FiiO BTR3K: Thumb-Sized Powerhouse


Today we’re checking out one of FiiO’s newest Bluetooth amp modules, the BTR3K.

Along with Type-C dongles and true wireless earphones, wireless amp modules are a segment that seem to have seen a huge surge in popularity the last couple years. Back in 2018 FiiO sent over their very wallet friendly module, the uBTR. I was pleasantly surprised with the quality of sound coming from that sleek, compact device, giving me high hopes that BTR3K would offer up a similar experience in a more technically capable and feature rich device, albeit at a higher but still very affordable price (69.99 USD at the time of writing).

After spending a month (to the day) with the BTR3K, I can say that it has not disappointed. Let’s find out why.

Package and Contents The BTR3K arrives in a very cleanly designed package wrapped in a white sleeve. On the front is an image of the device along with the usual branding and model information, along with a wireless Hi-Res Audio logo tucked in the top right hand corner. Beneath everything is a list of supported high quality codecs; aptX HD, LDAC, SBC, AAC. The back of the sleeve contains nothing of note.

Sliding the sheath off the inner plastic tray reveals a multi-tiered experience. The top tier has two layers, the first of which is the BTR3K tucked tightly into a dense foam insert. Clear plastic sheets protect the glass faces that make up the front and rear of the device. Lifting out the foam insert and BTR3K reveals a smaller cardboard box within which you find a manual, warranty card, and lanyard. The bottom tier of this unboxing experience is a larger cardboard box within which you find the rest of the accessories. In all you get:

  • BTR3K
  • USB-C cable
  • Lanyard
  • Protective plastic case w/ clip
  • Manual
  • Warranty card

While in the grand scheme of things this isn’t a heap load of extras, it’s more than I’ve received from any other Bluetooth module and that is always appreciated. The clip case is all-plastic so I don’t expect it to take more than a couple tumbles, but it should protect the BTR3K and is nicely constructed. I appreciate that FiiO included this in-box versus making it an added cost you have to dole out later should you want the added protection or shirt clip function. It also fits the BTR3K without obscuring any of the controls or making them more difficult to access.

Build and Ergonomics FiiO has taken a page from current smartphone design with the BTR3K, but compressed it down into a compact matchbox sized device. The front and back of the BTR3K are both glass with clean rounded edges. The main body of the device is aluminum, coated in a smooth matte black paint. At the top of the device is the Type-C port for charging, while the opposite end contains the two output options; 3.5mm and 2.5mm balanced. Down the right side from top to bottom is the power button, a pinhole for the microphone, a multifunction button, and a volume/track rocker switch. The construction quality is outstanding with this tiny device feeling solid and premium thanks to the dense, weighty materials used, and fine attention to detail when it comes to fit and finish.

While the buttons are small, they are also very distinct shapes and well-spaced. As a result I rarely found myself pressing something unintended. Most devices roll the power function into the single multifunction button. Separating the two feels quite unusual on a modern device, but I’m fully on board. While uncommon, there were times I held the button too long on other devices (ex. Earstudio ES100, ADV Accessport Air) and shut them down without meaning to. That feels very unlikely to happen with the BTR3K since that function is on a button that will be used rarely. The rest of the controls are intuitive and in line with how you interact with other similar devices. Tap the volume rocker to change volume, hold for two seconds to skip tracks. Tap the multifunction button to play/pause/answer and end calls. Hold it for two seconds to reject an incoming call. There isn’t anything unusual here and the learning curve is very quick.

On the front of the device shining through the glass pane is the FiiO logo that lights up various colours when the BTR3K is powered up, advising you which codec is being used.

  • Blue – SBC
  • AAC – Cyan
  • aptX, aptX LL – Purple
  • aptX HD – Yellow
  • LDAC – White

As someone whose eyes are unable to accurately determine some colours, this feature isn’t particularly useful. For nearly everyone else, it should be handy for quickly determining that you’re connected with your preferred codec.

Another nice feature is automatic device switching. Once you have connected to both device, if you want to switch from one to the other you simple pause playback on the current device and manually start playback on the second. If something is already playing on the second device, the switch will occur immediately. I tested this with my LG Q70 and ASUS FX53V laptop and it worked as expected, though the switch to the laptop could be a bit slow. I suspect that’s down to its older wireless hardware and clunky software.

Bluetooth The BTR3K uses Qualcomm’s CSR8675 Bluetooth chip. Some benefits of this are low-power consumption, a 120 MHz DSP, and support for 24-bit transmission and processing among various high quality wireless codecs like SBC, AAC, aptX/X LL/HD, and LDAC.

Connecting the BTR3K with your device is as easy as ever. Press and hold the power button until you hear a pleasing chime, the FiiO logo on the front starts flashing, and the device boots up. On your source, search for available Bluetooth devices and the BTR3K will show up very clearly as “FiiO BTR3K”. Once connected, you’re off to the races.

The wireless connection with this device is rock solid. I have yet to experience any stutters or drops in regular use, except when maxing out the range. The cheaper uBTR is slightly better in this regard in that I can go about an extra 10 feet before it drops, but otherwise the BTR3K is excellent and is competitive with everything else I own. I can place my source device in my office and walk anywhere in the apartment, except to the front door. It will happily retain a good connection across three rooms and down a hallway with numerous obstacles in the way. Even when outside in interference rich locations, like the rear entrance to our apartment oddly enough, it holds strong.

USB DAC The BTR3K can be used over Type-C usb as an external DAC (dual AK4376 chipset) for your computer (and probably your phone if you’ve got the right cable on hand and want to be weird like that). Once the BTR3K is plugged in, turn it on for it to register as an audio output device. Select it and away you go. There is very little fuss and as a nice bonus, you can charge while listening. Sweet.

Noise To test noise from the 3.5mm and 2.5mm balanced outputs I used the Dunu DK-3001 Pro (20ohms, 112dB +/-2). It is fairly average in terms of driving difficulty and sensitivity and has a modular cable system and as such can utilize both outputs. Through the 3.5mm output, noise is nearly inaudible with nothing playing and impossible to hear once you’ve got music playing. Switching over to the 2.5mm balanced out there is noticeably more noise, but it’s still easily masked with music and only audible during very quiet moments otherwise. Tossing on something much more source picky like the Campfire Audio Solaris (10ohms, 115dB) reveals more audible noise through both outputs (Brainwavz Candy Cane 2.5mm balanced cable used here), especially the 2.5mm. Still not terrible by any means but if you’re bothered by hiss, even an amount that is barely audible, try to avoid pairing VERY sensitive iems with the BTR3K.

Battery The BTR3 has pretty decent battery life and a pleasantly snappy charge time. At 1.5 hours, you can be up and ready to listen faster than most (2 hours seems to be the standard). The claimed endurance is 11 hours. While I did attempt to properly time and test this, I kept forgetting to check in and always missed the exact time of death. That said, it was somewhere between 10 and 11 hours since the BTR3K has always run dry by the time my 11 hour alarm went off. As long as you’re not using it for marathon listening sessions, you should get a few days of listening out of it before needing to top up the battery.

Sound Quality I’ve really been enjoying the BTR3K’s presentation which is very smooth, detailed, and slightly warm. It pretty much takes everything I loved about the uBTR’s sound, and makes it cleaner and more capable.

Treble is well extended and if there is any roll off, it’s occurring well beyond anything my ears are capable of hearing. As a result of this, testing with bright earphones like the TinHiFi T2 Pro or EarNiNE EN2J results in all the aggression and sharpness being retained. Nothing is being smoothed over and I don’t really hear much loss of detail when compared to the BTR3 in DAC mode, or with dedicated DAC dongles like the Cozoy Takt-C. While normally I’d follow this up with something like “given this upper energy retention, it might be best to avoid pairing bright earphones with the BTR3K”, that’s not the case here. The BTR3K actually works quite well with bright earphones since the qualities that go along with that style of tune are retained.

The midrange of the BTR3K has a neutral presence in the mix. Notes are well-weighted, fairly dense, and on earphones with a lean presentation, such as FiiO’s own FH1s, sound more filled out and complete. Midrange focused earphones like the ADV Model 3 BA2 and EarNiNE EN1J retain the qualities that make those frequencies so attractive. On the EN1J it’s the breathy, wispy timbre and on the BA2, the rich vocals that remain just as lush and intimate as they do through most of my wired DACs. Outstanding timbre quality, like that from the thinksound On2 or Shozy Form 1.4, is retained so you don’t have to worry about the BTR3K hindering your earphone’s accuracy.

Bass out of the BTR3K is awesome. Shozy’s Form 1.1 and 1.4 have some of the most addictive bass I’ve heard recently, and through the BTR3K retain all the head thumping glory that I fell in love with in the first place. All the texture and weight those earphones are capable of reproducing is present, as is the outstanding extension with deep notes providing the visceral rumble I expect. The slight amount of warmth the BTR3K injects into the presentation isn’t enough to be a hindrance, unless we’re talking something like the Massdrop x Mee Audio Planamic which ends up a little warmer and darker than I like, even if the wicked bass of that model is also going full force through the BTR3K.

When it comes to the sound stage the BTR3K continues with another strong showing. Pair it with something expansive sounding like the Campfire Audio Solaris and you’re in for a treat. Staging retains the depth and width such an earphone is known for with imaging quality that is only slightly hindered. I noticed no drop in quality in song layering and instrument separation, even at volumes I’m uncomfortable with. Everything remains well defined and coherent.

Overall I’m pretty floored by the sound quality the BTR3 outputs. It is clean and dynamic with great extension and high definition codecs that can take advantage of a high quality source and top tier headphone. While it’s not quite as powerful as the Earstudio ES100, it’s better built, more affordable, and if my memory serves me right (the ES100 died a while ago), sounds just as good but with a slightly more coloured sound.

Final Thoughts The BTR3K is the real deal. It’s great to look at, even nicer to hold and interact with, is priced VERY competitively, supports hi-res codecs, has standard and balanced outputs with dual AK4377 DACs, can be used as a USB DAC, and has impressive range and wireless stability. The packaging is of good quality and it contains some useful extras like a case/clip and lanyard.

Honestly, the only things I have found to complain about are the tiny bit of hiss present with sensitive earphones, and that the output power of both the standard and balanced outs are not particularly strong. It’s definitely enough for the vast majority of products though, and probably anything anyone in this price range is likely looking to carry with them out and about.

If you’re in the market for an affordable Bluetooth amp under 100 USD, the BTR3K is absolutely worth checking out to see if it meets your needs. As for me, this is taking up the mantle my ES100 (RIP) held and will be my acting daily driver DAC/amp. Let’s see how it holds up long term.

Thanks for reading!

– B9

Disclaimer A big thanks to Sunny with FiiO for sending over a sample of the BTR3K for the purposes of review. The thoughts within this review are my subjective opinions of the BTR3K and do not represent FiiO or any other entity. At the time of writing the BTR3K is selling for 69.99 USD. You can check it out here:



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