FiiO uBTR: Micro Machine


Today we’re checking out a budget friendly Bluetooth module from juggernauts in the portable audio industry, FiiO.

FiiO has been around since 2007 and quickly arose to become one of the premier Chinese manufacturers as a result of products like their iconic X-Series media players. Their current lineup is wide reaching and includes DAP, amps, earphones, accessories, and Bluetooth modules like the µBTR we’re looking at today. The µBTR is an entry level model, yet inside is the respected Qualcomm CSR8645 Bluetooth chip with Bluetooth 4.1 and aptX support. This chip is usually found is much more premium devices, yet here it is in a budget minded product like the µBTR (pronounced microBTR). For someone that wants to experience high quality audio, but doesn’t have the finances required for the premium products you would typically have to buy to experience it, products like the µBTR can be a lifesaver.

Let’s take a closer look at the µBTR to see how FiiO’s most inexpensive Bluetooth module performs over an extended period in the hands of an audio hobbiest like myself.


The µBTR was sent over by FiiO free of charge for the purposes of review. The thoughts within are my own based on two months of near daily use, and do not represent FiiO or any other entity. At the time of writing, the µBTR retailed for 34.99 CAD on Amazon, or 32.99 USD via FiiO’s official AliExpress store. You can check it out here:μbtr

Package Contents:

  • µBTR module
  • usb-C charge cable
  • Quick Start guide
  • Warranty card
  • Notice on using Bluetooth devices

While Bluetooth is infinitely more consistent and reliable now than it was, it is still a somewhat finicky technology. The inclusion of the notice regarding Bluetooth usage is welcome since it goes over what amounts to best practices regarding Bluetooth devices; how to retain a strong connection, how to address connection issues, etc. For Bluetooth users familiar with the technology, this information will be nothing new. But, for those for whom the µBTR will be their first Bluetooth enabled device it will be helpful in getting the most out of the product.


Weight About 13 g (incl. battery) Dimensions About 55*19*9.1mm (exclusive of back clip)
Audio Input Bluetooth connection (Bluetooth 4.1 supported) Bluetooth Codec Supporting SBC, aptX, AAC
NFC Supported MIC Function Supported
Headphone Output 3.5 mm stereo jack USB Port Type C USB
Volume Control Side buttons Charging Indication Yes (Red light flashes when powered off and goes off after charging completed)
Charging Time ≤1 h(DC 5V 500mA) Power Input Recommend DC5V, 500mA
Battery Capacity 120 mAh Drive Ability 16, 32 Ω (recommended)
Output Power ≥20mW (16 Ω/THD<1%)
≥ 10mW(32Ω/THD<1%)
Frequency Response 20~20kHz(aptX connection)
THD+N <0.05%(1 kHz, aptX connection) Output Impedance <0.3 Ω(32Ω loaded)
SNR ≥95dB (A-weighted) Crosstalk ≥ 78 dB(32Ω loaded)
Bluetooth Chip CSR8645

Build and Ergonomics:

The µBTR features an all-plastic construction. The majority of the shell is a smooth, glossy white plastic with the face covered in a clear strip of plastic to give the design some contrast. This design language is very similar to Sony’s MDR-EX15 earphones which use the same style. It looks better here than on the Sony where there are visible mounting points that give away the EX15’s budget nature. FiiO’s take on this design is coherent and attractive with excellent fit and finish. On one end of the µBTR is the 3.5mm headphone jack while the other holds the usb-C port for charging. Down one side is a small hole for the microphone, a single multipurpose button, and a rocker button that handles volume and track movement. The back of the unit is composed of a matte white plastic clip that stretches the length of the µBTR. The clamping force is reasonably strong and supported by a small protrusion that allows the µBTR to latch onto whatever you clip it on. It works quite well.

Ergonomically the µBTR is a success, though the controls might take a minute to get used to. The single multipurpose button is easy to find and differentiate from the rocker button below, and depresses with some physical feedback. It doesn’t depress with a really solid click though, but it’s satisfying enough and works as you would expect. Press and hold for a couple seconds and the µBTR turns on. If you have a pair of headphones plugged in, you’ll be greeted by a tune that reminds me of the introductory jingle for the local morning news crew. Once on it can be used to start and stop music, answer calls, and re-pair the device if it becomes disconnected. The rocker button depresses with the same feel as the single multi-purpose button and handles volume via single clicks. It will also skip back and forth through tracks, but note an oddity here. Holding volume down skips to the next track, while holding volume up skips back a track. This is completely opposite the norm. That said, I got used to it quickly and it feels natural in use. Weird, but it works.

Overall, the µBTR is nice to look at and well constructed with controls that at first seem a little odd but work quite well. If I were to levy any complaint it would be that the clear face plate scratches easily. Tempered glass would solve that problem, but that would likely raise the cost of the µBTR notably, and isn’t only aesthetic anyway. Scratches do not take away from the wireless or audio performance.


The µBTR features Qualcomm’s CSR8645 Bluetooth chip giving it support for Bluetooth 4.1 as well as AAC, SBC, and aptX codecs. The connection quality proved to be very strong and stable and is one of the few devices I can use anywhere in my ~1,100 sqft apartment, regardless of source location, without running into spotty or dropped connections. Range is rated at 10 meters, but it feels like more. Most devices I’ve got start to cut out when there is a wall or two separating them from the source, but with the µBTR I can walk from my office to the front door, a trip which spans three rooms and a hallway, and only experience drops once I step through into the hallway. It’s pretty impressive.

Outdoors where the µBTR would be more subject to interference, I didn’t notice any dips in connection quality. Leaving my building via the rear door really affects some of my wireless devices. I suspect this is due to the wireless camera systems they have set up. Despite this the µBTR retains a strong, unimpeded connection through the area. Using it in my local Tim Horton’s coffee shop which is usually packed to the brim with people and their cell phones, as well as university students on their laptops, the µBTR has no issues. It has proven to be a very reliable device regardless of the location used.

The only issues I’ve experienced with the connection quality so far were when paired with the Shanling M0. Sometimes the µBTR will simply stop outputting music. It remains connected but silent, even after power cycling. Only after the M0 is turned off and on again will the µBTR start playing music again. I also find that when paired to the M0 the multipurpose button works sporadically. Turning the M0 off and on usually fixes these issues with says to me it is the culprit, not the µBTR. Still, I felt it was worth mentioning anyway since the M0 works flawlessly with every other Bluetooth device it has been paired to. The same can be said about the µBTR since I’ve experienced zero issues pairing it to the F.Audio S1, Shanling M1, LG G5, LG G6, and my Asus FV53G laptop.


FiiO tested the µBTR’s battery life and found the following.

Battery Life About 9 h (tested with iPhone) Bluetooth Transmitter iPhone (AAC)
Connected Headphones M3 open earbuds (27 Ω) Volume The volume on iPhone is set to maximum;
the volume on uBTR is set to minimum firstly, then press volume “+” button 5 times.

To test this with my own equipment, I pulled out my FiiO EM3 (47Ω) earbuds, connected the µBTR to my LG G6 ThinQ (aptX), matched the volume settings noted above, and let it run from the start of my shift at 9:00 AM to the end of my shift at 5:30 PM. 8.5 hours later the µBTR was still going, but at the end of it’s rope according to the battery life indicator at the top of the screen on my G6. 8.5 hours of use can be met, while 9 hours certainly seems achievable if you’re listening at very low volumes or with a lower quality codec. Via aptX and given the high volumes many seem to listen at, I expect most should be getting just over 8 hours of play time with the µBTR.

Sound Quality:

FiiO’s products are generally known for providing a quality audio experience. If the µBTR is representative of this, then the rest of their lineup must be a joy to experience because it sounds outstanding, especially for the price.

Treble out of the µBTR is solidly extended with a smooth roll off. I find it retains the shimmer and sparkle of some of my preferred headphones and earphones with treble emphasis, like the EarNiNE EN2J and EchoBox Nomad, but smooths out the peaks and any rough edges to make them a bit more listenable over longer periods. This has a negative effect with dark or very warm earphones that are already quite reserved up top, like the Massdrop x Mee Audio Planamic and Brainwavz M100, in that what little treble energy they had is reduced even further. Overall I quite enjoy the µBTR’s treble presentation. It is clean and smooth with clear instrument separation and good detail.

The mid-range seems to have a fairly neutral presence with a note weight that is neither too thick nor overly lean. This makes the µBTR an ideal pairing with mid-range focused earphones like the EarNiNE EN1J and Fidue A85 Virgo since it doesn’t color or mask the qualities that make their mids so gorgeous. Vocal detail is reduced slightly when compared to running the same earphones wired to the source device, but it’s not noticeable unless rapidly flipping back and forth between the µBTR and the music source. This neutral, uncolored presence also serves to retain the outstanding timbre and realism of products like the thinksound On2 and Astrotec Delphinus5.

Bass is the one area of the µBTR that doesn’t impress quite like the rest of the signature. Don’t get me wrong, it still sounds wonderful but I find it lacks some punch and weight with a noticeable roll off heading into the sub-bass regions. This is audible when comparing it to the much pricier Radsone Earstudio ES100 and source devices like the ZiShan DSD and F.Audio S1. Even so, I don’t consider it much of a detriment given the µBTR is a 30 dollar device and it’s bass performance is still overall quite good. It pretty easily overshadows the performance of dedicated players like the Ruizu X02 and XDuoo Nano D3 which are lean and unrefined with a much more steep and prominent drop off in the bass. I would much rather listen to my music over Bluetooth through the µBTR than straight out of either of those devices.

The µBTR’s sound stage capacity is good. Airy, spacious earphones retain these qualities while congested earphones remain congested. It’s not going to make a stuffy headphone suddenly sound open and well separated. Imaging quality is something that tends to suffer through Bluetooth in my experience, but the µBTR performs well above average. The Brainwavz B400 is one of my imaging benchmarks and it certainly doesn’t sound handicapped when playing through the µBTR.

Overall, I find the µBTR to be an excellent performer. If I’m going to levy any complaints it goes to the background hiss that is present with more sensitive earphones and headphones. My Astrotec Delphinus5 still needs to be filtered through the iFi iEMatch to eliminate that quirk, while other products like the thinksound On2 display almost as black a background as they would when being run wired. Still at just over 30 USD I can’t really fault the µBTR for how it sounds. I get just as much enjoyment from my music through it as I do any wired device, and that’s really what matters most. The µBTR does nothing to take away from this.

Final Thoughts:

2018 has been a pretty wild ride. Chinese products have absolutely dominated the budget product sectors, and products like the µBTR are a clear example as to why. The price to performance ratio is through the roof. Fair enough; it’s not a feature rich module. There is no balanced out. It doesn’t work as a dedicated USB DAC. There is no LDAC support and no mobile app dedicated to it (though the FiiO Music app is pretty sweet and worth checking out anyway). Still, at the price you have to be realistic and expect that extras like those will be cut and saved for higher end modules in FiiO’s lineup.

With the µBTR, FiiO’s focus was placed on what matters most; sound quality, ease of use, battery life, and connection quality. All of these things were handled well and make the µBTR a great companion for your every day listening. It is well worth checking out if you’re in the market for an inexpensive Bluetooth module.

Thanks for reading!

– B9Scrambler

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