The HiBy R6 Pro II was loaned for the purpose of this review and now is returned back to the manufacturer. I didn’t receive monetary or any other kind of compensation and I don’t use affiliate links. The price of the HiBy R6 Pro II is $749 and you can order it from the HiBy official store.
HiBy Music
Established in 2011, HiBy Music (or plain HiBy) specializes in research, development, and sales of high quality portable audio products. With over 40 professional audio R&D staff and nearly 10 years of experience in the portable audio field, Hiby has developed dozens of portable digital audio players (DAPs), earphones, USB DACs, etc. HiBy Music possesses its own IP over the whole audio reproduction chain, including key audio processing algorithms and ability to design its own FPGA-based audio processing chips.
HiBy is also well known for the HiBy Music application which is a free high-quality music player specially designed for HiFi and for developing their own OS, the HiBy OS which is based on Android and can be found in many DAPs even by third party manufacturers.
HiBy R6 Pro II
The HiBy R6 Pro II is the second generation of the R6 Pro which was one of the most successful DAPs by the brand. The HiBy R6 Pro II is an Android 12 based digital audio player which utilizes dual, flagship grade, AK4499EX and one AK4191EQ DAC chips by AKM in current output mode with complete separation of digital conversion and analog rendering.
HiBy is using an all-in audio architecture which equips the 8 DAC output rails of the AK4499EX each with their own I/V conversion, fully unleashing their potential; The dual AK4499EX are each set to dual mono output, and all rails of both DACs contribute fully to both balanced and single-ended operation.
The HiBy R6 Pro II uses a 4-section independent power supply design that is based on numerous sets of high flux, ultra-low internal resistance, fully shielded high power inductors. Power supplies are made independently for digital, decoding, preamp and output stages, for pure, uninterrupted power without interference.
One unique feature of the HiBy R6 Pro II is the Class A/AB dual amplification circuits that are freely switchable on the fly via the drop down menu. The Class A amplifier is driven by 2 OPA1652 and 8 NXP bi-polar transistors for zero crossover distortion and fast transient response. You can turn on Class A amplification to unlock stronger drive control at the same time as enhancing power and density of the sound, handling full-size headphones and complex loads such as multi-hybrid IEMs with aplomb. On the other hand, Class AB amplification mode yields longer play time, lower heat emissions, and is perfectly sufficient for most IEMs on the market.
HiBy R6 Pro II supports class leading DSD1024, 1536KHz/32bit PCM and MQA16X making it the player with the strongest decoding capability in the market. Android system SRC is of course bypassed for a bit-perfect playback. The R6 Pro II also supports two way Bluetooth wireless connectivity with all the high resolution codecs including UAT, LDAC and aptX HD. Additionally the USB type-C port can be used either as a USB DAC input or output to an external DAC and it can also act as a coaxial output with the use of a special USB to coaxial adapter which is not included and is pretty expensive.
Full technical documentation is available here .
User experience
The HiBy R6 Pro II is powered by the Qualcomm Snapdragon 665 SoC and 4GB of RAM to run the Android 12 OS. The embedded ROM is 64GB that is expandable with a micro SD card. You can download all your favorite applications or switch to the HiBy OS for music playback. The player is very fast and responsive, it can be used for multitasking, like browsing while listening to music, and effortlessly runs all streaming applications or third party music players. The DAP has a large and borderless 5.9″ IPS screen with 1080*2160 of resolution that is responsive and has excellent visibility but the colors are not that vibrant.
The chassis of the HiBy R6 Pro II is quite large, larger than the FiiO M11 Plus ESS but it can be operated with one hand at least for the basic music playback functions. Despite the larger size, the HiBy R6 Pro II weighs about 245g so it is lightweight and 50g lighter than the FiiO M11 Plus ESS.
You can access basic audio functions, like gain setting and amplification class switching from the drop down menu. For more in-depth configuration you have to reach for the internal menus. Except for the usual functions, like low pass filter settings, the player supports various audio plug-ins and has embedded a powerful DSP, called MSEB, a software developed by HiBy that allows deep sound customization with multiple options.
Controls and I/O
The HiBy R6 Pro II has a clean and simple design, all inputs and outputs are located at the bottom of the chassis. Except for the USB plug, there are also included balanced and unbalanced headphone outputs and separate balanced and unbalanced line outputs. The line’s output signal is variable and cannot be fixed so for the full scale output you have to set the volume to its maximum value.
The right side of the device houses the power button, the volume buttons and a working status LED while at the left side you will find the three playback controls and the micro SD card slot. The buttons don’t feel very firm and have a certain wobble around them, nothing though that affects performance.
Battery duration
The HiBy R6 Pro II uses a large capacity 5000mAh Battery which supports fast charging. The battery duration depends on various parameters like amplifier Class, the use or not of the balanced output, gain setting, streaming or playing local files etc. I got a playing time which varied from 5 to 7 hours at the best from the balanced output.
Design and build quality
The HiBy R6 Pro II features an asymmetrical design at the back panel of the chassis which combines a curved surface with aluminum waves with a triangle-shaped HiBy logo that leads to a glass protected top part with carbon fiber looks. The chassis is quite grippy but it has sharp corners and too many lines that can attract dirt between them. I am not that fond of both the aesthetics and the ergonomy of the player and I preferred using it with the included leather case. Of course, this is something purely subjective and your mileage may vary. Build quality is excellent without any cosmetics flaws or visible gaps around the screen.
Accessories
The package of the HiBy R6 Pro II includes a USB type-C cable, a USB C to A adapter, front and back screen covers, user guide and a real leather carrying case.
Power output and noise
The power output of the HiBy R6 Pro II is pretty low for what we are accustomed to from a mid-range DAP. The amplifier is able to provide a 2V swing from the single ended output and 3.5V from the balanced. These numbers translate to 125mW/32Ω or 383mW/32Ω respectively, lower than some class-leading USB DAC dongles. Most usual headphones, like the iBasso SR3 or the Focal Clear Mg can get pretty loud but the overall sensation is that they sound dynamically restrained and a little anemic while the DAP doesn’t feel at home with more difficult loads like the HIFIMAN Sundara. On the other hand you can always use something more efficient, like the Sivga Luan or the HIFIMAN Ananda Stealth, while both headphone outputs are dead silent without internal noise thus making the R6 Pro II an excellent choice for very sensitive earphones. A great matching was with the HiBy Crystal 6 II earphone which is pretty efficient and has a transparent, crystal clear nature with plenty of musicality which synergizes well with the sound signature of the player. The player gets quite warm after a while especially in the Class A amplifier mode.
Listening impressions
The overall impression while listening to the HiBy R6 Pro II is that it is a tonally balanced, musical and engaging sounding DAP with a harmonious nature and very natural timbre. Technical performance is also excellent when it comes to fidelity, refinement and resolution but the R6 Pro II is not the most dynamic or impactful sounding DAP, at least when more demanding loads are used. With easier to drive IEMs, the bass is full, dynamic, powerful and weighty but with a slightly soft attack and not as punchy. Leaving dynamics aside, the bass is fast, tight and controlled with class leading layering and definition while it sounds fine and resolving.
The mid-range is pure and crystal clear, very addicting and engaging thanks for its organic texture and the wealth of the colorful harmonies. The timbre is natural and the player sounds weighty and just slightly warm, absent from any artificiality. The HiBy R6 Pro II is one of the most capable DAPs of the category when it comes to instrumental and vocal realism, especially in Class A, a pretty impressive performance that is going to satisfy all hobby aficionados that seek accurate tonality and lifelike reproduction of their music.
The treble continues on the same vein as it exhibits a natural and smooth nature with a realistic timbre that is devoid of digital artifacts and metallic edginess. It is not lacking in extension and energy, it is luminous and airy with great clarity but it is so well tuned that it never sounds sharp or bright. Detail retrieval is great not only for its quantity but also in the way that all the finest particles are gathered and bonded together to add to the whole picture without giving the impression of an analytical and clinical sounding player. What is also great is that there is no loss of note weight as we rise to higher frequencies and that the player somehow manages to retain excellent speed but without getting too rushed.
The rendering of the soundstage is excellent for the category because it is open and spacious with plenty of depth keyring while the silent background helps a lot with the imaging as you can literally sense all the performers emerging and rising from total blackness to occupy their well defined positions.
The HiBy R6 Pro II is music and earphone agonist as it pairs well with everything, at least if you don’t have any extreme listening habits and value timbre more than plain technicalities. Needless to say that it is one of the best players for listening to classical music.
Class A vs AB
These two modes offer some audible differences that become easier distinguishable after a while and when you get accustomed with the R6 Pro II general sound profile. The Class A slightly enhances the driving capabilities of the R6 Pro II and offers better grip, stronger impact and more contrasted dynamics but adds just a bit of noise with very sensitive IEMs. The timbre also becomes a bit warmer and realistic while the soundstage gains a little in holography. The Class AB on the other hand is a touch cleaner and more transparent with better inner definition but also slightly leaner and more aggressive. Class AB is ideal for everyone who likes a slightly sharper and more energetic treble and wants to spice up the overall sound signature or needs the most silent background.
Compared to the FiiO M11 Plus ESS ($699)
The FiiO M11 Plus ESS is the mid tier DAP of the brand and it uses dual ES9068AS DAC chips to do the decoding and dual THX AAA-78 amplifiers that can provide 660mW/32Ω from the balanced output which is almost double than that of the R6 Pro II. The M11 Plus ESS is more compact than the R6 Pro II but surprisingly 40g heavier while it has a smaller, 5.5″ screen. It is equipped with a 6000mAh battery that can keep it running for more than 11 hours from the balanced output. Both DAPs are equally fast and responsive while the R6 Pro II has the advantage of the two, true, line outputs.
The M11 Plus ESS is more impactful and dynamic with better driving control and raw power delivery, than the R6 Pro II, with a slightly stronger technical performance in the low end but on the other hand, the latter sounds fuller and more organic. The same applies to the rest of the frequencies where the M11 Plus ESS continues to have the edge in technicalities but the R6 Pro II offers a sound that is more realistic and analog with less artificiality in the treble. The M11 Plus ESS is faster and more energetic with a wider soundstage while the R6 Pro II is smoother, warmer and more holographic. These players belong to two different sounding schools, the FiiO M11 Plus ESS represents the modern approach that aims for stronger technicalities while the R6 Pro II belongs to the”old school” that values timbre realism.
In the end
The HiBy R6 Pro II is a really excellent sounding DAP and maybe the best of the category when it comes to timbre realism and musicality. If you don’t plan to drive too difficult loads and you are looking for a DAP that will make your music sound alive and lifelike, then look no further, the HiBy R6 Pro II is the one to get.
Copyright – Petros Laskis 2023.
+ Tonally balanced and musical + Excellent clarity and transparency + Refined and resolving + Natural timbre without artificiality + Class A and AB headphone amplifier + Dead silent without background noise + Powerful DSP and various tuning plug-ins + Separate line outputs + Industry leading decoding capabilities + Lightweight despite the large size + Fast and responsive UI + Large screen with excellent visibility + Modern design + Excellent build quality - Restrained dynamics - Medium power output - Average battery duration - Gets pretty warm - Relatively large size - Polarizing design - Digital coaxial output needs special adaptor
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