Mono Stereo Magazine review on the Kassandra DAC Ref II

It is difficult to specify both Aries Cerat as a company and Stavros Danos as the owner/intellectual author of the brand. You can contemplate the design, exotic circuits and implementation of large elements in the state of the art; however, until none of its products are heard, it will be just pure sodium speculation. I had the luxury of hearing your sound preamp a few years ago and I got hooked, but the real step forward in my appreciation came on my visit to Greece, where I was able to experience the complete ultra-high-end Aries Cerat audio system. Aries Cerat falls into the category of extreme ultra-high-end audio niche where things are done in a very sophisticated and elaborate way. Quite the opposite of the “ordinary” high-end audio company.

These days I’m trying to do my homework more deliberately and invest my time in the people behind the brands. This means meeting the people responsible for the design and trying to understand their audio mentality and philosophy. This takes longer, but I increasingly prefer to do things in such a prolific way. There are vast offers of mediocre high-end equipment and more than enough publications are ready to swallow anything. I try to differ and, where possible, dedicate all my enthusiasm and attention to the people, products and brands that activate my internal audio watch and address the qualities most important to me.

So what’s so different about Aries Cerat?

Well, what else then the person behind this. Stavros Danos is an extremist by nature and a man who cannot stand still at any time. When we met with him in Athens, we spent days and hours addressing different topics of interest. It was a really inspiring and very positive experience. Stavros is both bold and humble at the same time. True rarity these days in the world of infinite journeys of the mind of the hollow ego. A good dose of audacity, which comes from hands-on experiences and mileage, allows you to create high-quality audio equipment that stands out and differs greatly. All of this goes back to his younger age, to be exact, started when he was 14. Not many people know, but he was a thriving aeronautical engineer with very few career offerings from the most prominent international aerospace companies. He has chosen a different path and something he loves and appreciates very much. The music!

There is only one key factor, leading to the creations of the high-end audio equipment with the most advanced state-of-the-art art art, and that’s pure love and respect for music. This is what turns on the creation of completely unique products and stamps them with specific sound DNA. In electronic design it is always about the question of elections. Well-thought-out decisions create a specific polling circuit that can reflect music as it is or take a boring and squeazy route. Stavros Danos let his creations speak for themselves. They’re their “babies” and they carry the strongest message. Stavros ad hoc is not only able to navigate the wave of the past … His innovative mind constantly challenges the level of his know-how. This is the only way to do things in ultra-high-level audio and something I find with other people in the industry like Robert Koch, Rumen Artarski, Angel Despotov, Lee Paul Dalby, etc.

There is no simple and quick way to design something special in audio. It requires continuous effort and a deeper understanding of the inner workings of electronics. Even with talent you can go so far. There’s a steady push towards her. Even reaching a certain plane there is no stop. This falls into the category of literary work 24/7. These people drive with the passionate perpetual mobile self-mechanism, which cannot be taught or purchased! Stavros Danos is undoubtedly a member of this extreme league of distinguished audio knights. Not always a title and throne of the most desired efforts. We’re talking about the plane where even the most exotic designers stop and settle for the results and stop. Rare people like Stavros will not align with this criterion. This is why your equipment is more powerful in size, uses large components, and gets materials from other industries when the typical audio supply chain doesn’t guarantee what’s needed. Satirically, but even the real bones. Aries Cerat products are not large. They are what Stavros likes to point out, simply designed properly.

DNA

During the process of creating and building the company, in the earliest stages, the need for a true SOTA source was mandatory for Aries Cerat. You cannot claim that there are built speakers that pretend to be the best designs of top amplifiers, etc., if you do not have a true reference source. And for Stavros Danos the reference means the reference in the real context. The font must be absolutely perfect to create something special and difference. Stavros began to develop the Kassandra as he did not believe that any source on the market faced the task. “There would always be a certain character, lack of dynamics, lack of musicality and true timbre and analog flow … and these drawbacks would be projected to our efforts to create the best amplifier and speaker combo possible.”

Kassandra’s prototype was developed very early, not as a commercially available design, but as a free object lab tool, Stavros’ personal reference tool for speaker and amplifier development. The decision to get into production and be commercially available was decided at a very later stage. “Since then, we have found many new converters that are released daily, with impressive paper specifications, but did not reach what we call analog sound. They always presented, electronic signature that gives digital reproduction a bad recognition. Stavros’ goal was to make a true analog source, which takes Ones and Zeros as input. “And I feel like we’ve been successful.”

When things are taken to the extreme, only ladder DACs can deliver maximum performance

Ladder DAC is a resistance network switched by a series of switches, with n being the bit depth. It is a type of passive procedure, where Delta Sigma technology, as it develops and advances, is a completely different conversion procedure. Delta Sigma converters were developed because it is much cheaper and easier for the integrated circuit company to manufacture a Delta Sigma modulator. The manufacture of an R2R DAC, which includes costly procedures such as laser cutting of resistors with an accuracy of 1/128000, its value is a completely different, time-consuming and costly operation. The precision required to create a linear R2R converter is of a different plane.

Creating an analog signal from noise shaping, as in Delta Sigma conversion, sounds counterintuitive. While very complex and very high order filters that are implemented to reconstruct the analog signal, from a burst of noise, do a good job of creating very good specifications on the failing paper. The high complexity of the filters and the very high energy of several kHz-MHz that noise is present is what gives all Delta Sigma converters their distinctive sonic signature. A sound attribute often associated with the term digital sound.

Back in the R2R principles. Individual resistors must be laser trimmed with incredible accuracy, while extremely high precision measurements are made. Unfortunately, this process is not available for small batch manufacturers. It is virtually impossible to achieve the accuracy of integrated circuits with discrete resistors. Even random welding resistance could ruin low-level linearity. Aries Cerat chooses R2R IC, specifically a highly prized AD1865Nk converter. Many DACs use IC converters in the usual “datasheet application” circuit, simply by adding their analog stage and ready. Stavros Danos deliberately designed a converter, which uses several R2R IC converters as components of a new conversion system.

The AD1865Nk has very direct data handling logic and does not process the data flow in any way. This gave Kassandra DAC the freedom to completely exploit the IC of its converter system.

For example, the input data is locked and directly updates the resistor network without any additional complex logic or data handling/processing. Aries Cerat’s unique SuperClock circuit resynchronizes directly and controls the “update” signal. In this way, absolutely no additional jitter is induced in the conversion. This is not possible with any other IC converter, as there is always internal logic and data handling, which greatly impair vibration performance, even if the clock input is close to being perfect. The massive banks of IC converters act as parallel switching resistance ladder converters, thus canceling the deviation of the actual resistance values from the theorists. If the resistance value deviation of the ideal is Gaussian (which is), as the number of parallel resistance networks increases, the deviation of the ideal standard is set to zero. This is why parallel R2R converters improve linearity.

Noise figures are improved, on the same principles

The Kassandra converter is operating in complementary mode. This means that each channel consists of two converter banks that are “reflected”, perfectly synchronized and paired, thus improving the low-level linearity (linearity near the “zero” value) as well as their lower noise. The Kassandra was developed to be an absolute audio source, not just another DAC on the market. Stavros extended the limits to the maximum and walked an additional mile in many respects, wishing to have the best for the development of his products.

Many technical solutions implemented are not usually found in commercial DACs, as Kassandra was not developed to be one of them.

  

JITTER

The endless war on jitter is fought in Kassandra with many techniques to reduce and cancel it both passively and actively. Bounce signals, oversteer, low rise times, etc. Stavros Danos solves this by using special driving circuits and carefully adjusted digital line terminations for all digital signals.

Interference between digital lines, background noise, and power supply noise is an important source of fluctuations. Kassandra implements extensive LC filtering (using high-loss RF coils and high-speed capacitors) with all integrated circuits, power circuits, and logic circuits to solve and solve this problem. Jitter originating from USB and SPDIF/Toslink sources is removed directly on the enabled conversion line, or at the “update” signal point of the converters.

When implementing ICs, there is no complex data handling logic or multi-stage data logic, the timed signal very accurately resolves to a conversion without extremely accurate jitter. This is not possible with any other converter. The Super Up clock locks the XMOS asynchronous USB controller again, as well as the SPDIF receiver. Jitter is very audible and Stavros felt that the dichotomy should end. That’s why digital input re-clock circuits are bypassed on the fly and each demanding audiophile can cause an AB to compare the fly to the turn of a knob.

IV

R2R integrated circuits are current output devices. Its impedance is very high and is close to an ideal current source and the current must be converted to voltage. Most converters involve Opamp circuits, from complex virtual terrain schemes to simple circuits that use a resistor to perform IV conversion, followed by a buffer. Aries Cerat Kassandra two complementary output converter banks operate in differential current mode. This should be converted into a single-end voltage output and Kassandra employs a specially designed transformer, which converts the current differential into a single-end voltage output.

Many argue that the best current-to-voltage converter is an inductive element. Stavros Danos avidly follows this logic, as it feels that the acquired performance of the specially designed transformer is second to none compared to the many alternative IV methods it tested and widely compared.

ANALOG STAGE

The analog stage in Aries Cerat Kassandra DAC is a small single-termination tube amplifier consisting of a transformer-loaded tube driven directly by transformer IV and predisposed with ultra-low noise polarization power supplies. The E280F tube was chosen for a reason, as it is the best probe tube in the supercube valve family. It is a connected triode with specific parameters such as transconductance, plate impedance and especially linearity and noise levels above any small signal tube. The triode is loaded with a special quality large core reducer transformer. The SE triode amplifier is powered by large power supplies, with double filter with coils and high-speed, high-energy capacitor banks.

As you can see, nothing with Kassandra is left to chance and designed in a simple way. This is shown in your sound and how Stavros Danos logic translates to music.

MUSIC

Technical part of the Kassandra is being addressed so far. Now to logical progression and big question. All the complexity and exotic taking of electronic media a little without bringing the sound to the stratosphere of the upper step. Where does Aries Cerat Kassandra DAC belong? Sound performance was as resolute as the digital technical approach. Kassandra brings the conversion from analog to digital to the new realms, and especially for the given price, not only represents a real jewel of audiophile, but a bargain comparison with what some much larger and more established names are charging for their praised products. It’s one thing to buy your reputation and comments along the way. He really deserves it, it’s a completely different story….

Let me immerse myself in the sublime universe of music with the guide of the audio submarine Aries Cerat … János Starker Variations on the theme of Paganini KODALY is my album to listen to at night, recovery and critical listening. I simply adore the fiery virtuosity of János Starker. It can encapsulate the pure purity of music without any trace of the clinical agenda. That’s not uncommon. It’s beautiful. Many of the audiophiles and music lovers strive for a more “soft” and “sweet” exit from Yo-Yo Ma. I’m strictly after the raw emotional interaction. My home is closed by Starker’s lyricism and the total performance of Bach, Paganini, Kodaly…

Aries Cerat Kassandra presented this album with phantom resolution, wonderful transcription and with a complex extravagant energy. This level of raw energy impact and the details presented were a complete surprise and an instant conundrum that was further solved with Joe Pass’s Stella de Starlight from her legendary virtuso album. Two different instruments, which were never easy to reproduce with full contouring and power through a digital source, were formed unrestricted and acoustically refined with the future variability and richness of captivating string disintegrations and delays. Something conventional types of DACs can’t even get close to. And what to talk about about transparency and the details that are being solved … When it comes to rebuilding the overlapping notes of string instruments in most cases, and even with top-notch digital fronts, the actual presentation lacks the absence of truncated note phenomena. With real music, when the decline of the previous note is still present and a new note is being introduced with your fingers or with the arc, multiple harmony evolves. Things go crazy pretty quickly when the DAC can’t follow reflection and harmonic decompositions rather than materializing without ring gaps, they become a lifeless and absent from harmonic wealth. There is no continuity equation that is mandatory for any serious reproduction. Standing still appears leaving the unsused. Lifeless audio experience. Instead of filling and aligning notes without any space, regular digital playback introduces a low-resolution grain resolution. On the contrary, the palpable contour and harmonic richness of Aries Cerat Kassandra strikes immensely with a rocket speed. Cassandra easily transmitted the semper stempcate with a slight rubate. Where notes usually become insensitive, Aries Cerat DAC solved floating nature as the most natural way to transcribe. Peaceful whimsical step with the best analog playback attributes.

With the playback of classical music at the top level there is a mandatory complex density that must be served to justify not only the price, but also the designation of high-end and high-end audio. Not everything is subordinate only to the level of information being served. It’s a much deeper task.
Without proper transmission of the articulation and passage to the core of musical DNA, the reproduced reality sucks and translates into vituperations rather than the intrinsic/intrinsic simplicity of musical language. Instead of the lyrical formation of “It’s a braw bricht moonlicht nicht”, the opposite negativity often conveys completely different musical experiences. When the system is configured correctly and served by the powerful source, the result should be relaxing, empowering and satisfying. This is where Aries Cerat DAC shines, which are not a little marginalized, and join the music without trying to be preteeze. As I have often said, each product reflects the designer’s mindset, it is no different with Kassandra MK2. This DAC is a clear reflection of Stavros Danos’ letter and love of music. It is not easy to translate the audio message to the level close to the original music message. Consonable to quickly transform into dissonance with most DACs (yes, even at absolute prices) where clear notes to quickly assume the role of an atonality rather than a perfect sum of tone, creating a pleasant harmony. The magnitude of the rights with Kassandra reached the point where the actual boundary moved with a twist, creating a serious challenge.

Kassandra MK2 released. Transfer digital audio playback to a much higher plane and in intriguing realms. Climbing the ladder so high along with the long mileage requires a little more depth in the musical journey. For the designer and listener. At this point it’s not about the ego journey. It breaks down into the conclusion that seems simplified. However, the reward of such majestic gravitates continues to be bestowed on each new song in the queue. Kassandra MK2 released. Transfer digital audio playback to a much higher plane and in intriguing realms. Climbing the ladder so high along with the long mileage requires a little more depth in the musical journey. For the designer and listener. At this point it’s not about the ego journey. It breaks down into the conclusion that seems simplified. However, the reward of such majestic gravitates continues to be bestowed on each new song in the queue.

CONCLUSION

Stavros Danos could easily embark on an instant career with one of the leading aeronautical companies. You prefer to choose a very different route and not exactly easy from the ultra high-end audio adventure. Mr. Danos is among the few rare audio designers, who cannot stand still and level with any mediocrity in sound or performance. This is clearly reflected in your products both technically and in the auditory impact.

As a refined exotic shot in high-quality to analog digital audio playback, Kassandra MK2 takes no prisoners. The way everything is reached to the limits and with the parts used, Kassandra not only makes many of the appraisalED DACs embarrassing, but they set up an exemplary price performance ratio value. Aries Cerat as a company by its nature provides a high performance with a completely different price structure to the competition. Any other company that possesses such approaches, solutions and design would instantly double or triple the price, however, Stavros Danos always wants to level the plane where actual performance justifies price. This is where my respect came a long time ago.

Aries Cerat Kassandra MK2 DAC manages to balance the enormous flow of musical energy with the delicacy and overwhelming power that are not heard near or even above their given price. Let me put it relatively polite … Established DACs from high-end audio brands have a lot to want compared to the Kassandra MK2 DAC’s ability to play music as it is. Period!

In the large trend of transparency, Kassandra MK2 DAC mimics the logic of regular audiophiles with the refined version of digital-to-analog conversion. This is by no means your typical DAC, but a deep and complex view of cutting-edge digital audio. Kassandra MK2 is a powerful machine that will quite challenge some minds. It has the unique ability to move technical brains to emotional state with impressive ease. The digitally integrated live music experience should not only be highlighted, but should be praised with Kassandra MK2. In the playback of digital audio per user, almost as a rule, we treat the method of small increments and the law of declining returns. With the product like Aries, the Kassandra MK2 process accelerates with a completely different constant. Kassandra DAC is one of the rare digital products that actually raises the level, which causes the giant to advance and encapsulate performance that reduces analog/digital distance.

What is essential usually comes hidden for your eye work in much more mysterious ways through Aries Cerat Kassandra MK2. One can clearly see and where the money, passion and dedication went.

Nothing really holds up, even when it comes to the technological sophistication of the state of the art called if musical execution lacks a clear breakthrough. With Kassandra MK2, emotional impressions and central musical seeds simply persist after listening and demand another musical “turn.” It is always an axiomatic exploration and, unless one tested every exotic DAC on the planet under replicable conditions, the final conclusions can be questionable in nature. Boldly and boldly my assumptions stand firm. I have done my homework and won a great mileage with great quality time that is spent with super, exotic and high priced DACs. Without hesitation, Aries Cerat Kassandra MK2 clearly embarks on the throne of the highest performance converters without even lurking in Pandora’s price box. With the Signature version in a few weeks, I’ll be able to level out how Stavros Danos contemplates pushing things beyond what’s possible in the digital domain. So far, this is the DAC that materializes an intriguing idea about a source to serve everyone…

Mientras que otros DAC podrían estar en el nivel de Vieux Château Certan, Latour à Pomerol or L’Eglise-Clinet; Aries Cerat Kassandra nails him with the wealth and integrity of a single 61 Pétrus. And let me summarize the perfect quote related to my internal review/test work and dare to say how Stavros Danos pursues the task of higher order and the path of cutting-edge musical reproduction… “One must get rid of the bad taste of wanting to agree with many.” Well, “it’s no longer good when your neighbor says so. And how should there be a “common good”! The term contradicts itself: what can be common always has little value. In the end, it must be as it is and always has been: great things remain for the great, chasms for the deep, nuances and shudders for the refined and, in short, all that is rare for the rare. “- Friedrich Nietzsche.


I am more than happy to award the Aries Cerat Kassandra MK2 DAC with Mono and Stereo Editor Choice Award …
Text – original photos: Matej Isak