cannot of course forget that it is still a device if not for audiophiles capable of spending thousands of dollars on their equipment, yes for very demanding music fans and that in this case, thanks to the portability of the Fiio K9 Pro, they want to enjoy the best audio quality, for example when they are teleworking.
