Like with cartridges and analog, in general, I have a soft spot for R2R ladder DACs. A few years ago, they’ve literary dragged me back to the high-performance, high-end digital audio. So, when Etalon Sound asked me if I want to dig deeper into their very Dream DAC, I’ve asked for a bit more info.
The technical concept and white paper were more than interesting and not too long after the review sample arrived.
THE ETALON SOUND WAY
Accomplishments of the high-performance audio’s past, and, on top of it, our determination to stay open-minded about all the changes, which recently took place in technologies, demography, economics, lifestyle, distribution of music, etc.
Etalon Sound company is a “metier”-type business, which manufactures a unique state of artline of home electronics and speakers.
Etalon Sound applies their quarter of century’s worth of “hardcore” audiophile legacy and many years of serious music recording experience to design and execution of our products, which we want to position within the most up-to-date contexts of elevated demand.
As a matter of fact – as part of that industry – Etalon Sound is fully aware that High-End Audio’ s arsenal is fully capable of replacing the (enormously expensive) venues as an art form creation link, where an arsenal is an art form in itself, the way the exceptional venues are.
Which new, or, different, consumer needs can High-End Audio products satisfy, that ordinary – and sometimes much less expensive – equipment cannot?
Actually, the whole raison d’etre of the High-End Audio from its very inception was mainly educational: it is supposed to be the most effective tool for mastering a new (for the vast majority) “musical language”.
Therefore, the latter is both its main exclusive feature and its main functionality trait.
HIGHLIGHTS
- PLD-based USB module with a new algorithm for I2S signal shaping
- High-precision clock generator (femto clock) and data buffer
- Fully balanced circuitry, from R2R-arrays up to the output stages
- Twelve R2R-arrays, six in each channel
- Ability to work without a preamp; Synchronous volume control of a new type
- A new algorithm for low amplitude signals processing
- Galvanic decoupling between analog and digital circuits of the converter
- Connections and winding elements (transformers, coils, etc.) are made with True Symmetry wire
- Power supply with Double-Ring wire capacitors
- High-class component etc. Neutrik sockets and custom-made high-precision wire resistors
- Cabinet with high dumping properties; It’s milled out of a single aluminum block
- Remote control and touch screen control
THE WARM HARTH
Dream DAC was designed from the ground up with a clear goal of replication the warmer, dark nature of live music. In the era where everything is forced into the brittle realms, Etalon Sound is pursuing the attributes of the natural sound that embraces the recognizing qualities of live music.
The Dream DAC is the realization of our intentions to transmit initial characteristics of digital sound record into a real, natural sound. Such operations as amplifying with nonlinear elements, oversampling, transmitting of the digital signal via industrial microchips or through the USB tract interfere on signal making it different from its original.
The Dream DAC is free of any negative influences of an amplifying the sound after conversion. You can get natural sound without any interferences that could be brought in by filters or preamp circuitry. There is no harmonic distortion from amplifying at all. The Dream DAC is based on Etalon Sound’s laboratory developments. The main of them is Super R2R technology. Each Super R2R matrix is an active matrix, so at the result, the DAC is powerful DAC, with spirited live sound, able to drive headphones or an AMP without a preamp. A total number of powerful elements of matrixes is over a hundred. There is a system of a synchronous volume control for using DAC with headphones.
Super R2R technologies enable to approach to an absolute sound fidelity and it stands on the highest quality level obtainable by digital-to-analog conversion in principle. These technologies are protected by patents and applications for an invention.
TECHNICAL CHARACTERISTICS AND PARTICULARITIES
New synchronous volume control
Another advantage of Super R2R technology is synchronous volume control. There are two fundamentally different approaches to the volume control in Hi-End — a digital and an analog one; each has its own major flaws. Etalon Sound designed a new way of volume control suitable just for the R2R array. It’s neither digital nor analog in the current interpretation of these terms. It is based on synchronous changing of the logic value of ‘1’ reference voltage in the converter and enables to control volume without changing the original digital code. At the same time, it has no drawbacks inherent in the analog control method.
Converter based on balanced R2R circuit
R2R circuit is a classic converter layout realizing the most accurate way of digital-to-analog conversion.
The sound of R2R array based converter without oversampling (NOSDAC) is more natural than the one achieved by means of other circuits with oversampling and digital filtering.
Classic R2R array has a flaw associated with the problem of signal conversion while virtual zero crossings. At this moment all logical circuits are switched simultaneously and even tiny non-synchronism causes an overshoot of stray impulses (the so-called glitches).
In Super R2R virtual zero crossing poses no problem because R2R arrays have balanced discrete sign-magnitude hybrid ladder topology. Positive and negative half-waves of the signal are processed independently, each by a separate array and are mixed only at the output. As a result, there’s no virtual zero crossing at all and no corresponding problems!
Power supply
DAC power is divided into digital and analog and is implemented on 3 custom-made toroidal transformers. To power each R2R board, special power supply was developed, consisting of stabilizers, wetlands (Virtual Battery Device) boards and a Double Ring Capacitor of its own production for final power filtration
A new algorithm for low-level signals conversion
This new algorithm enables to fulfill the sound potential of low amplitude signals that otherwise are reproduced either with distortion or remain completely obscured by noise and inaudible.
The new algorithm for low-level signals conversion is realized by means of a three-stage circuit; a single R2R array is divided into three parts. Each part is a separate R2R converter processing its own fraction of the signal — having an either low, medium or high level. The low-level signal ends up being shaped by a chain of not 24 resistors the way it’s done in the conventional R2R converter (with 24 digit capacity) but by 8 resistors only resulting in a dramatically shortened signal path. This technology provides for careful handling of any low-level signal.
Besides the digital code’s least significant bits get an additional gain before conversion and are again brought to normal level afterward.
All in all the new algorithm makes the low-level signals noise-free and maximizes DA conversion authenticity in the most important area of low amplitude signals.
Galvanic decoupling of digital and analog converter units
Galvanic decoupling by means of a transformer provides full separation of digital and analog converter circuits preventing from sound quality deterioration by noise and distortions. Transformer cores are made from iron-based nanocrystalline alloy, a new generation material with extraordinary properties. Winding elements are made from ‘symmetrized’ Litz wire. The use of nanocrystalline iron alloy combined with ‘symmetrized’ Litz wire made it possible to design sound transformer, a new generation device with specs and efficiency previously inaccessible.
TUC (True USB Conversion) USB Module
TUC (True USB Conversion) USB Module developed by us provides not only for a transfer of data from computer to DAC but also for feedback to control this transfer process. TUC is realized on FPGA, high-precision clock generator (Femto clock) and signal buffer. It uses a unique algorithm for generating an I2S signal. High-precision clock generator has minimal phase noise and is located in close proximity of the converter.
THE MUSIC
No matter the genre Etalon Sound Dream DAC organic fluidity was always inviting and welcoming for the returned listening.
Moon River from Edward Gerhard – Henry Mancini: Pink Guitar Acoustic Guitar Solos is a great example of pure and simple rendition where the energy coming from the front end should accumulate more than usual density to portray the much-needed level of harmonic intensity. The timbre, tone, and color can be too easily smeared if the DAC is not ticking at the proper level. The Dream DAC quite easily followed Edward Gerhard’s vibrant rendition of the timeless classic with a higher degree of overtones. 
Dream DAC comes with a warm nature but is not overflown. This was easily noticed and verified with the Our Spanish Love Song by Charlie Haden, Pat Metheny from the album Beyond The Missouri Sky. Haden always preferred his bass to be recorded with a tube preamp and it the thick richness of his tone can be instantly oversaturated.
Etalon Sound DAC managed to keep a bit warmish imprint within the non-push forward realms. This allowed Haden and Metheny tone to be still easily recognizable and not sounding too steep or at forte.
Waltz New from album Power Of Three (Michel Petrucciani, Jim Hall, Wayne Shorter) lyrical interplay was nimbly followed with the Dream DAC. Again the purity of jazz guitar tone was of spryly origin and piano notes expanded with longer decays than expected. 
The Etalon Sound DAC spatial resolution was challenged with Viktoria Tolstoy/Jacob Karlzon rendition Genesis/Phil Collins of Taking It All Too Hard from the album A Moment of Now. With Dream, DAC Karlzon’s piano notes had enough space to linger and Tolstoy’s vocal enough forte to offer an objective a higher degree of believability. 
Playful Symphonies Nos 29 & 38 (Herbert von Karajan – Mozart) poses a certain feather-like quality and tempi that can be swiftly masked when DAC doesn’t possess enough potency to present Playful Symphonies with enough cogency. Etalon Sound DAC puissance inner nucleus again has proven to have a lustrous heart ready to deliver even more complex musical structure. 
Nordic heart!? Requiem, for 4 voices, choir & orchestra (Lacrymosa Bo Hansen, Kristiansand Symphony Orchestra, Norwegian Soloists Choir) that appears on The Nordic Sound by 2L, one of my favorite contemporary labels was another distinct evidence of Dream DAC capacity of digging deeper into the atmospheric and spatial zone. Dream DAC allowed portraying the drama and sense of a scale, that could without a grander effort establish an interactive-emotional bond. My listening notes also pointed at the horizontal and vertical expanse, that was more than fitting at the Dream DAC’s given price. CONCLUSION
So if I needed to sum up the Etalon Sound Dream DAC’s raison d’etre what would it be?
Dream DAC is all about music, timbre, tone, and color. It belongs to the DACs that quickly and instantly lets you immerse into the music, at once bypassing the overdose of the left brain hemisphere’s logicians guarding.
Audiophiles and music lovers that particularly cherish tone of the instruments will find a happy home with the Dream DAC. Dream DAC can convey the rich palette of tonal density that is not easy to find. This makes it an interesting and potent partner for the systems that might be to a bit too open and need a slight, but welcoming dose of a tonal balance.
Despite being voiced on the warmer side, Dream DAC still provides a plethora of micro and macro details.
Dream DAC is by no means the usual affair. There are quite a few unique electronic-inner-design choices that differentiate it from many of the DACs on the market that simply combine a multitude of shelf modules and parts.
Super R2R technology, fully balanced topology, synchronous volume, TUC USB Module, iron-based nanocrystalline alloy transformer cores, R2R array shortened signal path, etc. and most importantly the luminous sonic quality really makes Etalon Dream DAC quite an interesting competitor in the price range that is very dense.
Dream DAC impressive implementation of volume control also makes it even more interesting with the ability to drive power amplifiers directly. I’ve had no problem properly driving my Lamm M1.2 Reference hybrid power amplifiers with the dream DAC. The lock and load were unexpectedly well matched with enough gain to enjoy even the tracks recorded very quietly.
From Russia with a lot of love! Etalon Sound Dream DAC was designed by music lovers for music lovers! The end result shows, that Dream DAC was no happy accident, but a project that embraces both technical proficiency and prolonged evaluation path. Yes, unlike many of the DAC, I have no doubts that Dream DAC went through prolonged listening sessions.
PRICE
– 10.000 EUR
TECHNICAL SPECIFICATIONS
Digital inputs:
Coax: 1xRCA (S/PDIF) 1xXLR (AES/EBU): 24bit 44.1-192k PCM
True USB Converter (TUC USB):16bit 44.1-192k PCM
USB: 24bit 44.1-384k PCM
2x Optical (Toslink): 24bit 44.1-192k PCM
Analog outputs:
XLR and RCA unbalanced analog stereo outputs
XLR balanced direct Super R2R matrix analog stereo output
Headphone output:
4 pin XLR balanced
6.3mm / 1/4″stereo jack unbalanced
Outputs characteristics: THD+N: 0.003% or 90 dB
XLR balanced max. voltage: 6.4Vpp(SE); 12.8Vpp(XLR)
Miscellaneous:
3 control switches
IR remote control
Dimensions: 440 x 315 x 91 mm
Weight (net): 11 Kg
CONTACT
Etalon Sound
Electrozavodskaya str. 21
Moscow
Russia
Web: http://etalonsound.com
Tel: +44 (0) 208 133 3892 (UK, London), +7 (916) 302 08 87 (Russia, Moscow)