HIFIMAN HM800 Review: The world’s smallest R2R headphone splitter


Today, I will share with you a new product, which is the newly launched decoding amp by HIFIMAN: HIFIMAN HM800. Although TWS earphones are very popular now, for audiophiles who pursue the ultimate sound, more will choose wired earphones. As a portable fever experience in the next era of the 21st century, a mobile phone as a digital turntable is the most convenient way to use it. Therefore, the topic of chat today must be related to decoding amp.


As early as a few years ago when the decoding amp first appeared, we were discussing such a question: Is it a “compromise” for audiophiles?

I don’t think I need to answer this question at all. Looking at the various player manufacturers now, almost all of them are reluctant to produce entry-level players, and there are even a few particularly excellent decoding amp products that can replace some players. HIFIMAN HM800 is a typical example, it is by no means a decoding amp in the pure sense. We can even think of it as a decoding amp cable, or a splitter device on the headphone. It is very rare for such a small device to be equipped with an independent Class A and B amp (traditional “decoding amps” mostly use low-end and cheap Class D decoding chips). Its output power is as high as 40mw*2, and the thrust is great.


When I saw how it was named, I suddenly thought of the HM801, which led the industry into the field of professional audio players. As the originator of professional audio players, it brought us too many surprises more than ten years ago. Now, the appearance of HM800 has led a new trend: it will definitely become a special “little pendant” for enthusiasts.


The packaging of HIFIMAN HM800 looks very atmospheric, and the design style is “man” as always. When you open the box, you can see a headphone storage box, and all the decoding amp and other items are inside. The first time I saw it, it really surprised me, the appearance is very tough, with a strong metallic glow. It is about the same size as a RMB coin and weighs only 9.65g.


The core of HM800 is equipped with a HYMALAYA DAC chip based on R2R architecture independently developed by HIFIMAN. I believe that many enthusiasts are already familiar with this chip, and it has been used in HIFIMAN HM1000 and HM901R. Its signal-to-noise ratio is as high as 112dB, and the total harmonic distortion (DAC module) is only 0.0025%.

This HYMALAYA DAC chip with R2R architecture has already ranked the first echelon formation in its hardware performance indicators, and its power consumption control has come out on top. The HYMALAYA chip won the technical gold award in Japan’s VGP in 2022, which is also the industry’s affirmation of HIFIMAN’s R&D strength.


The design of HIFIMAN HM800 is ingenious. The signal output part of its headphone cable is separated from left to right, which can improve the purity of the channel signal, which is the first time it has appeared on decoding amp products.


At first, I was depressed about why the headphone cable is only 42cm, while the USB cable does reach 1 meter. This is quite rare in decoding amps, as most manufacturers prefer to provide very short USB cables to bring the decoding amp closer to the phone.


But in fact, when the decoding amp is close to the mobile phone, it is easy to have some problems. For example, when mobile phones are placed in crowded bags or pockets, they will “fight” with each other, and even cause injuries by bumping into each other. Now HIFIMAN HM800 is far away from the mobile phone and fully exposed to the outside, so you can think of it as a headphone splitter, with a weight of only 9.65g, it will not be cumbersome to hang on your chest. No one but an audiophile would like to have a small box hanging next to a phone that keeps colliding with it. Although it does not seem to have any technological content, a small change has greatly improved the carrying and wearing experience. What do you think of this wearing design?


HIFIMAN HM800 is not just a decoding amp. The original intention of its design is to integrate it into the “blood” of earbuds, making it a part of earbuds. Hang it on your chest as a neat splitter, and you’ll forget about the decoding amp when we’re using it. Do you like this design?


Now that we’ve just talked about its headphone cables, let’s take a look at these cables. HIFIMAN HM800 provides 3 types of headphone cables with plugs, namely 0.78/0.75/MMCX, which can basically be adapted to most of the headphones with replaceable cables on the market.


The workmanship of the wire is good, very soft, and the plug part has the specification mark and the L/R mark. The plugs connected to the decoding amp are all mmcx plugs of the same specification. But it should be noted that the 0.78 pin it provides is not perfectly compatible with all 0.78 headphones. For example, it is compatible with HIFIMAN RE2000 Gold/Silver/PRO, but not with Leisurely Audio E16, which should have a lot to do with the size of the pin protection shell on the cable. However, this kind of wire is not special, and we look forward to HIFIMAN launching more specifications of the plug wire in the future.

In terms of subjective listening, the earphone I use is LZ A4 PRO, which is a HIFI earphone with 1 dynamic+3 armature driver, and the plug is 0.78 specification, so we can use the 0.78 wire of HIFIMAN HM800 for connection. One end of the decoding amp is MMCX, the other end is the USB-C interface, and the headphone cable can be connected to the mobile phone.

I feel that the sound is very soft overall, a little warmer, but not stiff. Thanks to the independent class A and B power amplifier of the decoding amp, both loudness and energy are quite abundant. Listening to Zhao Peng’s “叶塞尼亚”, the combination is full of three-dimensionality, and every detail in the background music is very clear. When Zhao Peng’s voice appeared, it was not as thick as I imagined, but on the basis of maintaining a certain thickness, it highlighted the soft emotion and details of the vocals. In the overall music, the softness and analysis of the lines are more prominent, and at the same time, the “weight” of the music can be presented. Another point to make is that the HM800’s noise floor control is very good, at least I can’t feel the current sound. You can’t feel any discomfort in the sense of hearing, and it can even be comparable to some professional music players in terms of tone. This combination is very suitable for performing vocal pop (especially with the blue cavity tuning hole + red filter) and some pure music.


Now replace the JASPER with a MMCX socket, which is a single dynamic flagship earbuds from AUNE. This time I changed the platform: I used the exclusive mode of UAPP, which can stimulate the strongest strength of the front end. As a dynamic earphone itself, the sound with HIFIMAN HM800 is more stretched and loose, and it is also excellent in high frequency extension and sound field scale. I used the player to find a concert version of Lisa Ono’s “REVER”. The ensemble of cello and piano at the beginning of the song immediately grabbed my heart. I didn’t expect JASPER to be able to interpret the heaviness of this type of instrument. Each note seems to be beating in the heart, and each instrument performs its own function and performs smoothly according to its own rhythm. After 18 seconds, the human voice enters the ear, Lisa Ono’s voice is really distinctive, with a certain amount of thickness, and the typical jazz style comes on the face at once. In addition, this music has very bright flute and low frequency melody simulated by electronic instruments. I was pleasantly surprised that the high frequencies of this combination are very smooth, while the low frequency part can feel the clear reverberation.

Then switch to Sarah Brightman’s opera “Music Of The Night”. All the notes seem to pour into my ears from all directions, the space support is very good, and it stretches naturally and creates a big scene for you. In this music, the distance between the vocals is obviously farther than in pop music, but the singer’s voice is still very soft, as if it is slowly flowing into my ears. There is no particularly exciting element in the whole music, but it does not mean that it is very ordinary. The dynamics are more obvious, the loudness fluctuations can follow the highs and lows of the music and move forward bravely, and you will be given what you need, and you will not feel that there is something missing.

Regarding this earphone, many friends feel that the intermediate frequency is farther away. But with HIFIMAN HM800, this is rarely the case, especially when listening to popular vocals, the distance from the ear is relatively close. But I think this combination is best used to listen to classical music, the space extension is great, and it is very natural, and it has a unique place for the performance of the space scale. The overall sense of hearing is very balanced, and there will be no particularly abrupt places. But after all, it runs in exclusive mode, and the line sense is more prominent, between sharp and soft. I think this combination plays a role in taking into account the popularity of vocals, but it is more suitable for playing back music works of various sizes.


Of course, these perceptions are subjective. But in any case, judging from the combination of various headphones under the HM800, its sound is very complete. The built-in HYMALAYA DAC chip has an independent Class A and B amp, which has a large thrust and a power consumption of only 20mw. There was no problem putting the sound quality of the HIFIMAN HM800 into the first echelon formation of the decoding amp.

HIFIMAN HM800 is currently the smallest discrete R2R architecture audio device, small enough to use it as a headphone splitter. Whether you are a senior audiophile or an amateur music lover, this good-looking, easy-to-use and good-sounding decoding amp will definitely bring you great surprises.

Check lowest price of HIFIMAN HM800:



Please enter your comment!
Please enter your name here