TUNAI SQUARE: A promising bluetooth receiver for the youngsters


SOUND: 7.5/10
DESIGN: 9/10
VALUE: 8/10


  • Nice punchy bass and entertaining sound
  • Good overall clarity
  • Powerfull for its size
  • Great design that promess durability


  • Unbalanced sound that sacrifice neutrality for entertainment
  • Dark mid range and lower bass roll off
  • Wireless distance is just average

Perhaps i’m not a big fan of Bluetooth earphones, for the very reason I did not find any that suit my minimal audiophile level in sound quality, but i’m sure a big fan of Bluetooth DAC-AMP receiver and this love story even begin with subpar chinese one that I don’t remember the name but was very similar to the Alpha&Delta Bluetooth adpater, wich I try too and find practical but high in THD as well as low in power output.

No the real passion begin with very capable BT receiver like the mythical RADSONE ES100, wich is still my favorite of the ones I try, including the nice Xduoo XP-2 (wich have the advantage in unbalanced power output and stand-alone portable amp, but not in sound quality).

Now, I think that the overwhelming popularity of RADSONE ES100 overshadow other potent BT receiver like the one I will review today call the TUNAI SQUARE.

TUNAI SQUARE is about same size than ES100, even smaller if you don’t take in account the rubber material that cover it and act as a wise cable holder. Battery life is a little longer even if ES100 state a too confident 14hours, I guess they play it at lower volume possible because I never got more than 6H with it. The SQUARE state 7hours and perhaps surpass this.

Anyway, what is the most interesting part of Square is the use of nice Cirrus Logic CS43L36 high perfomance DAC-AMP. I tend to prefer cirrus DAC clear and dynamic soundsignature over the AK one, but it always depend how its implemented and here Tunai try to take as much advantage they can from the all-in-one DAC. One thing certain, is that the sound of the Square is a big step up from my LG G6, when I plug my KZ ZS10PRO in G6, everything sound congested, without any deep and air in soundstage, affecting imaging as well as low, mid and highs dynamic, it was such a breath of fresh air once I pluged it into the Square! No BS night and day difference, but does it mean its perfect?

Let’s see in this review if the Tunai Square can be a good alternative for near half the price of Radsone ES100.

This BT receiver DAC-AMP can be found for 50$ on Amazon.com

INFO (No specs founded but read DAC specs, it should give you hint!) :

CUT THE CORD – Instantly transform any wired earphones into Bluetooth wireless earphones – includes built-in cord management system with a clean, minimal design

  • WORKS WITH ALL APPS – Compatible with all streaming services like Apple Music, Amazon, Spotify, YouTube, Google Play Music and all your favorite music apps
  • HIGH RESOLUTION AUDIO – Enjoy CD quality thanks to aptX from Qualcomm, Bluetooth 5.0 technology and high quality CIRRUS LOGIC DAC with 114dB DNR to eliminate background noise (High quality MP3 or AAC is used for devices without aptX)
  • aptX LOW LATENCY – Get perfect audio sync with no lag when watching video and play games on your aptX Low Latency equipped device such as the Tunai Wand
  • FEATURES GALORE – Built in microphone for calls, Siri, Google Assistant – Bluetooth controls for play, pause, volume, etc. – Long 7 hour battery life – Range up to 164’ outdoors / 32’ indoors – Also performs as USB DAC

Cirrus Logic CS43L36 SPECS :
Analog Output

  • Stereo headphone output with 114 dB dynamic range
  • 2 x 35 mW output power into 30 ohms
  • -98 dB THD+N into 30 ohms with 10 mW output power
  • Headphone insertion/removal detection with wake
  • Headphone load detection

System features

  • I²S or TDM audio interface
  • 8 to 192 kHz sample rate support
  • Bypassable sample rate converters
  • Fractional-N PLL
  • Integrated power management

Parametric Specifications
Channel(s) Out: 2

Resolution (bits): 32

Dynamic Range (dB): 114

THD+N (dB):-98

Sample Rate (kHz): 8-192

Analog Power Supply (V): 1.8

Digital Power Supply (V): 1.1-1.94

Logic Power Supply (V): 1.1-1.94 and 2.5-5.25 (Battery Supply)

Operational Power Consumption (mW)

Output Level (Vrms): 1


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UNBOXING presentation is well done and minimalist. It include just the basic need for a Bluetooth receiver wich is a USB to micro usb cable for both charging and USB dac.

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CONSTRUCTION is two rubber piece, one plastic device hided between this particular sandwich and a metal clip in the back of it. Its very light but even if the hided plastic receiver look rather cheap its well protect by the rubber plate wich have control butons directly molded in rubber material. Only complain I can found is the cheap all plastic 3.5 output that can look a little fragile especially if we take in account that when we twist cable around the Square body it can make extra pressure in it.


DESIGN is refreshing and well thinked, wich I respect in a not particularly audacious Bluetooth universe that choose to create a rectangular piece of whatever material and put a clip on it. The fact its made of rubber with embended butons in it make it less prompt to water damage, but as the cheap plastic can be wet from top or side the design feel unfinish here, wich is a shame cause in some way its genius idea. The fact that we can twist earphones cable around the Square make it very interesting for portability, you can let it bent under you chin and its so light it will just pull down gently the cable wich is practical for iem with ear hook, for standard cabled iem you can use the nice metal clip anyway.

As well, we got every butons we need : volume, tracks changing, play and pause. I don’t know why but lot of DAC-AMP or BT receiver do not have this basic option. In other hand, I consider the power on-off buton too easy to press, wich can be problematic to unwanted shut down of the device.


CONNECTIVITY even if stated high range isn’t that good at all as the signal can cut at less than 10 meters even without ostacle in middle.

Stability of signal encounter some noise cuting without reason, i don’t know if its due to my phone but it happen with my SurfacePRO laptop as well. Not often, but still, its annoying. Anyway, one very nice

Hooking is very easy too and get recognize fast by my phone, once you connect it one time it will automatically connect next timewich is always welcome.

USB DAC work flawlessly and its plug and play. The sound feel more balanced and less coloured than with apTx bluetooth, wich make me suggest the soundsignature I will describe is not the stock one of AK dac. I most admit I prefer the usb DAC sound, even if less on the fun side.

INTERFACE is quite nice, especially due to all the butons we have, but something to note is that due to rubber buton that are small and not very clicky, pressing them can be problematic time to time, as they are very near from eachother you can press another one by error or miss your shot. As well, power buton can be hit by error resulting in closing your device.

BATTERY LIFE is quite good and can go up to 10hours at moderate volume, for my use, I get 8H wich is very impressive either.

POWER OUTPUT impress sincerly me. Because I was unable to find proper specs from TUNAI product description I check the cirrus dac-amp specs and read it can give 70mW into 30ohm and have 114db of dynamic range, wich is quite impressive for this size. I don’t feel any of my iem was particularly under amped even the hard to drive Senfer DT6.



Most of time its difficult to explain the sound of DAC-AMP because its not particularly coloured or its neutral with just subtle change in tonality, timbre and attack. Well, the Square isn’t neutral at all and choose a clear, detailed V shaped type of sound, wich can wow me or annoy me depending on music I listen or iem pairing. For this review I choose to use the KZ ZS10P¨RO and SENFER DT6 because one is easy to drive and the other less so.

So the Square have a unique musicality to it, very energic and mid bass centric, this mid bass is very impressive, its not just a bumped bass in DB, its super well rounded, fast and tigh, whatever iem I use it inject extra punch bravado that is aprticularly suited for any instrument, electro, rock etc. The issue appear when you want more mid range presence because they feel recessed even if they are extremely clear, it had dryness to it, it lack thickness and weight like the mid bass, and then the treble is super extended, delicate and detailed and another time had extra sens of space.

Yes, we have now SOUNDSTAGE AND IMAGING modulation with the Square, due to the coloured sound it tend to add air and spaciality so the imaging sound wider and deeper, the illusion is perfect until vocal try to take their place.

BASS have some lower end gentle roll off that make the mid bass more weighty and thick, the timbre isnt particularly textured, and even slightly warm, wich will tend to tame brightness of some iem including the ZS10PRO. I know this type of bass will really impress some, especially with electronic, but the particular mix of warmness, thickness and dryness will displease some to,

MID RANGE are notably recessed, but have brighter timbre to compensate this by giving extra clarity, lower mid is more recessed than upper mids, but this region sound a little unbalanced and will affect naturalness of violin, piano and vocal, but you will forget about it if percussions is more important to you. As say, its stay very clear and well separated, not congested.

TREBLE have extra energy that push microdetails fowards, wich again give extra liveliness and vivid energy. Still, lower and mid treble lack resolution and precision, that result in a mix of dark and bright sound.


The KZ ZS10PRO is a great pairing with the Square, it sound less grainy in timbre, have extra transparence and the mid bass is sincerly mind blowing, but it was already kind a good…its just that now is more rounded up. Problem is that sub bass became too shy and seriously lack body and proper rumble. MIDS was quite fowards before but now are slightly recessed, but it stay clean and not extra bass warm tame them so it became like a well balanced V shaped iem instead of rougher W shape one.Treble is a little more unbalanced but at the same time less splashy.


The SENFER DT6 sound very different with the TUNAI, but depending of music you listen it can be a plus. Sub bass became more controled due to rolls off that tame rumble and give more precision to mid bass, mid range became a little less fowards but still keep good transparency and widness. Treble became more vivid in upper highs but even darker in lower treble. All in all, it loose in accuracy and imaging but gain in punchiness.


Priced at 100$, the RADSONE EARSTUDIO ES100 is probably the best ultra portable Bluetooth DAC-AMP on the market, its reputation is irreprochable and the praise about its sound and powerfull amping do not stop.
In term of construction, its all plastic and its more prompt to damage as the TUNAI because of butons space being expose, it happen to me that I drop some substance on it and have to clean it meticulously so the buton can be press again. Yes, the butonlack click, but the plastic body is quite sturdy. Still, the rubber design of TUNAI make it very hard to break or damage with water or other substance. Inanother end, 3.5 and 2.5 aux look more sturdy.

In term of features, ES100 have way more ofthemmaking it a more serious audiophile DAC-AMP, it have both unbalanced and balanced output as well as a very usefull app to control all parameters of inner dac wich is a dual AK4375A. You have an equalizer, sound filters, oversampling, dual amping and lot of other features while you have zero of themwith Tunai (but can use equilizer app).

Dual amping make the ES100 more powerfull than the TUNAI, it is especially evident with 2.5 balanced output wich can deliver two times mores power than TUNAI.

And now, for the SOUND, well, the ES100 still is unbeatable and way more reference sounding than more coloured TUNAI. Sound is richer, more dynamic, a little brighter with good attack-decay in whole frequency range. BASS is more balanced and dig deeper with good separation and attack, it have less mid bass emphasis but a more realist timbre and tonality. MID RANGE is notably more accurate and natural and make the TUNAI sound quite dark and recessed, as well, layering is more dense and imaging more accurate. TREBLE is more balanced, showing as much details in low-mid-high region and giving richer timbre too, here TUNAI sound way more artificial and sometime a little metallic.

All in all, the ES100 is from another league and will satisfy real audiophile while the TUNAI will perhaps impress more the younger audio enthusiast due to its more coloured and some time more entertaining and bassy sound.


TUNAI SQUARE have plenty of quality to share, and even more plenty of fun. Its construction design is well thinked and quite practical and promess good durability due to being 90% water resistant.

It’s sound while not being tuned for mature audiophile can deliver a very powerfull, energic, punchy and entertaining listen when paired with right earphones, as well, its clarity and low background noise make it stand appart from most sub-50$ Bluetooth receiver.

Sure it is far from being perfect, especially in mid range resolution, but this type of soundsignature will be a plus for some.

All in all, at 50$, I think its a good choice for the young generation that find boring too neutral sounding audio source.

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