Mar 222012

Calyx Audio were a new name to me when I first saw one of their attractive hewn from solid DACs at the March Audio World show last year. The DAC was being used as part of a computer audio set up and if I am honest that aspect of things turned me off slightly.

I am and I make no apology for being so, against virtual music listening, i.e listening to music from files. I realise that the music industry is going this way and I also realise that like King Kanute I am standing in the waves of digital downloads and changing listening trends but the only digital I listen to comes from CDs/SACDs or DVDAs. Behind the times? Yes and proud to be so. I prefer physical media as the carrier of the books I read, the movies I watch or the music I listen to.

After agreeing to do this review I decided as the computer audio aspect of this product has been covered already that I felt that examining the red book performance more closely was where I would concentrate this review and in the light of some negativity being sent the Calyx’s way re this aspect of performance I felt even more so that this was the right area to look at.

Calyx Audio are a relatively new South Korean company having been formed in 2008 as a spin off from Digital and Analog (formed in 1999  to develop Class D amplification based on a joint project with Samsung) However by 2008 D&A decided to go their own way and produce high end audio products under the Calyx brand name.

By 2010 D&A began work on a design using ‘an asynchronous USB DAC using Xmos’ IC and ESS Sabre 9018’, the result of that is the product I have in front of me for review.


The unit I was sent for review, came well packed in a neat box with all the accessories plus, software (unused), a USB lead of reasonable quality (unused) and a mains PSU with numerous plug in adaptors (non fixed so therefore another connection between the PSU and the DAC).  The DAC was beautifully made (available in black or silver finish) and very heavy considering the size. However after removing the bottom plate, I found that all the weight was in the case, which had been hollowed out only in one place by a CNC machine to fit the compact electronics and socket mountings.

I must say that I was really quite shocked at this discovery and how little was actually inside the case. In fact even keeping the design as it is, the case could be at least half the size and thus save the perspective purchaser a fair bit of money. Frankly I don’t understand why so much extra material was specified for this design, as very little of the potential case is actually used.

Fit and finish is lovely, with the surface of the DAC being beautiful as is the recessed logo  and all the sockets and switches are neatly fitted on the rear of the DAC. There is two RCA outputs, two XLR outputs, an RCA digital input, USB input a tiny toggle switch to select between them, the mains input and the power on off, again via a tiny toggle switch.

The DAC uses an ESS Technology ES9018 Sabre Reference 32-bit DAC and has 44.1K-192KHz sample rates. The USB input can handle 24 bits / 44.1K, 48K, 88.2K, 96K, 176.4K, 192KHz and the RCA/Coax input can handle the following  32 bits / 44.1K, 48K, 88.2K, 96K, 176.4K, 192KHz.


I used my Moon Andromeda CD player, Micromega Classic Data transport, Audiomeca Mephisto 2 CD transport, Olive 4HD as sources and amplification was Chapter Audio Signature pre-amplifier, Chapter Audio Couplet power-amplifier. Speakers were Anthony Gallo Reference 3.1 and 3.5 speakers. All equipment sat on Clearlight Audio Aspekt racks. Signal/speaker cabling was a mixture of TrusoundZ, Atlas Mavros, with mains cables being in the main TrusoundZ (preamp, power-amp) and Audience AU24 and Analysis Plus Power Oval 2. Digital connecting cable was the TrusoundZ Revelation TSZ-0015. No mains regenerators or filters were used during the review.

While doing this review I was also reviewing the Deltec Precision Audio PDM3 and as with that DAC I found once again that the quality of the transport used made a marked difference to the overall performance, thus my findings with the Calyx were dependant on which transport was used with it and I found it sounded a lot better with the Audiomeca Mephisto 2 transport than with the Micromega Classic Data, as was also the case with the Deltec DAC. The review was done with the Mephisto 2 as transport and an Olive 4HD was used as a source for 24bit 192 tracks.


I used a wide range of music but in the main, re the core review I used tracks from the following albums.

Thomas Dolby – Aliens Ate My Buick

Nitin Sawhney – Beyond Skin

The Dali Demo CD

Jazz Side Of The Moon The Music of Pink Floyd Sam Yahel, Mike Moreno, Ari Hoenig, Seamus Blake. HD Track 24 bit /192 khz

Listening (Red Book)

I know there will be those that moan about the fact I have not used a computer as a source and thus have not tried the USB input (which some other reviews claim is better than the RCA Coax input. I have even heard some say that the coax input is an after thought) and thus I may well not be giving a full review here and while I think that is a fair comment, and I will concede that point, I would however like to point out that not every audiophile who might want a new DAC will right away be dipping their toes into computer audio. In fact many might well want to upgrade an older CD player and or use a server such as the Olive 4HD as a transport and it is for those that this review is mainly aimed and not the new generation of computer audio enthusiasts (1)

After a fair bit of running in (not knowing how much had happened before hand, as this unit was not brand new) I sat down to listen and I found that the Calyx sounded better with the TrusoundZ Revelation TSZ-0015 digital interconnect I reviewed recently that my XLO one and also as I have found in the past this DAC also sounded different depending on the transport used. I feel this is much like a cartridge performing better in a higher quality arm and turntable than a cheaper one. I know there will be those objectavists who cry that bits are bits etc but the Mephisto transport outperformed the more than credible Micromega Data substantially; as it did with the Deltec PDM3 as well. This improvement was heard in the areas of the soundstage, which widened, gained depth and height, as well as the tonal palete being richer too. All in all music played via the Calyx Audiomeca Mephisto combination sounded very good indeed.

With all the music I played the Calyx’s sound consistently sat to the slightly leaner more forward side of neutral than the Deltec DAC I had been reviewing recently( still on hand for a comparison) and quite a bit further into the leaner side of things than my reference Moon Andromeda CD player which has a sound that sits just to the warmer side of neutral. In saying all of that the Calyx was still musically engaging and fun to listen to but I would say that re system synergy that a warmer system will be a better match than one that is clean and overly neutral itself. Of course you may well enjoy that type of presentation, so if you do have fun, but for me this would be just a tad too relentless on some types/styles of music.

Having listened via the RCA outputs I had to give the DAC a listen via its XLR outputs and music via this form of hookup sounded much more open and detailed with a wider deeper soundstage and with more weight and scale in the midrange and bass than with the RCA outputs. However coming straight after listening to Deltec’s admittedly dearer DAC the Calyx was a tad veiled, less open and detailed than the Deltec. In fact I would go so far as to say that music felt slightly less substantial and felt thinner via the Calyx. Perhaps it was unfair to compare the Calyx to the Deltec but as it was the only modern DAC I had to hand, and as it is hand built in the UK (higher production costs than Korea) I felt it was a reasonably fair thing to do.

I tried a couple of interconnects I had to hand just to check for synergy re cabling and my findings above were overall the case using either Atlas Mavros XLR to XLR cables or TrusoundZ Revelation TSZ-0500 XLR to XLR cables though I  thought the TrusoundZ were the slightly better match, as music from the Calyx through them had a tad more body and was a little less forward than through the Mavros cables. However regardless of which cables were used the essentially leaner and forward nature of this DAC was preserved. I used the TrusoundZ cables for the rest of the review.

I spent a fair amount of time listening to various types of music, over and above that listed above, and I always felt that something was holding the performance of the Calyx DAC back. Thinking about this more I was left, based on previous experiences that the quality of the power supply can make a big difference to a products performance and thus I had a look at the Calyx’s PSU.

I can’t help but wonder if the poor quality (for £1500 the PSU should in my opinion be better) wall wart power supply was holding back/letting the side down, as it is a weedy affair for a product at this price point. I also can’t help but wonder if a bit less effort had been made with the case work, lovely as it is and had been spent on the PSU then the Calyx would have offered more in regards to its sound quality. Don’t get me wrong here the Calyx is a good product, its just I feel it could have been better if a different emphasis had been put on its construction.

I understand there is a better quality PSU available, but how much further does it push the level of sound upwards and does the resulting cost of this PSU  plus the DAC compete with the sound quality available from DACs in and around that combinations price point? Sadly not having the upgrade PSU to hand I can’t, frustratingly so, answer that question. I should also say that the Calyx can take power via its USB input, but my gut feeling (though I did not compare this option) is that the outboard PSU will provide better sound quality and the USB option is really just for convenience.

Listening (HD Tracks)

Listening to the Calyx with the Olive 4HD as the source, as with the Deltec DAC feed via a TrusoundZ RCA to RCA digital cable the level of sound reproduction took a big leap forwards (in keeping with the superior sound of HD) but not into the same league though as the Deltec had. Money by Sam Yahel, Mike Moreno, Ari Hoenig, Seamus Blake, from the Jazz Side Of The Moon album was open, detailed and powerful, with lovely insights into the playing between the musicians and the subtle phrasing and the textures of instruments was much more obvious than it was via the Red Book version of the track. However the inherent qualities of the way the Calyx presented music was still preserved i.e somewhat lean and forward compared to the Deltec. In some ways the difference in presentation reminded me of the way DVD Audio had sounded against SACD, though the Deltec DAC was never as full or rich sounding as SACD.

As with the Deltec DAC I feel the Calyx feed via a 24 bit/192 signal sounded much better than being used with Red Book CD, however the increase in sound quality is inherent in the HD format and the Calyx sounded pretty good to my ears used with non HD digital. How it compares with other similar priced or cheaper 24/192 DACs I can’t say as I had none to hand.


There have been some comments in other reviews re the inferiority of the Calyx as a DAC to be used with CD Red Book transports but I certainly did not feel short changed by it, listening to music from this format, though it was not as good as the Deltec DAC or my Moon Andromeda this is sort of to be expected as it is cheaper than both of those sources. However the reported superiority of the USB input must surely be countered by the fact that non Red Book material was being used to assess that input and that like SACD/DVDAudio’s superiority to CD, HD is also superior to CD as there is much more band width and information contained in; therefore HD music will sound better.

While I enjoyed the sound of the Calyx, more so via the XLR outputs I can’t help feel but feel that too much effort and cost went into the appearance of the Calyx (interestingly it sounded better with RDC isolation cones under it… go figure) than the design of the PSU and the very fact that Calyx now offer an upgraded PSU suggests that they know that as well. Frankly the rubbish PSU supplied with this DAC, at the price, is very poor in my opinion.

Is the Calyx a good upgrade for an older CD player or to be used with a quality CD transport? The simple answer in my view is yes but the quality of that transport will make a big difference to the final sound you hear. The Calyx is also a good upgrade to a Red Book or HD server such as the Olive4HD especially as those particular items tend not to have particularly good analogue output stages (certainly true of the Olive 4HD) and has been reported elsewhere the Calyx sounds good with a suitable desk computer/laptop as a source.

I feel that careful system matching will be required to get the best of the Calyx and I feel that a system leaning to the warmer side of neutral will serve better in this regard and I can see it working well within a system that uses valves for amplification.

Overall I am left not being quite sure whether the Calyx is good value for money or not as I was unable to compare it to other similar or cheaper DACs, I also felt that two digital inputs only is a tad mean and limiting, however if this number serves your purpose then auditioning the Calyx in your own system is certainly worth doing as it worked well on Red Book and HD format music and I enjoyed having it in my system.


Specifications Manufacturer stated measured performance:

THD+N Ratio 0.0005% @ 1kHz SNR -124 [dB] Channel Separation -140 [dB] @ 1kHz Dynamic Range 123 [dB] @ 1kHz
Output Level (UnBal) 2.2 [V] Output Level (Bal) 6.8 [V]
Main 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 @ 1KHz, 130 dB @ 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
  • Power Source 5V 2A DC Adapter / USB
    Dimension 220 x 220 x 45 [mm]
    Weight 4.4 [kg]
(1) I would point them in the direction of other perhaps more suitable reviews
Manufacturer: Calyx Audio

UK Distributors: Bit Perfect

Retail Price £1500

© Text and Photos Copyright 2012 Adventures in High Fidelity Audio…..except for Calyx product photos and album covers. Copyright belongs with their original publishers.

NB No part or portion of this article may be reproduced or quoted without written permission.

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