⌈ The Chinese company HIBIKI was founded by an engineer named SoSolar. He has been designing devices for other companies in the OEM system since 2012, and in 2015 he introduced devices designed for his own company. In 2019, his first BDS (Binary Decoding System) converter was finally ready. We are testing his new SDS (String Decoding System) device. ⌋

HIS IS NO LONGER EVEN A "HARBINGER", but whole bunch of devices that come from China. For years, this market has been associated with cheap, poor-quality products, often counterfeit products of famous brands, but it also has a different face, a face of a modern country where people like us live, that is, enthusiasts. The Economist once wrote:

The popular belief that China is incapable of innovation needs to be revised. Chinese manufacturing companies, which account for a large proportion of innovation activity, have shifted significantly up the value-added chain recently. (...) Foreign companies that have come here to use the strength of human muscles want to use the local minds more and more.

⸜ source: JACEK POPRZECZKO, Smok rusza głową, „Polityka” no. 28, 7.07-13.07.2021 |PL|.

The author of an article regarding this phenomenon in "Polityka" adds that in recent years China has accelerated even more in the field of its own solutions and has become a leader in some areas. But not only large concerns benefit from it, because the basis of the Chinese economy are small and micro innovative companies. They benefit both from employees educated at great domestic universities, from employees of Western concerns, but also from Chinese educated in the West who returned to the country.

An example of one such manufacturer is HIBIKI, one of the newest companies, founded by a UK educated IT engineer, Mr. SoSolar. As you will read below, he has prepared a D/A converter from start to finish, together with PLL loops, clocks and D/A converters, by himself. So he did something that only the largest companies in the world are capable of.

⁘

| A few simple words…

⸜ A SHORT HISTORY OF THE COMPANY The founder of HIBIKI is Mr. SoSolar. He started in the audio industry in 2012, operating mainly in OEM area. In late 2013, the founder went to study in the UK and began to prepare his own projects. In 2015, Mr. SoSolar logged on hifidiy portal and began to record his product development process. His first product was an R2R decoder module, which was sold in small quantities. Unfortunately, his work was plagiarized and sold on Drop in 2018. Today you can find this solution in several Chinese products.

In 2019, he joined the special clock architecture to the module and upgraded the decoding architecture, and released the first finished machine he called the BDS (Binary decoding system). A new decoder based on the 5bit 1024x architecture was released in 2020, and it is called SDS (String Decoding System).

⸜ A SHORT HISTORY OF THE FOUNDER SoSolar itself is just an ID, but behind it is a cutting-edge designer born in the 1990s. In 2013, he began to work as an OEM manufacturer in the field of portable HiFi, and then went abroad to study AI technology. As it reads in company’s materials he believes that an AI can serve audio to a certain extent. SoSolar may conduct cross-border integration in the AI and audio fields in the future, so stay tuned.

He most often listens to classical music, pop and jazz. It doesn't mean that SDS can only play this kind of music. SoSolar also uses SDS to watch movies, TV dramas and other media.

The designer’s system features such components as Singxer SU1 / Weiss INT203 digital interface, Shanling T3.2 CD turntable, SDS decoder, Passlab INT150 integrated amplifier, and Wilson Audio Tunetot bookshelf speakers. He doesn’t particularly pursue high grade cables hence he mainly uses Grimm audio TPR and Audio Art I cables that in his opinion provide very accurate sound.

He also used: dCs Delius/Puccini, Meitner Ma1, MSB Platium3/Analog, Denafrips Terminator, MUSICIAN PEGASUS, Holo Spring, Antelopes Amari, Merging Anubis, Weiss Minerava/DAC202 D/A Converters, as well as Soulution 560 and BOULDER 866 amplifiers.

⸜ A SHORT HISTORY OF THE DECODER The SDS is a decoder with a 5bit 1024x modulator structure. In the HiFi field and even the Hi-end field, 512x upscaling is already a very high specification design. Yet the SDS allows direct upscaling to an incredible 1024x, which allows the modulation noise to be pushed higher.

At the same time, the SDS is equipped with cross era clock architecture and self-developed PLL with two different architectures. The first is the crystal-based voltage-controlled oscillator structure, which has been deeply optimized by the designer. After actual measurement, the actual performance of this crystal oscillator has surpassed the CVHD957. (We believe that there are no more than 5 manufacturers with the ability to develop crystal oscillators worldwide).

In addition, company has also developed an ultra-high-speed oscillation circuit based on inductance. The advantage of this circuit is that it is especially used for locking of external clocks and is widely used in the RF field. In the expression of sound, in terms of sound expression, the crystal based oscillator has a cleaner sound and the direct sound field is larger and more accurate, while the inductor based oscillator has a fuller and more effortless sound.

The decoding circuit part uses 72 analog switches for each channel and 144 analog switches for the whole system. In the analog part, they specially developed an ultra-high speed class AB amplifier circuit, which can perfectly carry the ultra large current. ♦

⁘

▌ DIGITAL TO ANALOG CONVERTER

THE BASIC ELEMENT DIFFERENTIATING THE TESTED Hibiki converter from others is a discrete D/A circuit. The vast majority of companies use ready-made chips from ESS, Crystal or - until recently - AKM (whose factory has completely burned down), because it is relatively simple, relatively cheap and gives surprisingly good results. However, if we want something different, if we want to have control over our product from start to finish, we have to make such a converter ourselves.

In this way, discrete circuits are created, i.e. composed of a series of resistors switched with transistors and controlled by programmable FPGAs. Each company writes its own control algorithms, so the sound of each of these systems is different. And this is how the Ring DAC by dCS, the Master Sound Discrette DAC by Esoteric, Organic by Linn, multi-bit MSB circuits, as well as circuits from the Chinese company Denafrips were developed. The founder of Hibiki prepared his own circuit, which is quite unusual - its architecture resembles a chain, which is why it was called SDS (String Decoding System), just like the converter itself.

I am talking about a 5-bit delta-sigma circuit that upsamples all signals, both PCM and DSD, by 1024x. By increasing the sampling rate, it is possible to move the quantization noise much higher up the band and then simply cut it out with an analog smooth-slope filter. Upsampling can be set using a button on the front panel. The signal will be sent to it via one of the five digital inputs: RCA, BNC and Toslink (all S/PDIF), AES/EBU, USB and HDMI. The latter accepts the I2S signal and is characteristic of many Chinese companies.

The converter is relatively small, smaller than classic products, but looks solid. It arrived to the HF after being reviewed by some other magazines, so it was already a bit "worn-off", but still looked very cool. The letter H illuminated on the front panel in the logo and the illuminated buttons attracted attention. They allow user to select an input, mute the output, change the absolute phase, enable the PLL loop and activate the external reference clock. Above the buttons, there are multicolored LEDs that act as the user interface, because we can read the encoded information on the signal sampling frequency.

The device is fully balanced and has a dual mono design. The power supply is handled by an ultra-low noise circuit that gives a signal-to-noise ratio of -150 dB (!), and the audio path is separated from external noise by a special ground isolator. The precision of the timing is ensured by three large oscillators, designed and made by Mr. SoSolar. The chassis is made of aluminum, very solid, and the passive components come from the best manufacturers from around the world.

▌ SOUND

⸤ HOW WE LISTENED The Hibiki SDS digital-to-analog converter was tested in the "High Fidelity" reference system and compared to the D/A section of the Ayon Audio CD-35 HF Edition player, which also worked as a CD transport, as well as the D/A section of the Mytek Brooklyn Bridge file player.

The DIGITAL signal from the Ayon Audio player was sent via the ACROLINK MEXCEL 7N-DA6100 RCA RCA (S/PDIF) digital interconnect, and the USB signal from the HP Pavilion dv7 computer, on which I launched the Tidal service, via the USB ACOUSTIC REVIVE USB-5.0PL cable. The ANALOG signal from the RCA outputs was sent to the Ayon Audio Spheris III preamplifier with the RCA CRYSTAL CABLE ABSOLUTE DREAM interconnects. The most important thing for me was its behavior with CDs.

The device stood on its own feet and was powered by the Harmonix X-DC350M2R Improved-Version cable.

Recordings used for the test | a selection

⸜ LAURENCE HOBGOOD, BRIAN TORFF, PAUL WERTICO, Union, Naim Label ‎naimcd015, CD (?).
⸜ LAURIE ANDERSON, Big Science, Nonesuch 79988-5, „Expanded and Remastered for the 25th Anniversary”, CD (1982/2007).
⸜ MICHAEL JACKSON, Thriller. 25th Anniversary Edition, Epic/Sony Music Japan EICP-963-4, CD+DVD (1982/2008).
⸜ MIKE OLDFIELD, Man On The Rocks, Virgin/Universal Music LCC UICY-15274, SHM-CD (2014).
⸜ NAT ‘KING’ COLE, The Nat King Cole Love Songs, Master Tape Audio Lab AAD-245A, „Almost Analogue Digital”, Master CD-R (2015);
⸜ SŁAWEK JASKUŁKE for RAFAŁ BUJNOWSKI, Music on Canvas, Sławek Jaskułke/Core Port PROZ-10063, CD (2020);
⸜ TANGERINE DREAM, Rubycon, Virgin Records/Universal Music LLC UICY-40131, Platinum SHM-CD, (1975/2015);

»«

HIBIKI DAC offers an exceptionally good sound. It is not as good as the DAC in the reference player, I did not expect it, and yet I listened to the following albums with it feeling, so to speak, satisfied. Because everything I required of it it delivered in spades - nice timbres, dynamics and expression, and - that’s also important - its own expression, due to which it is not an ordinary, "one-of-many" good devices, but a product with a character.

Listening to the puristic recording, the Union, released by Naim Label, recorded by Ken Christofferson and mastered by the founder of the brand, JULIAN VEREKER, I noticed the great effortlessness with which the converter played this music. The instruments were arranged by the sound engineer to balance their sound in relation to the stereo pair of microphones.

The Chinese DAC brought the whole thing closer and warmed it up. It was especially audible on the bass of Brian Torff, whose upper range had a slight "puff", which added size to it, but also brought it closer to the listening position (microphones). There was nothing problematic about it, that’s how Hibiki delivered it. I am sure it was a deliberate choice made by the designer, and while discrete D/A converters also tend to do so, here it was carried even further.

How beautiful, how big, how warm was the voice of NAT 'KING' COLE from the The Nat King Cole Love Songs recorded directly from the analog "master" tape! The whole thing was brought closer to me, I did not have such a good gradation of layers as with the Ayon player, and the depth of the stage was not so clear-cut. And yet the presentation was mesmerizing in its tangibility. Because the vocal literally "hung" about two meters in front of me. It was not particularly clear, it was a DAC that presented a larger whole, without information about details, and yet it was so nice, so convincing that I just perceived it as a different view of the same material, not a worse one.

Wondering how the Hibiki behaves in the time domain, I reached for the Thriller by MICHAEL JACKSON. It turned out that the tested DAC conducts the rhythm perfectly, does not muddle it and does not slow it down. What's more, the internal tightness of the sound is so good that in the Billie Jean it was possible to perfectly follow the drums on the one hand, with a strongly guided kick drum, enhanced by the sound of the snare drum, and on the other the characteristic bass, laying the foundation for the whole track.

Also here the feature I talked about, meaning bringing sound sources closer and increasing their volume kicked in. So the sound from Jackson's album was massive, strong and big. As it turns out, it is a result of a slightly emphasized upper bass, but also of the DAC’s character. Together, it resulted in a very compact sound. My point is, there is no room for gaps, breaks. On the one hand, it's great, because the sound from each album I played was palpable and dense, but on the other hand, you have to accept the unification of the presentation.

To be honest, this is a departure from neutrality - the Hibiki DAC is not a color-neutral device and it probably wasn't supposed to be that way. But it's also not something that I would treat as a problem. What's more, by withdrawing the upper midrange, emphasizing some of the bass and bringing the sound closer (by warming it up) we get a DAC that sounds like a tube device, yet offers an excellent rhythm and is extremely dynamic.

All the above-mentioned albums are either well-recorded or superbly produced. Wondering how the device handles highly compressed, not very resolving material I reached for the MIKE OLDFIELD’s Man On The Rocks, released by Virgin Records in 2014. I have this album in the SHM-CD version, so potentially better, yet it sounds numb and dull.

As it turned out, the tested DAC neither emphasized the treble nor the brightness, which happens very often with this type of recordings. It deepened the sound, boosted the kick drum and part of the bass guitar, withdrawing part of the upper midrange at the same time. It resulted in a presentation that did not offend my hearing anymore and thanks to which I listened to this album, for the first time in a long, long time, in its entirety. It was not particularly resolving, let alone selective. Hibiki - with such recordings - cannot do that. And yet there was something about it that made the music flow.

As I said at the beginning: Hibiki is a device with its own clear sound character. It does not pretend to be "neutral", on the contrary - it influences the presentation in a specific and clear way. It boosts the bass, smoothes the midrange and brings the foreground closer. So we get a presentation with it, to some extent, similar to harmonically saturated tubes. The rhythm is kept exceptionally well, and the treble is silky smooth, and at the same time - as for what I described - surprisingly "present".

▌ SUMMARY

WITH THIS CONVERTER, YOU WILL PLAY any album, both well-recorded and poorly-recorded. With the former, the converter will show a lot of momentum, large volume and quite good separation of the instruments. But most of all, it will saturate the presentation with colors, a dense "envelope". With the latter, it will not be too selective, but on the other hand it will smooth them out and warm them up, which will give us a nice, pleasant sound. It will not be particularly focused, especially in the bass range, but it’s always quid pro quo.

You can shape how Hibiki sounds by using the PLL button and choosing whether you want to use upsampling or not. Without signal upsampling, the sound is more even, but also devoid of something that makes Hibiki such an interesting product - it deprives it of its soul. However, if we use its full potential, Hibiki will repay us with a full, warm, saturated sound, which makes life more beautiful.

▌ DESIGN

HIBIKI DIGITAL-ANALOGUE CONVERTER looks classic for this class of devices. Its front baffle is not as wide as that of full-size devices, and its outline is almost a square. The housing is made of aluminum plates, and the feet are plastic - this is the only element of the design that should be improved by every potential owner.

⸤ INSIDE The inside of the device looks great and is nothing like inexpensive Chinese products from a few years ago. The basis of the design is a large PCB with a programmable signal processor, which stores and executes the upsampling algorithm - signals from all inputs go to it. So it is also a digital receiver. At the inputs you can see transformers matching the input impedance. The USB input features a separate.

Next to the upsampling circuit there are three quartz oscillators. They were designed and made in-house by Hibiki. They are enclosed in metal screens.

From the top, two auxiliary boards with two channels of the actual D/A converter are plugged into the main PCB. At its input there is another programmable circuit which controls the switching of a series of resistors. This system is an independent development of the company. We are talking about a 5-bit Delta-Sigma (ΔΣ) converter with a sampling frequency of 1024 times the sampling frequency of the input signal.

At the front there are two toroidal transformers from the German company Talema - so far it was a principle for Chinese products was to use native components. Apparently, however, it was decided that it needed to be changed, because in addition to transformers from a reputable company, the power supply also uses six very nice capacitors from the German Mundorf and a dozen other Japanese Elna from the prestigious Silmic II series, i.e. with silk fibers. Therefore, the auxiliary circuits are powered separately, and the actual converters are supplied separately.

The outputs and input sockets are very neat - they come from the Swiss company Neutrik and are gold-plated. Press materials say that the output of the circuit was built to work in class A without feedback. And you can actually see surface-mounted transistors working in a balanced circuit.

The Hibiki DAC is a very nicely built device with a unique circuit, a circuit invented and developed by the company in-house. The use of high-class components from well-known companies only confirms this good impression. And only details, such as inaccurately galvanized sheets with which the transformers are screwed on, could be better - but these are only details. Beside that - a great job. ■