In this feature, we review the FiiO K7 BT which is a Bluetooth LDAC-equipped edition of the original desktop DAC and headphone amplifier. It is priced at $249.99.
Disclaimer: This was sent to us as a sample for our honest opinion. Headfonics is an independent website with no affiliate links or services. We thank FiiO for their support.
You can click here to learn more about the FiiO gear we have previously assessed on Headfonics.
Note, that this article follows our current scoring guidelines which you can read in more detail here.
Adding and removing features to a product, especially those that are not entirely necessary, is a reserved decision left for the manufacturers to make. We as consumers do not get to dictate what’s going to come out until we see the press release.
The announcement of the K7 BT however is a reminder that a voice when gathered in a crowd will make some noise. And the community this time has been heard by FiiO that they want a K7 with a tail.
Since most of you can recall that we did a full review of the K7 last year, it’s still as good a time as ever to revisit this popular product now that Bluetooth functionality has been tucked on the spec sheet. Watch out as well for our comparisons with other Bluetooth-capable devices and see how the K7 BT fares.
Tech Highlights
The K7 BT is simply answering a specific need, adding Bluetooth to the original K7 desktop DAC and headphone amplifier. FiiO accomplishes this through a Qualcomm QCC5124 for its Bluetooth 5.1 competence. Compatible with all modern formats, it can receive LDAC, aptX, and of course AAC as well.
Even though I was able to try FiiO’s app before with the BTR5 2021, it didn’t click immediately that this same in-house benefit is applied to the K7 BT as well. The K7 BT will pair with the company’s app where users can play with an equalizer, upgrade the Bluetooth firmware, and more.
One of the impressive things the K7 BT includes for the price is a fully balanced internal architecture. And it starts the ‘use two of this’ train with its DAC chips. Naturally, a dual AK4493SEQ is still inside the K7 BT like its non-BT counterpart.
The amplifier section includes two gain levels and a facility to switch on a hardware level between three different output modes. Of course, the analog design is twofold in number, with a separate THX AAA 788+ assigned per channel.
The power coming from the 4.4mm output is pretty decent at 2W for 32Ω headphones. The number slightly retreats to a still respectable 1.22W power delivery for single-ended usage using the same load.
Design
The blockish all-aluminum chassis of the K7 BT is softened by its rounded corners and smooth edges. While simple in impression, the precise details are what keep the K7 BT high on the list of well-made products.
On top of the K7 BT, there is a very shallow depression that is probably CNC-milled with the chassis just enough for the THX and Hi-Res Audio stickers. This is a minor but thoughtful detail that elevates and cleans the overall appearance of the unit.
I also like the soft inward recession of the face allowing the buttons, switches, and the volume wheel to be accessible without being too proud of the front of the device. The printed text is a bit small though.
There is no power button anywhere in the K7 BT because the function is integrated with the wheel located in the center. This is the first device I had that does this and I can tell that FiiO didn’t skimp. The fit is solid and the gliding action is very reassuring. It does however show a minor rubbery play when I’m fine-tuning the loudness.
I find it weird that there is no obvious K7 BT branding anywhere. The only place FiiO decided to badge its compact all-in-one is in a small fine print on the rear.
I/O
There is a compact 100-240V switching power brick included in the box of the K7 BT. And if for some reason you find it lacking, the unit’s DC input will require a 12V 2A replacement.
Copying every element of the K7, the BT version only added a Bluetooth receiver in its variety of inputs. It is still not very often that I find a DAC/amp combo that includes analog RCA in the list of choices which makes the K7 BT quite special for me.
Bragging a balanced internal design, the 4.4mm headphone output is the only interface on the K7 BT that fully utilizes the effort. It is to be acknowledged though that the left and right channels of the single-ended outputs are still pulling from the two distinct THX AAA 788+ amplifiers, only discarding the secondary waveform available.
Controls
I don’t know if it’s by design, but first plugging the K7 BT into the wall even with the power turned off, the input lights blink on my review unit. To bring it to life, the volume knob will produce a loud audible clatter while turning the wheel a step clockwise.
Not completely unlike starting an engine, the ring LED sweeps once with a rainbow of colors like the rev meter on a car’s dashboard. It will do this sweep again but now in a single solid color assigned for the sampling rate indicating the unit is ready and stable.
With the set of inputs aligned in a row, one of them will be always on. The plain black button on the left changes the input but I’m getting a slight delay in switching which makes repeated presses quite finicky and unreliable.
Making the K7 BT more flexible for a wider audience, controls for gain selection and output modes are built-in. The analog design and straightforward markings make it easy to understand for everyday use. Set for headphone use, I tested that both the balanced and single-ended ports can work at the same time.
FiiO Control App
If the K7 BT is not in Bluetooth mode, the app is useless since it only lists devices it detects nearby. Even though I had already paired the K7 BT to my phone, I had to repair it while inside the app before the status changed to connected.
Now that the app says the K7 BT is connected, the name can now be pressed to enter the control panel. And what the app does, it does well. Without going leaps and bounds to be different, it remains simple and useful.
I expect that wireless streamers are most likely to open the app for the status and equalizer page which can be both opened from the bottom of the screen.
Aside from showing the codec, and the device currently streaming to the K7 BT, it also lets users manage which codec they want to enable or disable. The equalizer is also full-featured and capable of deep management of frequencies from 32Hz to 16kHz.
The settings menu located in the top right corner offers a petite selection of customizability. Including over-the-air firmware upgrades will at least keep the unit fresh while supported.
Packaging & Accessories
The K7 BT box is one of the nicer ones out there. The reflective texts and graphics splashed around add to the anticipation of checking out the contents.
Unfolding the lid from the top, a divided bundle formed by two tightly fitted cardboard sitting next to each other is to be examined.
The bigger one has holes to pull from and houses the quick start guide booklet and the K7 BT itself. FiiO was nice enough to include covers for most of the ports and add a soft protective foam around the volume wheel.
The other plain black box includes the accessories. It has a familiar lineup looking at other products in the market. What’s important here is that the K7 BT now includes a Bluetooth receiver as indicated by the fairly nice antenna in the box.
If there’s anything I’d like to point out, it’s the length of the power cable provided. While the total distance covered extends when combined with the power brick, the 15-inch power cable won’t get you too far from the wall.
Sound Impressions
DAC/AMP
I first set up the K7 BT in wired mode to set a benchmark. To my ears, the combo is surprisingly safe sounding since I expected some level of oomph in the lows and the higher frequencies to not be as tapered.
Still, while the low-end is not the main star, its behaved elevation is what allows the midrange to shine. The subtler energy also protects neighboring objects since isolating kick drums as an example is attenuated by a pillowy diffusion of the reverb which can get blurry and lacking in bite at times.
With just the right amount of intimacy, the vocals on the K7 BT have a feeling of familiarity as they bring you into the moment. I still wouldn’t describe the airiness it returns as etched but I won’t let it discount the fact that the scale and weight of images here is what deserves the attention.
Stringed instruments maintain a metallic timbre for some honesty and end with a softness that moderates the sheen a little bit. This makes for a pleasing listen that is not too exciting on the ears but remains fetching.
I’m finding that brassier instruments have their characteristic immensity but the smoothness and lack of impact leave them less dynamic sounding. Electric guitars, on the other hand, are placed just far enough in space although height is similarly limited and dry sounding.
Bluetooth
I’m quite looking forward that activating the Bluetooth mode will not deviate too far from wired listening. The gist of it though is that the K7 BT is a slightly different animal when paired through the wireless receiver.
Basslines has lost some grandness to their arrival as it appears to be less diffused and open but the detail and bite mostly remained the same. And if the wired mode is already not accentuated, the Bluetooth tuning is even comparatively less impactful around the mid-bass.
The K7 BT also removed a bit of the flavor around the midrange. While losing some of the width is what allowed it to have a more etched presentation with breathier sections receiving the highlight it deserves, the tuning is now less alluring.
Violins are imaging well enough across the stage. The soft quality combined with the thinner timbre however places emotions to be more serious and detached.
A resounding audience applause has a raspy yet well-layered quality. The separation between images is not as refined as in wired listening but it doesn’t fall short of what a realistic space should be.
Click on page 2 below for pairings and our selected comparisons.
