FiiO BTR3K-FiiO brand new balanced high-fidelity bluetooth amp

Dobrescu George

Reviewer: AudiophileHeaven
Receive Signal – Send to Chifi – FiiO BTR3K aptX Bluetooth DAC – AMPs
Pros: + Build Quality
+ Size
+ Warm Thick sound great for Bright Chifi IEMS
+ All the codecs supported
+ comes with a case
Cons: - Less Driving power than BTR5
- Less detail than BTR5
Receive Signal – Send to Chifi – FiiO BTR3K aptX Bluetooth DAC – AMPs

BTR3k is the more affordable Receiver mady by FiiO, priced at 60 USD, and it will be paired with Fischer AMPs FA-4E XB, IMR R2 Aten, and Dita Fidelity. For the comparisons, it will be compared extensively throughout this review with BTR5, and also with iBasso DC01, FiiO M6, and Cyrus Soundkey.


BTR 3K is more of a downsized version of BTR5 with a warmer, thicker, smoother sound, but also a more portable design, yet still as amazing as the more expensive brother, as we’ll explore in today’s review.

It should be noted that I have absolutely no affiliation with FiiO. I’d like to thank FiiO for providing the sample for this review. This review reflects my personal experience with FiiO BTR3K. Every opinion expressed is mine and I stand by it, the purpose of this review is to help those interested in FiiO BTR3K find their next music companion.

About me


First things first, let’s get the packaging out of the way:

Although you may think that you could have used a bit more extra in the package of BTR3K, like some cable adapters, since it also supports balanced connectors, or at least an OTG, those are easy to find, and including them would have increased the price of BTR3K which really wasn’t the point of it.

You get all the cables you may need, or better said a charging cable. The package may not feel like much, but the price of BTR3K is really good too, so I would rather take this package, since the most important accessory is included, which is that case.

What to look in when purchasing a high-quality entry-level Bluetooth DAC/AMP

Video Review


Build Quality/Aesthetics/Functionality

BTR3K is downsized in every way from BTR5. The weight is smaller, its shape is smaller, which means that it is much better for running and jogging, it is less powerful though, and it can mainly drive IEMs, where BTR5 can do headphones just fine, and even hard-to-drive headphones like HIFIMAN Deva, Sundara, Brainwavz Alara, Verum One and many others, making it more versatile. BTR3K is specialized on IEMs and Earphones, and it can also act as a bluetooth receiver, USB DAC, and has the same wide-codec support for bluetooth codecs like BTR5.

The one difference that you will notice is the lack of a display, as only BTR5 has one, while BTR3K has a glowing logo that you can rely on.

The bluetooth signal strength is similar, so you won’t have issues with either, and BTR3K also sounds better in wired mode, if you want to take it to the maximum. We’re still talking about a Type-C port, so FiiO did not cheap out when designing BTR3K.

Talking about the tech inside both would take quite a bit, they rely on different DAC modules, as well as AMP modules, and FiiO pretty much stretched the budget as much as they physically could to put everything that was humanly possible in both modules, making them the best versions they could.

Besides the huge differences in sound between the two, BTR3K is still always going to be a bit more portable, and I did my best to include photos of them next to each other to highlight just how much more portable it is. I would and did use both as affordable desktop DAC/Headphone Amplifiers, especially on-the-go and for laptops being top notch.

Sound Quality

The sound quality will be different between the wired and wireless mode, but depending on what music style you enjoy the most, the differences may be too small to notice, especially on-the-go. I tend to max out the volume while taking a walk, which is why I noticed the differences quite a bit. If you prefer to listen quieter, you may not notice the differences, and with commercial music, as well as classical, there are less differences between the wired and wireless mode than with metal, rock and complex EDM.

The sound of the BTR3K is very clearly warm and smooth, with a thicker presentation, less treble energy than BTR5, and it very clearly favors neutral and bright IEMs, rather than warm and natural ones. The trick with BTR3K is that it is affordable, mini-sized, and most probable to be paired with a Chifi IEM, all of which are known for their fairly strong treble and bright signatures.

The bass of BTR3K is fairly natural, and edges on being slow, it is large, creamy, and has a good weight. With IEMs, it reaches the bottom end nicely, and delivers both a good rumble and impact. On the other hand, it is not quick enough for death metal, and I would stick to EDM, Dubstep, Rock, and even slower metal, as well as Jazz or classical with BTR3.

The midrange of BTR3K is warm, a bit colored from the bass and lack of treble, as the upper midrange is less expressed than BTR5. This means that it is smoother, more musical, easier to enjoy, especially with bright chifi IEMs, and if you’re a leaner, and fuller signature lover, BTR3K will be right up your alley. A lot of soundstage width with BTR3K, and thanks to its fuller and deeper sound, it also gives the feeling of depth a bit more. The instrument separation was still a touch better on BTR5, but BTR3K is impressive in its own right.

The treble of BTR3K is smoother, less sparkly and less energetic than that of BTR5, but still fairly complete and energetic by itself. It has the best synergy with bright IEMs, and pairing BTR3K with dark IEMs is not recommended, because it may result in a fairly dull sound.


It was hard to find anything to compare the BTR3K to, mainly because it is at a price point where most other products do not focus so much on the sonic performance but on offering a functional package, but from the sea of competition, I went with FiiO’s own M6, Cyrus Soundkey, and iBasso DC01.

All of those are more or less in the same price range as BTR3K, although the Soundkey is a bit more expensive usually.

FiiO BTR3K vs Cyrus Soundkey (60 USD vs 150 USD) – The Soundkey is like a mystical object from a story, as it has a good mix of having an excellent sound, one that can compete with BTR5, but also has a fatal flaw, which is the microUSB port. That, and having no balanced connector, which is a pretty usual thing even in the entry-level price range, makes it hard to recommend the Soundkey more, except if you’re going for sonic quality alone, as the Soundkey has more dynamics, more detail, more clarity and punch than BTR3K.

FiiO BTR3K vs FiiO M6 (60 USD vs 150 USD) – M6 is a full fledged DAP, or portable music player also made by FiiO, but for a much higher price. The main reason I included it here is that I already stated that BTR5 outweighs it when it comes to sonic quality but between M6 and BTR3K, it is another story. M6 is more analytical, more detailed, but doesn’t really have more driving power, and struggles to make a compelling competitor for BTR3K, which ends up being more convenient to use often, especially as I’ve grown quite accustomed to having bluetooth, and although I dislike notifications interrupting my music, and M6 would make a great tiny DAP, the shape and size of BTR3K make it more likely to be grabbed when you’re going for a jog or for a run.

FiiO BTR3K vs iBasso DC01 (60 USD vs 50 USD) – DC01 is less expensive than BTR3K, and sounds similar, a bit warm, full, somewhat smooth in the treble, but the largest difference is that DC01 does not have bluetooth support, while BTR3K does. It may sound like it is easier to pick DC01, but there’s also the support issue, where FiiO products are mainly supported by local agents, while iBasso also offers direct warranty. Another big difference is how warm and thick both are, with DC01 being quite a bit warmer, smoother, fuller, but also a bit more dynamic and clear than BTR3K.


The pairing list will include a few extra special products, like IMR R2 Aten, Dita Fidelity, and Fischer AMPs FA-4E XB. All of those are much more expensive than the BTR3K from FiiO, but all of them make fair pairings as BTR3K works well with more neutral or brighter / more aggressive IEMs.

You may notice that I haven’t included many headphones in the pairing part of FiiO’s BTR3K Review, but that is because the driving power is not quite enough for most headphones to be turned loud and have good dynamics, I would suggest using BTR3K mainly for IEMs. It works fine enough for easier to drive headphones, especially dynamics like Meze 99 Classics, Ultrasone Signature DXP, ESS422H, and the OVC Tube-Powered Headphones.

FiiO BTR3K + Fischer AMPs FA-4E XB (60 USD + 450 USD) – The trick with the long-named FA-4EXB is that it is quite neutral, to the point where it doesn’t have much bass or much treble. BTR3K gives them a fuller sound, with a smooth edge, which makes this analytical monitor well-behaved, keeps the excellent detail retrieval abilities, but doesn’t compromise on the musicality, and even when it comes to the dynamics and the driving factor, everything is simply excellent. You could use BTR5 for FA4EXB if you wanted more treble sparkle, but the musicality of the pairing with BTR3K really caught me by surprise.

FiiO BTR3K + IMR R2 Aten (60 USD + 500 USD) – R2 Aten is one of those more aggressive IEMs, which is V-Shaped, or rather has a sound that can be described as varying degrees of V-Shaped, with some of the filters being quite neutral, while with others having a huge bass, but never having quite that relaxed of a treble, if you want to have detail. BTR3K is quite handy here, because it has both an outstanding amount of detail, clarity and punch, but also manages to take some of the edge off, leaving the punchy and hard-hitting nature of R2, but making them easier to listen to for long periods of time.

FiiO BTR3K + Dita Fidelity (60 USD + 1300 USD) – Dita Fidelity is what I would call a magic IEM, so refined, so clear and so detailed, that it forgot to center much on the musicality. BTR3K is quite great at taking some of the edge off, giving the Fidelity a fuller, more musical sound, and smoothing some of the treble, making them far less aggressive and more enjoyable.

Value and Conclusion

The value of BTR3K is simply great, it is not pricey for the quality and the options it has, including LDAC, aptX, aptX HD, aptX LL, and having both a balanced and a Single Ended Output, along with the small shape, all while still having a good battery life. In total, the value is simply excellent.

The package is a bit disappointing though, with not a lot of extras included in the package from the start, and besides the plastic case which you use to clip it to your shirt, you don’t really receive much extra. On the other hand, the build quality is great, a fully metallic device, with great support for bluetooth, which works as a USB DAC too, and which can drive pretty much any IEM on the market, and even most easy-to-drive headphones and portable headphones.

Not only that, but with its full, lush sound, smoother midrange and unintrusive, relaxing treble, BTR3K is a great pair for brighter, colder, neutral and typically aggressive or fatiguing IEMs and Headphones, making it an ideal source, especially if you’re deep invested in Chi-Fi in general.

At the end of this review, if you checked out FiiO BTR5, and if you didn’t feel like it was the right choice for you, or if you simply want a smooth, laid back DAC/AMP that supports all the bluetooth codecs out there, if you want it to be ultra-portable, and if you own brighter, colder or aggressive IEMs, I totally and fully recommend FiiO BTR3K for you.

Full Playlist used for this review
While we listened to considerably more songs than those named in this playlist, those are excellent for identifying certain aspects of the sound, like PRaT, Texturization, Detail, Resolution, Dynamics, Impact, and overall tonality. We recommend trying most of the songs from this playlist, especially if you’re searching for new most, most of them being rather catchy.

Youtube Playlist

Tidal Playlist

I hope my review is helpful to you!

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Headphoneus Supremus
A tiny device that beats much more expensive competition
Pros: TOTL build quality.
Provides the same sound quality wired and over Bluetooth.
Sound quality would be considered amazing at any price.
Extremely low price for a device with this sound quality.
Smartphone app allows to customize functionality and sound.
Cons: None whatsoever
Finally, a great Bluetooth companion for Takstar Pro 82 v2 - FIIO BTR3K!
Takstar Pro 82 thread

Left to right - Earstudio ES100, FIIO BTR3, FIIO BTR3K, FIIO BTR5, Qudelix 5K, xDuoo XQ-23, Shanling UP2, Shanling UP4.

Build quality is great, it doesn't get any better.
BTR3K comes with a removable plastic clip (like BTR5), unlike BTR3, which has a clip on its back permanently.
The "Volume up/down" button is much better than on BTR3, you can really feel it.
Volume resolution is 60 steps, so you can adjust it to your exact liking.
Using the FIIO Control app, you can use a 10-band equalizer (not over LDAC though), and choose different types of low-pass filters (mostly affects bass).

If you'll set BTR3K to "USB DAC first", BTR3K will still appear as the current audio deivce on your phone, but media playback on your phone will be muted.
However, if a call comes in - you will hear it through BTR3K.

I wish there was an option to turn off Bluetooth when using a wired connection, but there isn't one - so I have to disconnect BTR3K from the phone manually each time (to reduce noise interference in the wired mode).

Both have the same dimensions, but BTR3K is 2.5 grams lighter.
BTR3K looks very similar to BTR3, but it adds a balanced 2.5mm output at the bottom, and moves the USB port to the top.
BTR3K has slightly larger battery - 330mAh vs 300mAh, but both have the same battery life (up to 11 hours).
BTR3K is using Bluetooth 5.0 vs 4.2 in BTR3, but it is losing LHDC support because of this.
BTR3K is using a slightly more advanced DAC AK4377A vs AK4376A in BTR3, and has two of them.
Just like the much more expensive BTR5, BTR3K is using two independent crystal oscillators for 44.1kHz and 48kHz, reducing jitter.
Both drive 25mW into 32Ohm from the 3.5mm, but BTR3K can drive up to 78mW using the balanced 2.5mm output.

The only disadvantage in BTR3K is losing NFC, but I have never considered that feature important - you only use it once to connect to a transmitter (and not all of them support NFC anyway).

Sound impressions

BTR3K sounds exactly the same using Bluetooth (LDAC 660/990), as it does wired - so you will get consistent sound regardless of how you use it.
While BTR3K is limited to 16bit/44.1kHz and 16bit/48kHz in USB mode, I had no problem playing higher resolution files in Foobar2000, without any noticeable degradation in sound quality.

With Takstar Pro 82 v2, BTR3K was a revelation - I did not expect this level of performance from such a tiny and cheap device.
It's border-line synergy combo - but wrapped into a single device, which also provides Bluetooth!
Pro 82 v2 sounds very musical on BTR3K, regardless of connection type.
Throughout the entire frequency range, there is nothing to fault - even the bass is nearly perfect in both quantity and quality, only being very slightly improved by adding O2 amp.
BTR3K hits really hard with Pro 82 v2, and the bass has full body - really surprising for such a tiny device.

BTR3 sounded very transparent with Pro 82 v2, but the notes were too thin.
BTR5 had proper weight of the notes, but added a slight warm veil, losing the transparency.
BTR3K resolves both issues - the notes have the proper weight, while retaining perfect transparency, without even a hint of any veil.
BTR3K adds some very slight euphony to the sound, as if it has a hybrid tube pre-amp - I find this very pleasurable and accommodating in long listening sessions.
Thanks to this slightly euphonic sound, BTR3K is quite forgiving to badly recorded/mastered recordings, despite excellent detail retrieval.

Only comparing BTR3K directly vs SMSL Idea (Sabaj DA2) + O2 amp, I was able to rule it out as a synergy combo.
Standalone, it sounds better with Pro 82 v2 than any device in the picture above, except maybe Qudelix 5K - not because I think it sounds better, but only because I haven't tested it extensively yet.
Not only that, but BTR3K even sounds better standalone than SMSL Idea/Sabaj DA2, which sound a bit too dry without O2.
Unfortunately, BTR3K doesn't have the same synergy with O2 as Idea/DA2 - it sounds too perfect on its own to really benefit from an amp.

P.S. I do prefer ES100's sound for my IEMs, but I currently have 3rd one in 2 years dying on me - so can't really recommend it.


The microphone is very good, I constantly use BTR3K for phone calls/Zoom/Teams.


BTR3K sounds much better than much more expensive Bluetooth receivers such as FIIO BTR5 or Shanling UP4, at a much lower price.
This is really a no-brainer, a universal device that provides great SQ over any type of connection.
If you are looking for a single device to use in any situation - BTR3K is the answer.
If you listen to music mostly at home/office, you still would be better off investing in a synergy combo for Pro 82 - Comparison of DACs/Amps

Where to get
You can get it here:
Its normal price is 70$, but during the 11.11 sale (which is actually 2 days - November 11th and 12th), you can use Select Coupons to get 6$ off that, and then you can get "6$ off 50$" coupon playing Energy Lab in the Aliexpress app - bringing the total down to 58$!!!
Don't miss this opportunity!
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Thank you!
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Hello, is btr3k for the bang olufsen h6 suitable? Would it make significant difference in sound quality? By the way how about btr5, is there any difference about sound quality with it? Does btr5 provide better sound quality in addition to driving bigger headphones (high impedence ones)?
I like BTR3K sound much more than BTR5 - BTR5 is warmer sounding, and is less transparent.
BTR3K has a more natural, uncolored sound with natural brilliance.

B&O H6 would sound as good from BTR3K as it would sound over a proper desktop amp/DAC.


Headphoneus Supremus
Pros: Fantastic build quality and ergonomics – Features (ex. USB DAC mode) and codec support (ex. apxHD, LDAC) – Wireless range and stability
Cons: Slight hiss through either output with sensitive earphones – Power output not amazing

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.

IMGP2891 (2).jpgIMGP2894 (2).jpgIMGP2906.JPG

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

**If you enjoyed this review, there are tons more to be found over on The Contraptionist.**

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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Ever since starting reading amp reviews, a question has been on my mind: how can a device that introduces even a "slight hiss" be considered a valid addition to any setup that had no previous "hiss" whatsoever, especially when pairing that approval with "audiophile" terms like clarity, detail, and resolution? Serious question.
@lightweightbigsound Not really sure how to describe sound without using those "audiophile" terms, lol. Cutting cords automatically results in compromise and something like this seems more about boosting convenience while maintaining as high a quality sound as possible, within a limited budget. Plus you still need to consider when selecting an amp/dac/dap, wireless or otherwise that the products you're pairing it with are suitably matched. I deliberately chose a notoriously picky earphone (Solaris) to draw out and test for noise. Most people aren't going to pair a 70 dollar wireless dac with a 1200 dollar iem.
Continued: With something more reflective of the price point, like a Meze 11 Neo or KBEAR Diamond, there is no detectable hiss. I should have made that more clear and failed to do so. My apologies. The BTR3K is actually quite clean sounding with picky devices when compared to other dacs/daps/amps I've used, especially something like the Periodic Audio Ni which is way more expensive and quite limited in features. Another reason why stuff like the iFi iEMatch exists; cleans everything up for noisy sources or picky headphones.


Reviewer at hxosplus
Amazing value
Pros: - Great sound
- Fully balanced
- HD bluetooth codecs
- Tiny size
- Battery life
- Asking price
Cons: - Nothing for the price
We proudly present the world premier review of FiiO BTR3K.
Thank you FiiO for giving us the opportunity.
The sample was kindly provided by FiiO and it is still under their ownership.
This is my honest and subjective evaluation of the product.

You can get it from



It's been only a few months ago since FiiO launched their flagship mini bluetooth dac/amp the BTR5 with much critical acclaim and while we were thinking that we are done for a while FiiO surprised us by replacing the not so old BTR3 with a brand new version the BTR3K.
FiiO's R&D team taking into consideration the great demand for balanced dacs decided to revamp their mid tier mini bluetooth dac/amp and add a fully balanced output to it.
So the BTR3K was born and let's dive inside to spot the key differences from the older one.
The AK4376A dac has been replaced by the newer AK4377A in a two pieces fully balanced design.
Power output is thus raised to a whole 78mW under 32ohm load for the balanced out and although remains the same 25mW for the single ended one we now get greater current capability resulting to 50% more power under 16ohm loads.
Bluetooth receiver remains the CSR8675 but is upgraded to bluetooth 5.0 for even better battery consumption and operation range.
All the known codecs are supported up to the high definition ones aptXHD and LDAC.
One key difference is the use of two independent crystal oscillators found also in the flagship BTR5 for accurate sound reproduction with reduced jitter and greater stability.
External dimensions are the same miniscule 58x25x11mm but weight is reduced to 23.5grm even though the battery inside is raised from 300mAh to 330mAh!

Volume is independently adjusted in 60 steps using the side volume button were we also find the multifunction and power buttons plus the mic.
Build quality is improved with a full aluminium body covered in both sides with oleophobic 2.5D glass.
In the front panel the multi color RGB light with the FiiO logo informs us about the current codec in use and battery status while the type C USB connection is located at the bottom.
USB dac connection is also supported as NFC for fast pairing.
An extra protection transparent hanging clip is provided as a lanyard and a charging USB cable.
For full information and technical specifications please use the following link.


A great portion of the listening sessions were done with final audio's B3 and FiiO's own FH7 both single ended and balanced with the BTR3K paired with a smartphone and FiiO's M9 dap also under USB dac mode with a PC and several Android devices using an OTG type C cable.
We haven't experienced any problems with the Android OS and the BTR3K was instantly recognized natively without the need of a special app so we managed to listen to Spotify and Qobuz with great success.
With the very useful option to turn charging mode off the BTR3K runs on its own battery without draining power from the smartphone.
This feature plus a few others can be accessed through FiiO's music app available for Android and iOS.
Some of them include turning charging mode on/off , selecting the low pass filter , enabling various user configurable equaliser modes , altering idle time power off etc.
The best part is that all of this adjustments are stored into the BTR3K memory permanently and then can be used without the need of the FiiO app running.
Important update
While finishing this review FiiO released a brand new application specially designed to control all FiiO bluetooth products.
It is called FiiO Control and can be found here

FiiO claims a battery duration of about 11 hours and we are happy to report that under real life usage we managed to squeeze out about 9 hours of listening to high resolution material plus accepting calls.

Listening to music with BTR3K was a very enjoyable and musical experience without lacking severely in technical ability.
Overall tonality is flat and natural with a slight hint of warmth as we are accustomed to FiiO's house sound and AKM velvet dacs.
Extension is great to both ends of the spectrum without something annoyingly missing.
Lower regisrer is present reaching to sub bass if the program demands it , even and adequately controlled as not to sound one note never bleeding into mid-bass.
Mids are a touch prominent only to add a pinch of spice and high frequencies are fatigue free , crisp and easy going but without rolling off.
Detail is there and surprisingly good for such a device so with all our favorite tracks we were able to reach quite deep into the mix.
Dynamic behaviour left us satisfied especially with easy to drive iems as for the stage it felt wide enough although lacking in depth and height.
Staging , positioning and layering as detail retrieval benefit greatly from the balanced out.
Noise floor wasn't detected at least with the iems we had to our disposal so we are talking about a black background not to be expected from an entry level dac.

While listening to the BTR3K we were very tempted to try some from our full sized headphones to happily discover that the little "fellow" could run the Focal Clear pro and Sennheiser HD660S to loud enough levels and acceptable authority (balanced of course).
Performance may vary depending on the bluetooth codec being used and the best results as described above were attained with the wired USB dac connection.
Bluetooth connection negative impact is on high frequencies extension and timbre resulting to a thinner sound with some grain but nothing to really complain about as the overall performance remains the same.
All in all a great and satisfying musical experience for this mid tier mini bluetooth dac/amp from FiiO even without considering it's price.

Vs the BTR3

The BTR3K is a clear step up not only power wise but also in sheer technical ability and overall presentation as it objectively sounds better.
The only scenario to buy a BTR3 is for the very budget limited user without the need for a balanced out because you can now find them in heavily discounted prices.

Vs the BTR5

The BTR5 is the true flagship with triple the power output and it is technically more competent.
It extends better , exhibits more detail retrieval , is cleaner with better separation and more holographic stage.
Under USB dac mode BTR3K will decode only 48k/16bit while BTR5 will do up to 384k/32bit DSD256 plus the independent XMOS USB receiver.
Regarding musicality it is not necessarily better as it is more a kind of different presentation that being the ESS house sound vs the AKM one.
Of course it is also double the price and almost double the size so the buyer must judge carefully his needs and budget in order to choose.

At the end

The brand new mini bluetooth dac/amp BTR3K from FiiO is a clear winner.
It is a great step up from BTR3 with the same asking price and half of that from the flagship BTR5 while rivals do not offer balanced output at this price point.
With an excellent price to performance ratio and not very far behind in performance from the BTR5 it should be the easy choice for the majority of the users out there.
A very enjoyable musical experience with surprisingly good technical ability plus flawless and easy operation , tiny size and great battery life make this one our whole heart recommendation and deserving rightfully a full five star rating.

Test playlist -

Copyright - Laskis Petros 2020
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Hello sir! Will this work with the Dolby Atmos for Headphones app in Windows 10?
I am sorry but I haven't tested this app.
May you should ask FiiO support?
Ok sir! Thanks for the reply!
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