Digital & Analog Calyx DAC 24/192 digital processor


The widespread trend at storing music in a personal computer and the always more refined technology that allows the use of PC as a source to the audio chain, have been starting a flourishing production of converters. These electronic devices, notwithstanding the few possibilities of competing with an analogue signal, can offer a concrete contribute to the progress of the digital tracking and reproduction, which sees in the streaming music the apex of the revolution. I must admit that I am not a follower of this revolution. I consider myself as a partisan of the Resistance, instead. To those friends who try in vain of dragging me in this phenomenon, I simply reply that I can adopt this technology when I will be eighty years old and the arthritis forces me to immobility. Nevertheless, until I will be able to set up a cartridge, so much for that. Thus, my approach to the converters is more oriented to understand their potentialities when matched to CD players or transports, in an audiophile contest rather than in a computer contest, which implies the listening of a sequence of concept albums, and not a sterile chain of different musical tracks that you can easily find in a “beach” compilation.


On these premises, I am going to review the Calyx DAC 24/192. The brand is quite new to the high-end world, being a division of the South Korean Digital & Analog Company LTD that is specialized in Class D integrated amplification. The digital calling jars with the etymology of the term Calyx that comes from a Chinese poem and means “music cup”. It is easy to realize that the DAC has been conceived to be a primary match for a PC, as its style recalls a current mini Apple Mac. Furthermore, it can be directly supplied through the asynchronous USB input, which can receive up to 24 bits/192 kHz data stream, with a support driver for Windows and without a driver for Mac OS X. Among the three work modes - adaptive asynchronous, isochrone asynchronous and pure asynchronous - of the USB interface in connection between computer and external DAC, the pure asynchronous mode has to be preferred because it can eliminate and prevent the problems caused by the jitter, that are the temporal errors which occur in the synchronisation of digital to analog conversion. The digital coaxial input can receive up to 32 bits/192 Khz data stream coming from a CD player. Alas, I am not aware of transports capable of developing a signal at this level of resolution, except, if I am not mistaken, the North Star ones.


The look of the DAC – we have the black version – is extremely minimalist but, despite its small size, the device is very heavy because it has been machined from a solid block of aluminium. This solution offers a reliable security as far as the damping of the resonances is concerned and, in addition, this particular care is not usually traceable in gears of the same price level. On the front panel, there are no controls or buttons, only an isolate small red LED, which turns into violet when the signal from the source is hooked into. On the top there is the D&A Company logo.


On the rear, besides the described inputs, there are two pairs of balanced XLR and unbalanced RCA outputs. There are also two small toggle switches: one selects between inputs, the other the mode of power delivery, either via USB or via 5V wall wart.


The wall wart is required only for S/PDIF transfer and has a very thin structure mostly in the opinion of who, like me, thinks that a well dimensioned power supply, with a filter of quality, can give many vantages in terms of soundstage, transparency and focalization. I also think that Calyx’s designers must have thought a lot about this question. In fact, they have recently realized the external optional Calyx Linear Power Supply, aimed to upgrade the DAC 24/192, which is possible to purchase for 419,00 US $ or, cut down, if bought with the converter.


After the removal of the chassis bottom, what appears is a carving in the metal, where is accommodated a single micro board, upon which all the components are assembled. If the power supply has been considered unimportant, great care has been put up in a crucial spot of the scheme, maybe more determinant than the conversion chip. I am talking about the analog output stage which includes a number of NE5332 opamps, not of top category, but able to offer a determinant contribution in the creation of a good sound. The Calyx has also two clocks that are in synergy with the XS1-L1 processor of the British XMOS and deal impeccably all the data stream comprises between 16 bits/44.1 Khz and 24 bits/192 Khz of frequency. This is something rare to find elsewhere. Evenly amazing is the highly regarded ESS Sabre 9018 chip with 8 balanced channels that provides superior linearity, better S/N ratio and increased dynamic range that allows Calyx to run with a XLR output level of 6,8V.


I have connected the Calyx to my main system with a modified Musical Fidelity E60 CD player and a very good White Gold Reference digital cable. I have repeatedly played a CD for a week in order to reach the necessary and correct run-in. Only then, I have started my test. As usual, the first thing I needed to know was the noisiness. The outcome has been encouraging: total silence on the proscenium and good expectations for my eardrums. Meanwhile, in the semidarkness of my room, the small LED was winking and with its violet contour, it was evoking a summer sunset. This atmosphere had put me in a good mood so I spent a couple of days listening to many records in a deep emotional involvement that I always feel when I stay in front of a gear that can give me important sound stimuli. I could not stop: at every session, I felt new signs, new vibrations, and new sensations. I floated off, like casting away in the sound waves, until I realized that I had to write something about and, luckily, two events occurred to help me: the visit of the two ReMusic Executive Editors who, after a pantagruelian gastronomic and ethyl banquet, have had a musical copula (not between the two of them, Ed.) in front of the sublimity of the sound coming out from the loudspeakers: would have been the shrimps, maybe? Secondly, a new neighbour, who cannot distinguish between a piano and a tyre, has forced us to listen at more realistic volumes.


I cannot mention all the records I have listened to, but I will trace the acoustic features of the DAC 24/192 through two works that I often use in my tests: the first one is Hotels and Dreamers, by Allan Taylor, Stockfish Records, 2003. This German cult-label is very famous for its recording techniques. I can cite Direct-Metal-Mastering for vinyl, Pre-Mastering and Direct-Stream-Digital for CD to come up to Direct-Cut SACD. Each recording, before being fixed on the support, has to be submitted to a series of decliking, decrackling, denoising and nova-rendering processes, in order to get a total purification of the musical message. This album, the third work that sees the collaboration with Gunter Pauler and Chris Jones, is an apotheosis of beauty. Besides the warm voice of Allan and his three guitars - a Ralph Brown 185 Custom, a 28H Martin 28H and a Martin D18 - the entire family of instruments - piano, sax, autoharp, accordion, pedal steel, Hammond, violin, viola, violoncello and hollowneck resophonic, squeeze you firmly. The scene is steady, solid, sculpted like the tuft of a young Jerry Lee Lewis, carved in the rock like Moses tablets of stones. The music emerges from the background in all its most recondite nuances. The Calyx expresses a superlative level of resolution, without being sharp or artificial. It enables you to catch the slightest details, which make loud the artistic features that are behind a work of such level. The author himself sings the epiphany of this masterpiece with his mellow tones: “We paid our dues, we took the road and played the game, or win or lose, we chose the Muse”. The art, above all, the meaning of life. The voice is the protagonist, but also the choirs are so focussed that the words are completely intelligible and your brain is free to enjoy the performance. The parts with the piano and those with the strings are likewise convincing and give the sensation of attending the live moment of a studio recording. The DAC shows a great balance with praise worthy three-dimensionality. It shows sweetness and dynamics at the same time, although the impact energy is not so strong between the decay of a note and the formation of the following one. Never before I had felt so fulfilled in the listening of this pearl of modern folk music.


The second CD is L’amore è fortissimo e il corpo no, by the Italian singer Nada, Storie di Note Production, 2001. I adore Nada! I always remember with emotion when, in the backstage, during a concert, she stamped a kiss on my copy of the 45rpm Ma che freddo fa. A mature, experienced, free, committed, very rock woman and singer. Supported by the genial guitar textures of Fausto Mesolella, by the agile double bass of Ferruccio Spinetti, by the piano and jazzy keyboards of Rita Marcotulli and by the powerful drum set of Michele Rabbia, Nada gives us a masterpiece of great intensity. A strong, lyric and violent masterpiece both in arrangement and in the so abrasive lyrics. Listen to Giulia or Meraviglioso and you will understand what I mean. The recording made at the Gaia Worlds Studio in Caserta by Mesolella is simply outstanding. The authority and the vigour of the singing reach frequency ranges out of the ordinary and, in each track, you get the impression that the Italian singer wants to come closer. The bass slams rise in the air making the glasses vibrate, while the medium tones are pure and delicate as well as integrated with the airy and open highs.


All the qualities I have noticed in the Calyx can be improved by using the balance outputs, where, as I told you before, 6,8 Vrms have been measured. What comes out is an improving in all the parameters. Therefore, I strongly suggest these balance outputs.


A remark that I want to raise, not only towards this DAC, but also towards the most part of these kinds of devices, is an excess of “digitality” that could be noisy for the hearing and for the listener’s acoustic perception during prolonged listening tests. In order to attenuate this kind of problem, the most effective solution is to use an interface transformer of good quality. I have been able to verify this phenomenon on the field as the digital sound, with its typical characteristic of being sharp, metallic and cold, became dominating when the converter was matched with the various integrated amps I have at home: Hirtel C45S, Fase Performance 1.0 and Luxman L220. When I have connected the DAC to the Audio Tekne TP8301 MK III transformer preamp, everything has changed and the music has become more ”harmonic”, not at the level of an analogue source, but more natural, realistic and usable.


The listening test of the Calyx 24/192 has been a positive experience. It is not an economic machine, though, especially if you linger on its dimensions and the essentiality of the circuit. The cost is probably due to the massive chassis. There is also the regret about the fact I could not have tested it with the new external power supply: certainly a more performing outcome. However, I assure that, if you have at your disposal a DAC and a pile of good CDs, it is like having a basket of cherries: one leads to another. The more you listen, the more you enjoy. And the music will win once again.



top score ✳✳✳✳✳ ReMusic Sparks

Tone colour: ✳✳✳ 1/2 | Typically digital and a bit cold in standard conditions, it harmonizes itself with an interfacing transformer.

Dynamics: ✳✳✳ 1/2 | Not rousing with the RCA output; excellent with the XLR output.

Detail: ✳✳✳✳ 1/2 | A strength point. The best skill.

Clearness: ✳✳✳✳ | There is a lot of it.

Image: ✳✳✳ 1/2 | With some more measure, a great machine.

Rise time: ✳✳✳ 1/2 | Quite rapid and reactive.

Manufacture: ✳✳✳✳ | The aluminium enclosure is praiseworthy.

Price/quality ratio: ✳✳✳ 1/2 | Not budget, but with a good offer in performances.


Official technical specifications:

D/A Converter IC: ESS Technology ES9018 Sabre Reference 32-bit DAC

Sample Rates: 44.1K-192KHz

THD+N: 0.0005% @ 1KHz, 0dBFS

SNR: 125 dB, A-weighted, 2.2 Vrms

Channel Separation: 140 dB at 1KHz, 130 dB at 20KHz

Digital Inputs: USB, COAX

Digital Input Resolution and Sample Rate:

USB: 24 bits / 44.1K, 48K, 88.2K, 96K, 176.4K, 192KHz

COAX: 32 bits / 44.1K, 48K, 88.2K, 96K, 176.4K, 192KHz

OS Requirement: Windows XPTM, Windows VistaTM, Windows 7TM, Mac OS XTM

Line Output: Unbalanced stereo, RCA jacks with gold-plated contacts

Balanced stereo, XLR jacks with gold-plated contacts

Output Level: 2.2 Vrms (unbalanced), 6.8 Vrms (balanced)

Output Offset: 2mV max

Dimension: 220mm X 220mm X 45mm (Width X Depth X Height)

Weight: 4.4kg

Official Italian dealer: to Palmtop website

Official current price in Italy: 1,300.00 EUR, Calyx Linear Power Supply not included

Associated equipment: to Giuseppe "MinGius" Trotto system

by Giuseppe
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